[REL] v2.5.2

# v2.5.2

 - [FIX] runtime: make error recovery more robust

.github/workflows/deploy.yml

@@ -14,7 +14,7 @@ jobs:
 
     strategy:
       matrix:
-        node-version: [12.x, 14.x, 16.x]
+        node-version: [20.x, 22.x]
 
     steps:
     - uses: actions/checkout@v2

doc/reference/app.md

@@ -6,6 +6,7 @@
 - [API](#api)
 - [Configuration](#configuration)
 - [`mount` helper](#mount-helper)
+- [Roots](#roots)
 - [Loading templates](#loading-templates)
 
 ## Overview
@@ -65,6 +66,9 @@ The `config` object is an object with some of the following keys:
   needs a template. If undefined is returned, owl looks into the app templates.
 - **`warnIfNoStaticProps (boolean, default=false)`**: if true, Owl will log a warning
   whenever it encounters a component that does not provide a [static props description](props.md#props-validation).
+- **`customDirectives (object)`**: if given, the corresponding function on the object will be called
+  on the template custom directives: `t-custom-*` (see [Custom Directives](templates.md#custom-directives)).
+- **`globalValues (object)`**: Global object of elements available at compilations.
 
 ## `mount` helper
 
@@ -92,6 +96,33 @@ Most of the time, the `mount` helper is more convenient, but whenever one needs
 a reference to the actual Owl App, then using the `App` class directly is
 possible.
 
+## Roots
+
+An application can have multiple roots. It is sometimes useful to instantiate
+sub components in places that are not managed by Owl, such as an html editor
+with dynamic content (the Knowledge application in Odoo).
+
+To create a root, one can use the `createRoot` method, which takes two arguments:
+
+- **`Component`**: a component class (Root component of the app)
+- **`config (optional)`**: a config object that may contain a `props` object or a
+  `env` object.
+
+The `createRoot` method returns an object with a `mount` method (same API as
+the `App.mount` method), and a `destroy` method.
+
+```js
+const root = app.createRoot(MyComponent, { props: { someProps: true } });
+await root.mount(targetElement);
+
+// later
+root.destroy();
+```
+
+Note that, like with owl `App`, it is the responsibility of the code that created
+the root to properly destroy it (before it has been removed from the DOM!). Owl
+has no way of doing it itself.
+
 ## Loading templates
 
 Most applications will need to load templates whenever they start. Here is

doc/reference/props.md

@@ -140,6 +140,28 @@ class SomeComponent extends Component {
 The `.bind` suffix also implies `.alike`, so these props will not cause additional
 renderings.
 
+## Translatable props
+
+When you need to pass a user-facing string to a subcomponent, you likely want it
+to be translated. Unfortunately, because props are arbitrary expressions, it wouldn't
+be practical for Owl to find out which parts of the expression are strings and translate
+them, and it also makes it difficult for tooling to extract these strings to generate
+terms to translate. While you can work around this issue by doing the translation in
+JavaScript, or by using `t-set` with a body (the body of `t-set` is translated),
+and passing the variable as a prop, this is a sufficiently common use case that Owl
+provides a suffix for this purpose: `.translate`.
+
+```xml
+<t t-name="ParentComponent">
+    <Child someProp.translate="some message"/>
+</t>
+```
+
+Note that the content of this attribute is _NOT_ treated as a JavaScript expression:
+it is treated as a string, as if it was an attribute on an HTML element, and translated
+before being passed to the component. If you need to interpolate some data into the
+string, you will still have to do this in JavaScript.
+
 ## Dynamic Props
 
 The `t-props` directive can be used to specify totally dynamic props:

doc/reference/slots.md

@@ -201,16 +201,17 @@ use this `Notebook` component:
 
 ```xml
 <Notebook>
-  <t t-set-slot="page1" title="'Page 1'">
+  <t t-set-slot="page1" title.translate="Page 1">
     <div>this is in the page 1</div>
   </t>
-  <t t-set-slot="page2" title="'Page 2'" hidden="somevalue">
+  <t t-set-slot="page2" title.translate="Page 2" hidden="somevalue">
     <div>this is in the page 2</div>
   </t>
 </Notebook>
 ```
 
-Slot params works like normal props, so one can use the `.bind` suffix to
+Slot params works like normal props, so one can use suffixes like `.translate`
+when a prop is a user facing string and should be translated, or `.bind` to
 bind a function if needed.
 
 ## Slot scopes

doc/reference/templates.md

@@ -18,6 +18,7 @@
   - [Sub Templates](#sub-templates)
   - [Dynamic Sub Templates](#dynamic-sub-templates)
   - [Debugging](#debugging)
+  - [Custom Directives](#custom-directives)
 - [Fragments](#fragments)
 - [Inline templates](#inline-templates)
 - [Rendering svg](#rendering-svg)
@@ -80,6 +81,7 @@ needs. Here is a list of all Owl specific directives:
 | `t-slot`, `t-set-slot`, `t-slot-scope` | [Rendering a slot](slots.md)                                    |
 | `t-model`                              | [Form input bindings](input_bindings.md)                        |
 | `t-tag`                                | [Rendering nodes with dynamic tag name](#dynamic-tag-names)     |
+| `t-custom-*`                           | [Rendering nodes with custom directives](#custom-directives)    |
 
 ## QWeb Template Reference
 
@@ -588,6 +590,35 @@ will stop execution if the browser dev tools are open.
 
 will print 42 to the console.
 
+### Custom Directives
+
+Owl 2 supports the declaration of custom directives. To use them, an Object of functions needs to be configured on the owl APP:
+
+```js
+ new App(..., {
+    customDirectives: {
+     test_directive: function (el, value) {
+            el.setAttribute("t-on-click", value);
+       }
+   }
+  });
+```
+
+The functions will be called when a custom directive with the name of the
+function is found. The original element will be replaced with the one
+modified by the function.
+This :
+
+```xml
+<div t-custom-test_directive="click" />
+```
+
+will be replaced by :
+
+```xml
+<div t-on-click="value"/>
+```
+
 ## Fragments
 
 Owl 2 supports templates with an arbitrary number of root elements, or even just

docs/owl.js

@@ -1625,6 +1625,13 @@ function makeRootFiber(node) {
             fibersInError.delete(current);
             fibersInError.delete(root);
             current.appliedToDom = false;
+            if (current instanceof RootFiber) {
+                // it is possible that this fiber is a fiber that crashed while being
+                // mounted, so the mounted list is possibly corrupted. We restore it to
+                // its normal initial state (which is empty list or a list with a mount
+                // fiber.
+                current.mounted = current instanceof MountFiber ? [current] : [];
+            }
         }
         return current;
     }
@@ -1741,6 +1748,7 @@ class RootFiber extends Fiber {
         const node = this.node;
         this.locked = true;
         let current = undefined;
+        let mountedFibers = this.mounted;
         try {
             // Step 1: calling all willPatch lifecycle hooks
             for (current of this.willPatch) {
@@ -1760,7 +1768,6 @@ class RootFiber extends Fiber {
             node._patch();
             this.locked = false;
             // Step 4: calling all mounted lifecycle hooks
-            let mountedFibers = this.mounted;
             while ((current = mountedFibers.pop())) {
                 current = current;
                 if (current.appliedToDom) {
@@ -1781,6 +1788,15 @@ class RootFiber extends Fiber {
             }
         }
         catch (e) {
+            // if mountedFibers is not empty, this means that a crash occured while
+            // calling the mounted hooks of some component. So, there may still be
+            // some component that have been mounted, but for which the mounted hooks
+            // have not been called. Here, we remove the willUnmount hooks for these
+            // specific component to prevent a worse situation (willUnmount being
+            // called even though mounted has not been called)
+            for (let fiber of mountedFibers) {
+                fiber.node.willUnmount = [];
+            }
             this.locked = false;
             node.app.handleError({ fiber: current || this, error: e });
         }
@@ -2270,6 +2286,12 @@ function collectionsProxyHandler(target, callback, targetRawType) {
 }
 
 let currentNode = null;
+function saveCurrent() {
+    let n = currentNode;
+    return () => {
+        currentNode = n;
+    };
+}
 function getCurrent() {
     if (!currentNode) {
         throw new OwlError("No active component (a hook function should only be called in 'setup')");
@@ -2598,42 +2620,47 @@ class ComponentNode {
 }
 
 const TIMEOUT = Symbol("timeout");
+const HOOK_TIMEOUT = {
+    onWillStart: 3000,
+    onWillUpdateProps: 3000,
+};
 function wrapError(fn, hookName) {
-    const error = new OwlError(`The following error occurred in ${hookName}: `);
-    const timeoutError = new OwlError(`${hookName}'s promise hasn't resolved after 3 seconds`);
+    const error = new OwlError();
+    const timeoutError = new OwlError();
     const node = getCurrent();
     return (...args) => {
         const onError = (cause) => {
             error.cause = cause;
-            if (cause instanceof Error) {
-                error.message += `"${cause.message}"`;
-            }
-            else {
-                error.message = `Something that is not an Error was thrown in ${hookName} (see this Error's "cause" property)`;
-            }
+            error.message =
+                cause instanceof Error
+                    ? `The following error occurred in ${hookName}: "${cause.message}"`
+                    : `Something that is not an Error was thrown in ${hookName} (see this Error's "cause" property)`;
             throw error;
         };
+        let result;
         try {
-            const result = fn(...args);
-            if (result instanceof Promise) {
-                if (hookName === "onWillStart" || hookName === "onWillUpdateProps") {
-                    const fiber = node.fiber;
-                    Promise.race([
-                        result.catch(() => { }),
-                        new Promise((resolve) => setTimeout(() => resolve(TIMEOUT), 3000)),
-                    ]).then((res) => {
-                        if (res === TIMEOUT && node.fiber === fiber && node.status <= 2) {
-                            console.warn(timeoutError);
-                        }
-                    });
-                }
-                return result.catch(onError);
-            }
-            return result;
+            result = fn(...args);
         }
         catch (cause) {
             onError(cause);
         }
+        if (!(result instanceof Promise)) {
+            return result;
+        }
+        const timeout = HOOK_TIMEOUT[hookName];
+        if (timeout) {
+            const fiber = node.fiber;
+            Promise.race([
+                result.catch(() => { }),
+                new Promise((resolve) => setTimeout(() => resolve(TIMEOUT), timeout)),
+            ]).then((res) => {
+                if (res === TIMEOUT && node.fiber === fiber && node.status <= 2) {
+                    timeoutError.message = `${hookName}'s promise hasn't resolved after ${timeout / 1000} seconds`;
+                    console.log(timeoutError);
+                }
+            });
+        }
+        return result.catch(onError);
     };
 }
 // -----------------------------------------------------------------------------
@@ -3216,6 +3243,9 @@ class TemplateSet {
             }
         }
         this.getRawTemplate = config.getTemplate;
+        this.customDirectives = config.customDirectives || {};
+        this.runtimeUtils = { ...helpers, __globals__: config.globalValues || {} };
+        this.hasGlobalValues = Boolean(config.globalValues && Object.keys(config.globalValues).length);
     }
     static registerTemplate(name, fn) {
         globalTemplates[name] = fn;
@@ -3272,7 +3302,7 @@ class TemplateSet {
             this.templates[name] = function (context, parent) {
                 return templates[name].call(this, context, parent);
             };
-            const template = templateFn(this, bdom, helpers);
+            const template = templateFn(this, bdom, this.runtimeUtils);
             this.templates[name] = template;
         }
         return this.templates[name];
@@ -3323,7 +3353,7 @@ TemplateSet.registerTemplate("__portal__", portalTemplate);
 //------------------------------------------------------------------------------
 // Misc types, constants and helpers
 //------------------------------------------------------------------------------
-const RESERVED_WORDS = "true,false,NaN,null,undefined,debugger,console,window,in,instanceof,new,function,return,eval,void,Math,RegExp,Array,Object,Date".split(",");
+const RESERVED_WORDS = "true,false,NaN,null,undefined,debugger,console,window,in,instanceof,new,function,return,eval,void,Math,RegExp,Array,Object,Date,__globals__".split(",");
 const WORD_REPLACEMENT = Object.assign(Object.create(null), {
     and: "&&",
     or: "||",
@@ -3795,6 +3825,9 @@ class CodeGenerator {
         this.dev = options.dev || false;
         this.ast = ast;
         this.templateName = options.name;
+        if (options.hasGlobalValues) {
+            this.helpers.add("__globals__");
+        }
     }
     generateCode() {
         const ast = this.ast;
@@ -4594,7 +4627,12 @@ class CodeGenerator {
      * "onClick.bind"    "onClick"        "onClick: bind(ctx, ctx['onClick'])"
      */
     formatProp(name, value) {
-        value = this.captureExpression(value);
+        if (name.endsWith(".translate")) {
+            value = toStringExpression(this.translateFn(value));
+        }
+        else {
+            value = this.captureExpression(value);
+        }
         if (name.includes(".")) {
             let [_name, suffix] = name.split(".");
             name = _name;
@@ -4603,6 +4641,7 @@ class CodeGenerator {
                     value = `(${value}).bind(this)`;
                     break;
                 case "alike":
+                case "translate":
                     break;
                 default:
                     throw new OwlError("Invalid prop suffix");
@@ -4827,29 +4866,33 @@ class CodeGenerator {
 // Parser
 // -----------------------------------------------------------------------------
 const cache = new WeakMap();
-function parse(xml) {
+function parse(xml, customDir) {
+    const ctx = {
+        inPreTag: false,
+        customDirectives: customDir,
+    };
     if (typeof xml === "string") {
         const elem = parseXML(`<t>${xml}</t>`).firstChild;
-        return _parse(elem);
+        return _parse(elem, ctx);
     }
     let ast = cache.get(xml);
     if (!ast) {
         // we clone here the xml to prevent modifying it in place
-        ast = _parse(xml.cloneNode(true));
+        ast = _parse(xml.cloneNode(true), ctx);
         cache.set(xml, ast);
     }
     return ast;
 }
-function _parse(xml) {
+function _parse(xml, ctx) {
     normalizeXML(xml);
-    const ctx = { inPreTag: false };
     return parseNode(xml, ctx) || { type: 0 /* Text */, value: "" };
 }
 function parseNode(node, ctx) {
     if (!(node instanceof Element)) {
         return parseTextCommentNode(node, ctx);
     }
-    return (parseTDebugLog(node, ctx) ||
+    return (parseTCustom(node, ctx) ||
+        parseTDebugLog(node, ctx) ||
         parseTForEach(node, ctx) ||
         parseTIf(node, ctx) ||
         parseTPortal(node, ctx) ||
@@ -4891,6 +4934,35 @@ function parseTextCommentNode(node, ctx) {
     }
     return null;
 }
+function parseTCustom(node, ctx) {
+    if (!ctx.customDirectives) {
+        return null;
+    }
+    const nodeAttrsNames = node.getAttributeNames();
+    for (let attr of nodeAttrsNames) {
+        if (attr === "t-custom" || attr === "t-custom-") {
+            throw new OwlError("Missing custom directive name with t-custom directive");
+        }
+        if (attr.startsWith("t-custom-")) {
+            const directiveName = attr.split(".")[0].slice(9);
+            const customDirective = ctx.customDirectives[directiveName];
+            if (!customDirective) {
+                throw new OwlError(`Custom directive "${directiveName}" is not defined`);
+            }
+            const value = node.getAttribute(attr);
+            const modifiers = attr.split(".").slice(1);
+            node.removeAttribute(attr);
+            try {
+                customDirective(node, value, modifiers);
+            }
+            catch (error) {
+                throw new OwlError(`Custom directive "${directiveName}" throw the following error: ${error}`);
+            }
+            return parseNode(node, ctx);
+        }
+    }
+    return null;
+}
 // -----------------------------------------------------------------------------
 // debugging
 // -----------------------------------------------------------------------------
@@ -5522,9 +5594,11 @@ function normalizeXML(el) {
     normalizeTEscTOut(el);
 }
 
-function compile(template, options = {}) {
+function compile(template, options = {
+    hasGlobalValues: false,
+}) {
     // parsing
-    const ast = parse(template);
+    const ast = parse(template, options.customDirectives);
     // some work
     const hasSafeContext = template instanceof Node
         ? !(template instanceof Element) || template.querySelector("[t-set], [t-call]") === null
@@ -5546,7 +5620,7 @@ function compile(template, options = {}) {
 }
 
 // do not modify manually. This file is generated by the release script.
-const version = "2.2.11";
+const version = "2.5.2";
 
 // -----------------------------------------------------------------------------
 //  Scheduler
@@ -5557,6 +5631,7 @@ class Scheduler {
         this.frame = 0;
         this.delayedRenders = [];
         this.cancelledNodes = new Set();
+        this.processing = false;
         this.requestAnimationFrame = Scheduler.requestAnimationFrame;
     }
     addFiber(fiber) {
@@ -5587,6 +5662,10 @@ class Scheduler {
         }
     }
     processTasks() {
+        if (this.processing) {
+            return;
+        }
+        this.processing = true;
         this.frame = 0;
         for (let node of this.cancelledNodes) {
             node._destroy();
@@ -5600,6 +5679,7 @@ class Scheduler {
                 this.tasks.delete(task);
             }
         }
+        this.processing = false;
     }
     processFiber(fiber) {
         if (fiber.root !== fiber) {
@@ -5619,7 +5699,14 @@ class Scheduler {
             if (!hasError) {
                 fiber.complete();
             }
-            this.tasks.delete(fiber);
+            // at this point, the fiber should have been applied to the DOM, so we can
+            // remove it from the task list. If it is not the case, it means that there
+            // was an error and an error handler triggered a new rendering that recycled
+            // the fiber, so in that case, we actually want to keep the fiber around,
+            // otherwise it will just be ignored.
+            if (fiber.appliedToDom) {
+                this.tasks.delete(fiber);
+            }
         }
     }
 }
@@ -5641,6 +5728,7 @@ class App extends TemplateSet {
     constructor(Root, config = {}) {
         super(config);
         this.scheduler = new Scheduler();
+        this.subRoots = new Set();
         this.root = null;
         this.name = config.name || "";
         this.Root = Root;
@@ -5659,14 +5747,44 @@ class App extends TemplateSet {
         this.props = config.props || {};
     }
     mount(target, options) {
-        App.validateTarget(target);
-        if (this.dev) {
-            validateProps(this.Root, this.props, { __owl__: { app: this } });
+        const root = this.createRoot(this.Root, { props: this.props });
+        this.root = root.node;
+        this.subRoots.delete(root.node);
+        return root.mount(target, options);
+    }
+    createRoot(Root, config = {}) {
+        const props = config.props || {};
+        // hack to make sure the sub root get the sub env if necessary. for owl 3,
+        // would be nice to rethink the initialization process to make sure that
+        // we can create a ComponentNode and give it explicitely the env, instead
+        // of looking it up in the app
+        const env = this.env;
+        if (config.env) {
+            this.env = config.env;
         }
-        const node = this.makeNode(this.Root, this.props);
-        const prom = this.mountNode(node, target, options);
-        this.root = node;
-        return prom;
+        const restore = saveCurrent();
+        const node = this.makeNode(Root, props);
+        restore();
+        if (config.env) {
+            this.env = env;
+        }
+        this.subRoots.add(node);
+        return {
+            node,
+            mount: (target, options) => {
+                App.validateTarget(target);
+                if (this.dev) {
+                    validateProps(Root, props, { __owl__: { app: this } });
+                }
+                const prom = this.mountNode(node, target, options);
+                return prom;
+            },
+            destroy: () => {
+                this.subRoots.delete(node);
+                node.destroy();
+                this.scheduler.processTasks();
+            },
+        };
     }
     makeNode(Component, props) {
         return new ComponentNode(Component, props, this, null, null);
@@ -5698,6 +5816,9 @@ class App extends TemplateSet {
     }
     destroy() {
         if (this.root) {
+            for (let subroot of this.subRoots) {
+                subroot.destroy();
+            }
             this.root.destroy();
             this.scheduler.processTasks();
         }
@@ -5969,12 +6090,14 @@ TemplateSet.prototype._compileTemplate = function _compileTemplate(name, templat
         dev: this.dev,
         translateFn: this.translateFn,
         translatableAttributes: this.translatableAttributes,
+        customDirectives: this.customDirectives,
+        hasGlobalValues: this.hasGlobalValues,
     });
 };
 
 export { App, Component, EventBus, OwlError, __info__, batched, blockDom, loadFile, markRaw, markup, mount, onError, onMounted, onPatched, onRendered, onWillDestroy, onWillPatch, onWillRender, onWillStart, onWillUnmount, onWillUpdateProps, reactive, status, toRaw, useChildSubEnv, useComponent, useEffect, useEnv, useExternalListener, useRef, useState, useSubEnv, validate, validateType, whenReady, xml };
 
 
-__info__.date = '2024-06-17T13:31:12.099Z';
-__info__.hash = 'e7f405c';
+__info__.date = '2024-12-02T15:51:07.157Z';
+__info__.hash = '1c5b6f2';
 __info__.url = 'https://github.com/odoo/owl';

package-lock.json

@@ -1,6 +1,6 @@
 {
   "name": "@odoo/owl",
-  "version": "2.2.11",
+  "version": "2.5.2",
   "lockfileVersion": 1,
   "requires": true,
   "dependencies": {

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@odoo/owl",
-  "version": "2.2.11",
+  "version": "2.5.2",
   "description": "Odoo Web Library (OWL)",
   "main": "dist/owl.cjs.js",
   "module": "dist/owl.es.js",
@@ -9,7 +9,7 @@
     "dist"
   ],
   "engines": {
-    "node": ">=12.18.3"
+    "node": ">=20.0.0"
   },
   "scripts": {
     "build:bundle": "rollup -c --failAfterWarnings",

src/common/types.ts

@@ -0,0 +1,4 @@
+export type customDirectives = Record<
+  string,
+  (node: Element, value: string, modifier: string[]) => void
+>;

src/compiler/code_generator.ts

@@ -43,6 +43,7 @@ export interface Config {
 export interface CodeGenOptions extends Config {
   hasSafeContext?: boolean;
   name?: string;
+  hasGlobalValues: boolean;
 }
 
 // using a non-html document so that <inner/outer>HTML serializes as XML instead
@@ -286,6 +287,9 @@ export class CodeGenerator {
     this.dev = options.dev || false;
     this.ast = ast;
     this.templateName = options.name;
+    if (options.hasGlobalValues) {
+      this.helpers.add("__globals__");
+    }
   }
 
   generateCode(): string {
@@ -1136,7 +1140,11 @@ export class CodeGenerator {
    * "onClick.bind"    "onClick"        "onClick: bind(ctx, ctx['onClick'])"
    */
   formatProp(name: string, value: string): string {
-    value = this.captureExpression(value);
+    if (name.endsWith(".translate")) {
+      value = toStringExpression(this.translateFn(value));
+    } else {
+      value = this.captureExpression(value);
+    }
     if (name.includes(".")) {
       let [_name, suffix] = name.split(".");
       name = _name;
@@ -1145,6 +1153,7 @@ export class CodeGenerator {
           value = `(${value}).bind(this)`;
           break;
         case "alike":
+        case "translate":
           break;
         default:
           throw new OwlError("Invalid prop suffix");

src/compiler/index.ts

@@ -1,3 +1,4 @@
+import type { customDirectives } from "../common/types";
 import type { TemplateSet } from "../runtime/template_set";
 import type { BDom } from "../runtime/blockdom";
 import { CodeGenerator, Config } from "./code_generator";
@@ -10,13 +11,17 @@ export type TemplateFunction = (app: TemplateSet, bdom: any, helpers: any) => Te
 
 interface CompileOptions extends Config {
   name?: string;
+  customDirectives?: customDirectives;
+  hasGlobalValues: boolean;
 }
 export function compile(
   template: string | Element,
-  options: CompileOptions = {}
+  options: CompileOptions = {
+    hasGlobalValues: false,
+  }
 ): TemplateFunction {
   // parsing
-  const ast = parse(template);
+  const ast = parse(template, options.customDirectives);
 
   // some work
   const hasSafeContext =

src/compiler/inline_expressions.ts

@@ -28,7 +28,7 @@ import { OwlError } from "../common/owl_error";
 //------------------------------------------------------------------------------
 
 const RESERVED_WORDS =
-  "true,false,NaN,null,undefined,debugger,console,window,in,instanceof,new,function,return,eval,void,Math,RegExp,Array,Object,Date".split(
+  "true,false,NaN,null,undefined,debugger,console,window,in,instanceof,new,function,return,eval,void,Math,RegExp,Array,Object,Date,__globals__".split(
     ","
   );
 

src/compiler/parser.ts

@@ -1,4 +1,5 @@
 import { OwlError } from "../common/owl_error";
+import type { customDirectives } from "../common/types";
 import { parseXML } from "../common/utils";
 
 // -----------------------------------------------------------------------------
@@ -198,23 +199,26 @@ export type AST =
 // -----------------------------------------------------------------------------
 const cache: WeakMap<Element, AST> = new WeakMap();
 
-export function parse(xml: string | Element): AST {
+export function parse(xml: string | Element, customDir?: customDirectives): AST {
+  const ctx = {
+    inPreTag: false,
+    customDirectives: customDir,
+  };
   if (typeof xml === "string") {
     const elem = parseXML(`<t>${xml}</t>`).firstChild as Element;
-    return _parse(elem);
+    return _parse(elem, ctx);
   }
   let ast = cache.get(xml);
   if (!ast) {
     // we clone here the xml to prevent modifying it in place
-    ast = _parse(xml.cloneNode(true) as Element);
+    ast = _parse(xml.cloneNode(true) as Element, ctx);
     cache.set(xml, ast);
   }
   return ast;
 }
 
-function _parse(xml: Element): AST {
+function _parse(xml: Element, ctx: ParsingContext): AST {
   normalizeXML(xml);
-  const ctx = { inPreTag: false };
   return parseNode(xml, ctx) || { type: ASTType.Text, value: "" };
 }
 
@@ -222,6 +226,7 @@ interface ParsingContext {
   tModelInfo?: TModelInfo | null;
   nameSpace?: string;
   inPreTag: boolean;
+  customDirectives?: customDirectives;
 }
 
 function parseNode(node: Node, ctx: ParsingContext): AST | null {
@@ -229,6 +234,7 @@ function parseNode(node: Node, ctx: ParsingContext): AST | null {
     return parseTextCommentNode(node, ctx);
   }
   return (
+    parseTCustom(node, ctx) ||
     parseTDebugLog(node, ctx) ||
     parseTForEach(node, ctx) ||
     parseTIf(node, ctx) ||
@@ -277,6 +283,37 @@ function parseTextCommentNode(node: Node, ctx: ParsingContext): AST | null {
   return null;
 }
 
+function parseTCustom(node: Element, ctx: ParsingContext): AST | null {
+  if (!ctx.customDirectives) {
+    return null;
+  }
+  const nodeAttrsNames = node.getAttributeNames();
+  for (let attr of nodeAttrsNames) {
+    if (attr === "t-custom" || attr === "t-custom-") {
+      throw new OwlError("Missing custom directive name with t-custom directive");
+    }
+    if (attr.startsWith("t-custom-")) {
+      const directiveName = attr.split(".")[0].slice(9);
+      const customDirective = ctx.customDirectives[directiveName];
+      if (!customDirective) {
+        throw new OwlError(`Custom directive "${directiveName}" is not defined`);
+      }
+      const value = node.getAttribute(attr)!;
+      const modifiers = attr.split(".").slice(1);
+      node.removeAttribute(attr);
+      try {
+        customDirective(node, value, modifiers);
+      } catch (error) {
+        throw new OwlError(
+          `Custom directive "${directiveName}" throw the following error: ${error}`
+        );
+      }
+      return parseNode(node, ctx);
+    }
+  }
+  return null;
+}
+
 // -----------------------------------------------------------------------------
 // debugging
 // -----------------------------------------------------------------------------

src/index.ts

@@ -12,5 +12,7 @@ TemplateSet.prototype._compileTemplate = function _compileTemplate(
     dev: this.dev,
     translateFn: this.translateFn,
     translatableAttributes: this.translatableAttributes,
+    customDirectives: this.customDirectives,
+    hasGlobalValues: this.hasGlobalValues,
   });
 };

src/runtime/app.ts

@@ -1,6 +1,6 @@
 import { version } from "../version";
 import { Component, ComponentConstructor, Props } from "./component";
-import { ComponentNode } from "./component_node";
+import { ComponentNode, saveCurrent } from "./component_node";
 import { nodeErrorHandlers, handleError } from "./error_handling";
 import { OwlError } from "../common/owl_error";
 import { Fiber, RootFiber, MountOptions } from "./fibers";
@@ -16,10 +16,13 @@ export interface Env {
   [key: string]: any;
 }
 
-export interface AppConfig<P, E> extends TemplateSetConfig {
-  name?: string;
+export interface RootConfig<P, E> {
   props?: P;
   env?: E;
+}
+
+export interface AppConfig<P, E> extends TemplateSetConfig, RootConfig<P, E> {
+  name?: string;
   test?: boolean;
   warnIfNoStaticProps?: boolean;
 }
@@ -49,6 +52,12 @@ declare global {
   }
 }
 
+interface Root<P extends Props, E> {
+  node: ComponentNode<P, E>;
+  mount(target: HTMLElement | ShadowRoot, options?: MountOptions): Promise<Component<P, E>>;
+  destroy(): void;
+}
+
 window.__OWL_DEVTOOLS__ ||= { apps, Fiber, RootFiber, toRaw, reactive };
 
 export class App<
@@ -65,6 +74,7 @@ export class App<
   props: P;
   env: E;
   scheduler = new Scheduler();
+  subRoots: Set<ComponentNode> = new Set();
   root: ComponentNode<P, E> | null = null;
   warnIfNoStaticProps: boolean;
 
@@ -91,14 +101,49 @@ export class App<
     target: HTMLElement | ShadowRoot,
     options?: MountOptions
   ): Promise<Component<P, E> & InstanceType<T>> {
-    App.validateTarget(target);
-    if (this.dev) {
-      validateProps(this.Root, this.props, { __owl__: { app: this } });
+    const root = this.createRoot(this.Root, { props: this.props });
+    this.root = root.node;
+    this.subRoots.delete(root.node);
+    return root.mount(target, options) as any;
+  }
+
+  createRoot<Props extends object, SubEnv = any>(
+    Root: ComponentConstructor<Props, E>,
+    config: RootConfig<Props, SubEnv> = {}
+  ): Root<Props, SubEnv> {
+    const props = config.props || ({} as Props);
+    // hack to make sure the sub root get the sub env if necessary. for owl 3,
+    // would be nice to rethink the initialization process to make sure that
+    // we can create a ComponentNode and give it explicitely the env, instead
+    // of looking it up in the app
+    const env = this.env;
+    if (config.env) {
+      this.env = config.env as any;
     }
-    const node = this.makeNode(this.Root, this.props);
-    const prom = this.mountNode(node, target, options);
-    this.root = node;
-    return prom;
+
+    const restore = saveCurrent();
+    const node = this.makeNode(Root, props);
+    restore();
+    if (config.env) {
+      this.env = env;
+    }
+    this.subRoots.add(node);
+    return {
+      node,
+      mount: (target: HTMLElement | ShadowRoot, options?: MountOptions) => {
+        App.validateTarget(target);
+        if (this.dev) {
+          validateProps(Root, props, { __owl__: { app: this } });
+        }
+        const prom = this.mountNode(node, target, options);
+        return prom;
+      },
+      destroy: () => {
+        this.subRoots.delete(node);
+        node.destroy();
+        this.scheduler.processTasks();
+      },
+    };
   }
 
   makeNode(Component: ComponentConstructor, props: any): ComponentNode {
@@ -134,6 +179,9 @@ export class App<
 
   destroy() {
     if (this.root) {
+      for (let subroot of this.subRoots) {
+        subroot.destroy();
+      }
       this.root.destroy();
       this.scheduler.processTasks();
     }

src/runtime/component_node.ts

@@ -10,6 +10,13 @@ import { batched, Callback } from "./utils";
 
 let currentNode: ComponentNode | null = null;
 
+export function saveCurrent() {
+  let n = currentNode;
+  return () => {
+    currentNode = n;
+  };
+}
+
 export function getCurrent(): ComponentNode {
   if (!currentNode) {
     throw new OwlError("No active component (a hook function should only be called in 'setup')");

src/runtime/fibers.ts

@@ -30,6 +30,13 @@ export function makeRootFiber(node: ComponentNode): Fiber {
       fibersInError.delete(current);
       fibersInError.delete(root);
       current.appliedToDom = false;
+      if (current instanceof RootFiber) {
+        // it is possible that this fiber is a fiber that crashed while being
+        // mounted, so the mounted list is possibly corrupted. We restore it to
+        // its normal initial state (which is empty list or a list with a mount
+        // fiber.
+        current.mounted = current instanceof MountFiber ? [current] : [];
+      }
     }
     return current;
   }
@@ -152,6 +159,7 @@ export class RootFiber extends Fiber {
     const node = this.node;
     this.locked = true;
     let current: Fiber | undefined = undefined;
+    let mountedFibers = this.mounted;
     try {
       // Step 1: calling all willPatch lifecycle hooks
       for (current of this.willPatch) {
@@ -173,7 +181,6 @@ export class RootFiber extends Fiber {
       this.locked = false;
 
       // Step 4: calling all mounted lifecycle hooks
-      let mountedFibers = this.mounted;
       while ((current = mountedFibers.pop())) {
         current = current;
         if (current.appliedToDom) {
@@ -194,6 +201,15 @@ export class RootFiber extends Fiber {
         }
       }
     } catch (e) {
+      // if mountedFibers is not empty, this means that a crash occured while
+      // calling the mounted hooks of some component. So, there may still be
+      // some component that have been mounted, but for which the mounted hooks
+      // have not been called. Here, we remove the willUnmount hooks for these
+      // specific component to prevent a worse situation (willUnmount being
+      // called even though mounted has not been called)
+      for (let fiber of mountedFibers) {
+        fiber.node.willUnmount = [];
+      }
       this.locked = false;
       node.app.handleError({ fiber: current || this, error: e });
     }

src/runtime/lifecycle_hooks.ts

@@ -3,42 +3,50 @@ import { nodeErrorHandlers } from "./error_handling";
 import { OwlError } from "../common/owl_error";
 
 const TIMEOUT = Symbol("timeout");
+const HOOK_TIMEOUT: { [key: string]: number } = {
+  onWillStart: 3000,
+  onWillUpdateProps: 3000,
+};
 function wrapError(fn: (...args: any[]) => any, hookName: string) {
-  const error = new OwlError(`The following error occurred in ${hookName}: `) as Error & {
+  const error = new OwlError() as Error & {
     cause: any;
   };
-  const timeoutError = new OwlError(`${hookName}'s promise hasn't resolved after 3 seconds`);
+  const timeoutError = new OwlError();
   const node = getCurrent();
   return (...args: any[]) => {
     const onError = (cause: any) => {
       error.cause = cause;
-      if (cause instanceof Error) {
-        error.message += `"${cause.message}"`;
-      } else {
-        error.message = `Something that is not an Error was thrown in ${hookName} (see this Error's "cause" property)`;
-      }
+      error.message =
+        cause instanceof Error
+          ? `The following error occurred in ${hookName}: "${cause.message}"`
+          : `Something that is not an Error was thrown in ${hookName} (see this Error's "cause" property)`;
       throw error;
     };
+    let result;
     try {
-      const result = fn(...args);
-      if (result instanceof Promise) {
-        if (hookName === "onWillStart" || hookName === "onWillUpdateProps") {
-          const fiber = node.fiber;
-          Promise.race([
-            result.catch(() => {}),
-            new Promise((resolve) => setTimeout(() => resolve(TIMEOUT), 3000)),
-          ]).then((res) => {
-            if (res === TIMEOUT && node.fiber === fiber && node.status <= 2) {
-              console.warn(timeoutError);
-            }
-          });
-        }
-        return result.catch(onError);
-      }
-      return result;
+      result = fn(...args);
     } catch (cause) {
       onError(cause);
     }
+    if (!(result instanceof Promise)) {
+      return result;
+    }
+    const timeout = HOOK_TIMEOUT[hookName];
+    if (timeout) {
+      const fiber = node.fiber;
+      Promise.race([
+        result.catch(() => {}),
+        new Promise((resolve) => setTimeout(() => resolve(TIMEOUT), timeout)),
+      ]).then((res) => {
+        if (res === TIMEOUT && node.fiber === fiber && node.status <= 2) {
+          timeoutError.message = `${hookName}'s promise hasn't resolved after ${
+            timeout / 1000
+          } seconds`;
+          console.log(timeoutError);
+        }
+      });
+    }
+    return result.catch(onError);
   };
 }
 

src/runtime/scheduler.ts

@@ -16,6 +16,7 @@ export class Scheduler {
   frame: number = 0;
   delayedRenders: Fiber[] = [];
   cancelledNodes: Set<ComponentNode> = new Set();
+  processing = false;
 
   constructor() {
     this.requestAnimationFrame = Scheduler.requestAnimationFrame;
@@ -53,6 +54,10 @@ export class Scheduler {
   }
 
   processTasks() {
+    if (this.processing) {
+      return;
+    }
+    this.processing = true;
     this.frame = 0;
     for (let node of this.cancelledNodes) {
       node._destroy();
@@ -66,6 +71,7 @@ export class Scheduler {
         this.tasks.delete(task);
       }
     }
+    this.processing = false;
   }
 
   processFiber(fiber: RootFiber) {
@@ -87,7 +93,14 @@ export class Scheduler {
       if (!hasError) {
         fiber.complete();
       }
-      this.tasks.delete(fiber);
+      // at this point, the fiber should have been applied to the DOM, so we can
+      // remove it from the task list. If it is not the case, it means that there
+      // was an error and an error handler triggered a new rendering that recycled
+      // the fiber, so in that case, we actually want to keep the fiber around,
+      // otherwise it will just be ignored.
+      if (fiber.appliedToDom) {
+        this.tasks.delete(fiber);
+      }
     }
   }
 }

src/runtime/template_set.ts

@@ -5,6 +5,7 @@ import { Portal, portalTemplate } from "./portal";
 import { helpers } from "./template_helpers";
 import { OwlError } from "../common/owl_error";
 import { parseXML } from "../common/utils";
+import type { customDirectives } from "../common/types";
 
 const bdom = { text, createBlock, list, multi, html, toggler, comment };
 
@@ -14,6 +15,8 @@ export interface TemplateSetConfig {
   translateFn?: (s: string) => string;
   templates?: string | Document | Record<string, string>;
   getTemplate?: (s: string) => Element | Function | string | void;
+  customDirectives?: customDirectives;
+  globalValues?: object;
 }
 
 export class TemplateSet {
@@ -27,6 +30,9 @@ export class TemplateSet {
   translateFn?: (s: string) => string;
   translatableAttributes?: string[];
   Portal = Portal;
+  customDirectives: customDirectives;
+  runtimeUtils: object;
+  hasGlobalValues: boolean;
 
   constructor(config: TemplateSetConfig = {}) {
     this.dev = config.dev || false;
@@ -42,6 +48,9 @@ export class TemplateSet {
       }
     }
     this.getRawTemplate = config.getTemplate;
+    this.customDirectives = config.customDirectives || {};
+    this.runtimeUtils = { ...helpers, __globals__: config.globalValues || {} };
+    this.hasGlobalValues = Boolean(config.globalValues && Object.keys(config.globalValues).length);
   }
 
   addTemplate(name: string, template: string | Element) {
@@ -97,7 +106,7 @@ export class TemplateSet {
       this.templates[name] = function (context, parent) {
         return templates[name].call(this, context, parent);
       };
-      const template = templateFn(this, bdom, helpers);
+      const template = templateFn(this, bdom, this.runtimeUtils);
       this.templates[name] = template;
     }
     return this.templates[name];

src/version.ts

@@ -1,2 +1,2 @@
 // do not modify manually. This file is generated by the release script.
-export const version = "2.2.11";
+export const version = "2.5.2";

tests/app/__snapshots__/app.test.ts.snap

@@ -43,6 +43,48 @@ exports[`app app: clear scheduler tasks and destroy cancelled nodes immediately
 }"
 `;
 
+exports[`app can add functions to the bdom 1`] = `
+"function anonymous(app, bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, comment } = bdom;
+  let { __globals__ } = helpers;
+  
+  let block1 = createBlock(\`<div class=\\"my-div\\" block-handler-0=\\"click\\"/>\`);
+  
+  return function template(ctx, node, key = \\"\\") {
+    let hdlr1 = [()=>__globals__.plop('click'), ctx];
+    return block1([hdlr1]);
+  }
+}"
+`;
+
+exports[`app can call processTask twice in a row without crashing 1`] = `
+"function anonymous(app, bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, comment } = bdom;
+  const comp1 = app.createComponent(\`Child\`, true, false, false, []);
+  
+  return function template(ctx, node, key = \\"\\") {
+    const b2 = text(\`parent\`);
+    const b3 = comp1({}, key + \`__1\`, node, this, null);
+    return multi([b2, b3]);
+  }
+}"
+`;
+
+exports[`app can call processTask twice in a row without crashing 2`] = `
+"function anonymous(app, bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, comment } = bdom;
+  
+  let block1 = createBlock(\`<div/>\`);
+  
+  return function template(ctx, node, key = \\"\\") {
+    return block1();
+  }
+}"
+`;
+
 exports[`app can configure an app with props 1`] = `
 "function anonymous(app, bdom, helpers
 ) {

tests/app/__snapshots__/sub_root.test.ts.snap

@@ -0,0 +1,210 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`destroy a subroot while another component is mounted in main app 1`] = `
+"function anonymous(app, bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, comment } = bdom;
+  const comp1 = app.createComponent(\`ChildB\`, true, false, false, []);
+  const comp2 = app.createComponent(\`ChildA\`, true, false, false, []);
+  
+  return function template(ctx, node, key = \\"\\") {
+    let b2, b3;
+    if (ctx['state'].flag) {
+      b2 = comp1({}, key + \`__1\`, node, this, null);
+    } else {
+      b3 = comp2({}, key + \`__2\`, node, this, null);
+    }
+    return multi([b2, b3]);
+  }
+}"
+`;
+
+exports[`destroy a subroot while another component is mounted in main app 2`] = `
+"function anonymous(app, bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, comment } = bdom;
+  
+  let block3 = createBlock(\`<div block-ref=\\"0\\"/>\`);
+  
+  return function template(ctx, node, key = \\"\\") {
+    const b2 = text(\`a\`);
+    let ref1 = (el) => this.__owl__.setRef((\`elem\`), el);
+    const b3 = block3([ref1]);
+    return multi([b2, b3]);
+  }
+}"
+`;
+
+exports[`destroy a subroot while another component is mounted in main app 3`] = `
+"function anonymous(app, bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, comment } = bdom;
+  
+  return function template(ctx, node, key = \\"\\") {
+    return text(\`c\`);
+  }
+}"
+`;
+
+exports[`destroy a subroot while another component is mounted in main app 4`] = `
+"function anonymous(app, bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, comment } = bdom;
+  
+  return function template(ctx, node, key = \\"\\") {
+    return text(\`b\`);
+  }
+}"
+`;
+
+exports[`subroot by default, env is the same in sub root 1`] = `
+"function anonymous(app, bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, comment } = bdom;
+  
+  let block1 = createBlock(\`<div>main app</div>\`);
+  
+  return function template(ctx, node, key = \\"\\") {
+    return block1();
+  }
+}"
+`;
+
+exports[`subroot by default, env is the same in sub root 2`] = `
+"function anonymous(app, bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, comment } = bdom;
+  
+  let block1 = createBlock(\`<div>sub root</div>\`);
+  
+  return function template(ctx, node, key = \\"\\") {
+    return block1();
+  }
+}"
+`;
+
+exports[`subroot can create a root in a setup function, then use a hook 1`] = `
+"function anonymous(app, bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, comment } = bdom;
+  
+  return function template(ctx, node, key = \\"\\") {
+    return text(\`a\`);
+  }
+}"
+`;
+
+exports[`subroot can create a root in a setup function, then use a hook 2`] = `
+"function anonymous(app, bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, comment } = bdom;
+  
+  return function template(ctx, node, key = \\"\\") {
+    return text(\`c\`);
+  }
+}"
+`;
+
+exports[`subroot can mount subroot 1`] = `
+"function anonymous(app, bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, comment } = bdom;
+  
+  let block1 = createBlock(\`<div>main app</div>\`);
+  
+  return function template(ctx, node, key = \\"\\") {
+    return block1();
+  }
+}"
+`;
+
+exports[`subroot can mount subroot 2`] = `
+"function anonymous(app, bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, comment } = bdom;
+  
+  let block1 = createBlock(\`<div>sub root</div>\`);
+  
+  return function template(ctx, node, key = \\"\\") {
+    return block1();
+  }
+}"
+`;
+
+exports[`subroot can mount subroot inside own dom 1`] = `
+"function anonymous(app, bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, comment } = bdom;
+  
+  let block1 = createBlock(\`<div>main app</div>\`);
+  
+  return function template(ctx, node, key = \\"\\") {
+    return block1();
+  }
+}"
+`;
+
+exports[`subroot can mount subroot inside own dom 2`] = `
+"function anonymous(app, bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, comment } = bdom;
+  
+  let block1 = createBlock(\`<div>sub root</div>\`);
+  
+  return function template(ctx, node, key = \\"\\") {
+    return block1();
+  }
+}"
+`;
+
+exports[`subroot env can be specified for sub roots 1`] = `
+"function anonymous(app, bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, comment } = bdom;
+  
+  let block1 = createBlock(\`<div>main app</div>\`);
+  
+  return function template(ctx, node, key = \\"\\") {
+    return block1();
+  }
+}"
+`;
+
+exports[`subroot env can be specified for sub roots 2`] = `
+"function anonymous(app, bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, comment } = bdom;
+  
+  let block1 = createBlock(\`<div>sub root</div>\`);
+  
+  return function template(ctx, node, key = \\"\\") {
+    return block1();
+  }
+}"
+`;
+
+exports[`subroot subcomponents can be destroyed, and it properly cleanup the subroots 1`] = `
+"function anonymous(app, bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, comment } = bdom;
+  
+  let block1 = createBlock(\`<div>main app</div>\`);
+  
+  return function template(ctx, node, key = \\"\\") {
+    return block1();
+  }
+}"
+`;
+
+exports[`subroot subcomponents can be destroyed, and it properly cleanup the subroots 2`] = `
+"function anonymous(app, bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, comment } = bdom;
+  
+  let block1 = createBlock(\`<div>sub root</div>\`);
+  
+  return function template(ctx, node, key = \\"\\") {
+    return block1();
+  }
+}"
+`;

tests/app/app.test.ts

@@ -1,4 +1,4 @@
-import { App, Component, mount, onWillStart, useState, xml } from "../../src";
+import { App, Component, mount, onWillPatch, onWillStart, useState, xml } from "../../src";
 import { status } from "../../src/runtime/status";
 import {
   makeTestFixture,
@@ -184,4 +184,39 @@ describe("app", () => {
     expect(Object.keys(app.templates)).toEqual(["hello"]);
     expect(Object.keys(app.rawTemplates)).toEqual(["hello", "world"]);
   });
+
+  test("can call processTask twice in a row without crashing", async () => {
+    class Child extends Component {
+      static template = xml`<div/>`;
+      setup() {
+        onWillPatch(() => app.scheduler.processTasks());
+      }
+    }
+    class SomeComponent extends Component {
+      static template = xml`parent<Child/>`;
+      static components = { Child };
+    }
+
+    const app = new App(SomeComponent);
+    await app.mount(fixture);
+    expect(fixture.innerHTML).toBe("parent<div></div>");
+  });
+
+  test("can add functions to the bdom", async () => {
+    const steps: string[] = [];
+    class SomeComponent extends Component {
+      static template = xml`<div t-on-click="() => __globals__.plop('click')" class="my-div"/>`;
+    }
+    const app = new App(SomeComponent, {
+      globalValues: {
+        plop: (string: any) => {
+          steps.push(string);
+        },
+      },
+    });
+    await app.mount(fixture);
+    expect(fixture.innerHTML).toBe(`<div class="my-div"></div>`);
+    fixture.querySelector("div")!.click();
+    expect(steps).toEqual(["click"]);
+  });
 });

tests/app/sub_root.test.ts

@@ -0,0 +1,176 @@
+import { App, Component, onMounted, onWillDestroy, useRef, useState, xml } from "../../src";
+import { status } from "../../src/runtime/status";
+import { makeTestFixture, nextTick, snapshotEverything } from "../helpers";
+
+let fixture: HTMLElement;
+
+snapshotEverything();
+
+beforeEach(() => {
+  fixture = makeTestFixture();
+});
+
+class SomeComponent extends Component {
+  static template = xml`<div>main app</div>`;
+}
+
+class SubComponent extends Component {
+  static template = xml`<div>sub root</div>`;
+}
+
+describe("subroot", () => {
+  test("can mount subroot", async () => {
+    const app = new App(SomeComponent);
+    const comp = await app.mount(fixture);
+    expect(fixture.innerHTML).toBe("<div>main app</div>");
+    const subRoot = app.createRoot(SubComponent);
+    const subcomp = await subRoot.mount(fixture);
+    expect(fixture.innerHTML).toBe("<div>main app</div><div>sub root</div>");
+
+    app.destroy();
+    expect(fixture.innerHTML).toBe("");
+    expect(status(comp)).toBe("destroyed");
+    expect(status(subcomp)).toBe("destroyed");
+  });
+
+  test("can mount subroot inside own dom", async () => {
+    const app = new App(SomeComponent);
+    const comp = await app.mount(fixture);
+    expect(fixture.innerHTML).toBe("<div>main app</div>");
+    const subRoot = app.createRoot(SubComponent);
+    const subcomp = await subRoot.mount(fixture.querySelector("div")!);
+    expect(fixture.innerHTML).toBe("<div>main app<div>sub root</div></div>");
+
+    app.destroy();
+    expect(fixture.innerHTML).toBe("");
+    expect(status(comp)).toBe("destroyed");
+    expect(status(subcomp)).toBe("destroyed");
+  });
+
+  test("by default, env is the same in sub root", async () => {
+    let env, subenv;
+    class SC extends SomeComponent {
+      setup() {
+        env = this.env;
+      }
+    }
+    class Sub extends SubComponent {
+      setup() {
+        subenv = this.env;
+      }
+    }
+
+    const app = new App(SC);
+    await app.mount(fixture);
+    const subRoot = app.createRoot(Sub);
+    await subRoot.mount(fixture);
+
+    expect(env).toBeDefined();
+    expect(subenv).toBeDefined();
+    expect(env).toBe(subenv);
+  });
+
+  test("env can be specified for sub roots", async () => {
+    const env1 = { env1: true };
+    const env2 = {};
+    let someComponentEnv: any, subComponentEnv: any;
+    class SC extends SomeComponent {
+      setup() {
+        someComponentEnv = this.env;
+      }
+    }
+    class Sub extends SubComponent {
+      setup() {
+        subComponentEnv = this.env;
+      }
+    }
+
+    const app = new App(SC, { env: env1 });
+    await app.mount(fixture);
+    const subRoot = app.createRoot(Sub, { env: env2 });
+    await subRoot.mount(fixture);
+
+    // because env is different in app => it is given a sub object, frozen and all
+    // not sure it is a good idea, but it's the way owl 2 works. maybe we should
+    // avoid doing anything with the main env and let user code do it if they
+    // want. in that case, we can change the test here to assert that they are equal
+    expect(someComponentEnv).not.toBe(env1);
+    expect(someComponentEnv!.env1).toBe(true);
+    expect(subComponentEnv).toBe(env2);
+  });
+
+  test("subcomponents can be destroyed, and it properly cleanup the subroots", async () => {
+    const app = new App(SomeComponent);
+    const comp = await app.mount(fixture);
+    expect(fixture.innerHTML).toBe("<div>main app</div>");
+    const root = app.createRoot(SubComponent);
+    const subcomp = await root.mount(fixture.querySelector("div")!);
+    expect(fixture.innerHTML).toBe("<div>main app<div>sub root</div></div>");
+
+    root.destroy();
+    expect(fixture.innerHTML).toBe("<div>main app</div>");
+    expect(status(comp)).not.toBe("destroyed");
+    expect(status(subcomp)).toBe("destroyed");
+  });
+
+  test("can create a root in a setup function, then use a hook", async () => {
+    class C extends Component {
+      static template = xml`c`;
+    }
+
+    class A extends Component {
+      static template = xml`a`;
+      state: any;
+      setup() {
+        app.createRoot(C);
+        this.state = useState({ value: 1 });
+      }
+    }
+
+    const app = new App(A);
+    await app.mount(fixture);
+    expect(fixture.innerHTML).toBe("a");
+  });
+});
+
+test("destroy a subroot while another component is mounted in main app", async () => {
+  class C extends Component {
+    static template = xml`c`;
+  }
+
+  class ChildA extends Component {
+    static template = xml`a<div t-ref="elem"></div>`;
+    ref: any;
+    setup() {
+      this.ref = useRef("elem");
+      let root = app.createRoot(C);
+      onMounted(() => {
+        root.mount(this.ref.el);
+      });
+      onWillDestroy(() => {
+        root.destroy();
+      });
+    }
+  }
+  class ChildB extends Component {
+    static template = xml`b`;
+  }
+
+  class SomeComponent extends Component {
+    static template = xml`
+        <t t-if="state.flag"><ChildB/></t>
+        <t t-else=""><ChildA/></t>
+        `;
+    static components = { ChildA, ChildB };
+    state = useState({ flag: false });
+  }
+
+  const app = new App(SomeComponent);
+  const comp = await app.mount(fixture);
+  expect(fixture.innerHTML).toBe("a<div></div>");
+  await nextTick();
+  expect(fixture.innerHTML).toBe("a<div>c</div>");
+  comp.state.flag = true;
+  await nextTick();
+  expect(fixture.innerHTML).toBe("b");
+});

tests/compiler/__snapshots__/t_custom.test.ts.snap

@@ -0,0 +1,29 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`t-custom can use t-custom directive on a node 1`] = `
+"function anonymous(app, bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, comment } = bdom;
+  
+  let block1 = createBlock(\`<div class=\\"my-div\\" block-handler-0=\\"click\\"/>\`);
+  
+  return function template(ctx, node, key = \\"\\") {
+    let hdlr1 = [ctx['click'], ctx];
+    return block1([hdlr1]);
+  }
+}"
+`;
+
+exports[`t-custom can use t-custom directive with modifiers on a node 1`] = `
+"function anonymous(app, bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, comment } = bdom;
+  
+  let block1 = createBlock(\`<div class=\\"my-div\\" block-handler-0=\\"click\\"/>\`);
+  
+  return function template(ctx, node, key = \\"\\") {
+    let hdlr1 = [ctx['click'], ctx];
+    return block1([hdlr1]);
+  }
+}"
+`;

tests/compiler/t_custom.test.ts

@@ -0,0 +1,57 @@
+import { App, Component, xml } from "../../src";
+import { makeTestFixture, snapshotEverything } from "../helpers";
+
+let fixture: HTMLElement;
+
+snapshotEverything();
+
+beforeEach(() => {
+  fixture = makeTestFixture();
+});
+
+describe("t-custom", () => {
+  test("can use t-custom directive on a node", async () => {
+    const steps: string[] = [];
+    class SomeComponent extends Component {
+      static template = xml`<div t-custom-plop="click" class="my-div"/>`;
+      click() {
+        steps.push("clicked");
+      }
+    }
+    const app = new App(SomeComponent, {
+      customDirectives: {
+        plop: (node, value) => {
+          node.setAttribute("t-on-click", value);
+        },
+      },
+    });
+    await app.mount(fixture);
+    expect(fixture.innerHTML).toBe(`<div class="my-div"></div>`);
+    fixture.querySelector("div")!.click();
+    expect(steps).toEqual(["clicked"]);
+  });
+
+  test("can use t-custom directive with modifiers on a node", async () => {
+    const steps: string[] = [];
+    class SomeComponent extends Component {
+      static template = xml`<div t-custom-plop.mouse.stop="click" class="my-div"/>`;
+      click() {
+        steps.push("clicked");
+      }
+    }
+    const app = new App(SomeComponent, {
+      customDirectives: {
+        plop: (node, value, modifiers) => {
+          node.setAttribute("t-on-click", value);
+          for (let mod of modifiers) {
+            steps.push(mod);
+          }
+        },
+      },
+    });
+    await app.mount(fixture);
+    expect(fixture.innerHTML).toBe(`<div class="my-div"></div>`);
+    fixture.querySelector("div")!.click();
+    expect(steps).toEqual(["mouse", "stop", "clicked"]);
+  });
+});

tests/compiler/validation.test.ts

@@ -48,7 +48,7 @@ describe("basic validation", () => {
   test("compilation error", () => {
     const template = `<div t-att-class="a b">test</div>`;
     expect(() => renderToString(template))
-      .toThrow(`Failed to compile anonymous template: Unexpected identifier
+      .toThrow(`Failed to compile anonymous template: Unexpected identifier 'ctx'
 
 generated code:
 function(app, bdom, helpers) {

tests/components/__snapshots__/basics.test.ts.snap

@@ -97,6 +97,19 @@ exports[`basics a component cannot be mounted in a detached node (even if node i
 }"
 `;
 
+exports[`basics a component cannot be mounted in a detached node 1`] = `
+"function anonymous(app, bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, comment } = bdom;
+  
+  let block1 = createBlock(\`<div/>\`);
+  
+  return function template(ctx, node, key = \\"\\") {
+    return block1();
+  }
+}"
+`;
+
 exports[`basics a component inside a component 1`] = `
 "function anonymous(app, bdom, helpers
 ) {
@@ -261,6 +274,19 @@ exports[`basics can mount a simple component with props 1`] = `
 }"
 `;
 
+exports[`basics cannot mount on a documentFragment 1`] = `
+"function anonymous(app, bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, comment } = bdom;
+  
+  let block1 = createBlock(\`<div>content</div>\`);
+  
+  return function template(ctx, node, key = \\"\\") {
+    return block1();
+  }
+}"
+`;
+
 exports[`basics child can be updated 1`] = `
 "function anonymous(app, bdom, helpers
 ) {
@@ -1002,6 +1028,19 @@ exports[`basics three level of components with collapsing root nodes 3`] = `
 }"
 `;
 
+exports[`basics throws if mounting on target=null 1`] = `
+"function anonymous(app, bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, comment } = bdom;
+  
+  let block1 = createBlock(\`<span>simple vnode</span>\`);
+  
+  return function template(ctx, node, key = \\"\\") {
+    return block1();
+  }
+}"
+`;
+
 exports[`basics two child components 1`] = `
 "function anonymous(app, bdom, helpers
 ) {

tests/components/__snapshots__/error_handling.test.ts.snap

@@ -320,6 +320,50 @@ exports[`can catch errors can catch an error in a component render function 3`]
 }"
 `;
 
+exports[`can catch errors can catch an error in onmounted 1`] = `
+"function anonymous(app, bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, comment } = bdom;
+  const comp1 = app.createComponent(null, false, false, false, []);
+  
+  return function template(ctx, node, key = \\"\\") {
+    let b2, b3;
+    b2 = text(\`Main\`);
+    if (ctx['state'].ok) {
+      const Comp1 = ctx['component'];
+      b3 = toggler(Comp1, comp1({}, (Comp1).name + key + \`__1\`, node, this, Comp1));
+    }
+    return multi([b2, b3]);
+  }
+}"
+`;
+
+exports[`can catch errors can catch an error in onmounted 3`] = `
+"function anonymous(app, bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, comment } = bdom;
+  
+  let block1 = createBlock(\`<div>Error!!!</div>\`);
+  
+  return function template(ctx, node, key = \\"\\") {
+    return block1();
+  }
+}"
+`;
+
+exports[`can catch errors can catch an error in onmounted 4`] = `
+"function anonymous(app, bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, comment } = bdom;
+  
+  let block1 = createBlock(\`<div>perfect</div>\`);
+  
+  return function template(ctx, node, key = \\"\\") {
+    return block1();
+  }
+}"
+`;
+
 exports[`can catch errors can catch an error in the constructor call of a component render function 1`] = `
 "function anonymous(app, bdom, helpers
 ) {
@@ -1147,6 +1191,135 @@ exports[`can catch errors error in mounted on a component with a sibling (proper
 }"
 `;
 
+exports[`can catch errors error in onMounted, graceful recovery 1`] = `
+"function anonymous(app, bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, comment } = bdom;
+  const comp1 = app.createComponent(null, false, false, false, []);
+  
+  return function template(ctx, node, key = \\"\\") {
+    const Comp1 = ctx['component'];
+    return toggler(Comp1, comp1({}, (Comp1).name + key + \`__1\`, node, this, Comp1));
+  }
+}"
+`;
+
+exports[`can catch errors error in onMounted, graceful recovery 2`] = `
+"function anonymous(app, bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, comment } = bdom;
+  const comp1 = app.createComponent(\`Child\`, true, false, false, []);
+  const comp2 = app.createComponent(\`Boom\`, true, false, false, []);
+  
+  return function template(ctx, node, key = \\"\\") {
+    const b2 = text(\`parent\`);
+    const b3 = comp1({}, key + \`__1\`, node, this, null);
+    const b4 = comp2({}, key + \`__2\`, node, this, null);
+    return multi([b2, b3, b4]);
+  }
+}"
+`;
+
+exports[`can catch errors error in onMounted, graceful recovery 3`] = `
+"function anonymous(app, bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, comment } = bdom;
+  
+  return function template(ctx, node, key = \\"\\") {
+    return text(\`abc\`);
+  }
+}"
+`;
+
+exports[`can catch errors error in onMounted, graceful recovery 4`] = `
+"function anonymous(app, bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, comment } = bdom;
+  
+  return function template(ctx, node, key = \\"\\") {
+    return text(\`boom\`);
+  }
+}"
+`;
+
+exports[`can catch errors error in onMounted, graceful recovery 5`] = `
+"function anonymous(app, bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, comment } = bdom;
+  
+  return function template(ctx, node, key = \\"\\") {
+    return text(\`def\`);
+  }
+}"
+`;
+
+exports[`can catch errors error in onMounted, graceful recovery, variation 1`] = `
+"function anonymous(app, bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, comment } = bdom;
+  const comp1 = app.createComponent(null, false, false, false, []);
+  
+  return function template(ctx, node, key = \\"\\") {
+    let b2, b3;
+    b2 = text(\`R\`);
+    if (ctx['state'].gogogo) {
+      const Comp1 = ctx['component'];
+      b3 = toggler(Comp1, comp1({}, (Comp1).name + key + \`__1\`, node, this, Comp1));
+    }
+    return multi([b2, b3]);
+  }
+}"
+`;
+
+exports[`can catch errors error in onMounted, graceful recovery, variation 3`] = `
+"function anonymous(app, bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, comment } = bdom;
+  const comp1 = app.createComponent(\`Child\`, true, false, false, []);
+  const comp2 = app.createComponent(\`Boom\`, true, false, false, []);
+  
+  return function template(ctx, node, key = \\"\\") {
+    const b2 = text(\`parent\`);
+    const b3 = comp1({}, key + \`__1\`, node, this, null);
+    const b4 = comp2({}, key + \`__2\`, node, this, null);
+    return multi([b2, b3, b4]);
+  }
+}"
+`;
+
+exports[`can catch errors error in onMounted, graceful recovery, variation 4`] = `
+"function anonymous(app, bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, comment } = bdom;
+  
+  return function template(ctx, node, key = \\"\\") {
+    return text(\`abc\`);
+  }
+}"
+`;
+
+exports[`can catch errors error in onMounted, graceful recovery, variation 5`] = `
+"function anonymous(app, bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, comment } = bdom;
+  
+  return function template(ctx, node, key = \\"\\") {
+    return text(\`boom\`);
+  }
+}"
+`;
+
+exports[`can catch errors error in onMounted, graceful recovery, variation 6`] = `
+"function anonymous(app, bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, comment } = bdom;
+  
+  return function template(ctx, node, key = \\"\\") {
+    return text(\`def\`);
+  }
+}"
+`;
+
 exports[`can catch errors onError in class inheritance is called if rethrown 1`] = `
 "function anonymous(app, bdom, helpers
 ) {

tests/components/__snapshots__/lifecycle.test.ts.snap

@@ -683,7 +683,7 @@ exports[`lifecycle hooks sub widget (inside sub node): hooks are correctly calle
 }"
 `;
 
-exports[`lifecycle hooks timeout in onWillStart doesn't emit a warning if app is destroyed 1`] = `
+exports[`lifecycle hooks timeout in onWillStart doesn't emit a console log if app is destroyed 1`] = `
 "function anonymous(app, bdom, helpers
 ) {
   let { text, createBlock, list, multi, html, toggler, comment } = bdom;
@@ -696,7 +696,7 @@ exports[`lifecycle hooks timeout in onWillStart doesn't emit a warning if app is
 }"
 `;
 
-exports[`lifecycle hooks timeout in onWillStart emits a warning 1`] = `
+exports[`lifecycle hooks timeout in onWillStart emits a console log 1`] = `
 "function anonymous(app, bdom, helpers
 ) {
   let { text, createBlock, list, multi, html, toggler, comment } = bdom;
@@ -709,7 +709,7 @@ exports[`lifecycle hooks timeout in onWillStart emits a warning 1`] = `
 }"
 `;
 
-exports[`lifecycle hooks timeout in onWillUpdateProps emits a warning 1`] = `
+exports[`lifecycle hooks timeout in onWillUpdateProps emits a console log 1`] = `
 "function anonymous(app, bdom, helpers
 ) {
   let { text, createBlock, list, multi, html, toggler, comment } = bdom;
@@ -723,7 +723,7 @@ exports[`lifecycle hooks timeout in onWillUpdateProps emits a warning 1`] = `
 }"
 `;
 
-exports[`lifecycle hooks timeout in onWillUpdateProps emits a warning 2`] = `
+exports[`lifecycle hooks timeout in onWillUpdateProps emits a console log 2`] = `
 "function anonymous(app, bdom, helpers
 ) {
   let { text, createBlock, list, multi, html, toggler, comment } = bdom;

tests/components/__snapshots__/props.test.ts.snap

@@ -66,6 +66,29 @@ exports[`.alike suffix in a simple case 2`] = `
 }"
 `;
 
+exports[`.translate props are translated 1`] = `
+"function anonymous(app, bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, comment } = bdom;
+  const comp1 = app.createComponent(\`Child\`, true, false, false, []);
+  
+  return function template(ctx, node, key = \\"\\") {
+    return comp1({message: \`translated message\`}, key + \`__1\`, node, this, null);
+  }
+}"
+`;
+
+exports[`.translate props are translated 2`] = `
+"function anonymous(app, bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, comment } = bdom;
+  
+  return function template(ctx, node, key = \\"\\") {
+    return text(ctx['props'].message);
+  }
+}"
+`;
+
 exports[`basics accept ES6-like syntax for props (with getters) 1`] = `
 "function anonymous(app, bdom, helpers
 ) {
@@ -412,6 +435,29 @@ exports[`can bind function prop with bind suffix 2`] = `
 }"
 `;
 
+exports[`can use .translate suffix 1`] = `
+"function anonymous(app, bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, comment } = bdom;
+  const comp1 = app.createComponent(\`Child\`, true, false, false, []);
+  
+  return function template(ctx, node, key = \\"\\") {
+    return comp1({message: \`some message\`}, key + \`__1\`, node, this, null);
+  }
+}"
+`;
+
+exports[`can use .translate suffix 2`] = `
+"function anonymous(app, bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, comment } = bdom;
+  
+  return function template(ctx, node, key = \\"\\") {
+    return text(ctx['props'].message);
+  }
+}"
+`;
+
 exports[`do not crash when binding anonymous function prop with bind suffix 1`] = `
 "function anonymous(app, bdom, helpers
 ) {

tests/components/__snapshots__/props_validation.test.ts.snap

@@ -924,6 +924,20 @@ exports[`props validation props: list of strings 1`] = `
 }"
 `;
 
+exports[`props validation validate props for root component 1`] = `
+"function anonymous(app, bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, comment } = bdom;
+  
+  let block1 = createBlock(\`<div><block-text-0/></div>\`);
+  
+  return function template(ctx, node, key = \\"\\") {
+    let txt1 = ctx['message'];
+    return block1([txt1]);
+  }
+}"
+`;
+
 exports[`props validation validate simple types 1`] = `
 "function anonymous(app, bdom, helpers
 ) {

tests/components/__snapshots__/slots.test.ts.snap

@@ -1,5 +1,30 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
+exports[`slots .translate slot props are translated 1`] = `
+"function anonymous(app, bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, comment } = bdom;
+  let { capture, markRaw } = helpers;
+  const comp1 = app.createComponent(\`Child\`, true, true, false, []);
+  
+  return function template(ctx, node, key = \\"\\") {
+    const ctx1 = capture(ctx);
+    return comp1({slots: markRaw({'default': {message: \`translated message\`}})}, key + \`__1\`, node, this, null);
+  }
+}"
+`;
+
+exports[`slots .translate slot props are translated 2`] = `
+"function anonymous(app, bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, comment } = bdom;
+  
+  return function template(ctx, node, key = \\"\\") {
+    return text(ctx['props'].slots.default.message);
+  }
+}"
+`;
+
 exports[`slots can define a default content 1`] = `
 "function anonymous(app, bdom, helpers
 ) {
@@ -201,6 +226,31 @@ exports[`slots can render only empty slot 1`] = `
 }"
 `;
 
+exports[`slots can use .translate suffix on slot props 1`] = `
+"function anonymous(app, bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, comment } = bdom;
+  let { capture, markRaw } = helpers;
+  const comp1 = app.createComponent(\`Child\`, true, true, false, []);
+  
+  return function template(ctx, node, key = \\"\\") {
+    const ctx1 = capture(ctx);
+    return comp1({slots: markRaw({'default': {message: \`some message\`}})}, key + \`__1\`, node, this, null);
+  }
+}"
+`;
+
+exports[`slots can use .translate suffix on slot props 2`] = `
+"function anonymous(app, bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, comment } = bdom;
+  
+  return function template(ctx, node, key = \\"\\") {
+    return text(ctx['props'].slots.default.message);
+  }
+}"
+`;
+
 exports[`slots can use component in default-content of t-slot 1`] = `
 "function anonymous(app, bdom, helpers
 ) {

tests/components/error_handling.test.ts

@@ -157,7 +157,7 @@ describe("basics", () => {
     } catch (e) {
       error = e as Error;
     }
-    const expectedErrorMessage = `Failed to compile anonymous template: Unexpected identifier
+    const expectedErrorMessage = `Failed to compile anonymous template: Unexpected identifier 'ctx'
 
 generated code:
 function(app, bdom, helpers) {
@@ -182,7 +182,7 @@ function(app, bdom, helpers) {
       static components = { Child };
       static template = xml`<Child/>`;
     }
-    const expectedErrorMessage = `Failed to compile anonymous template: Unexpected identifier
+    const expectedErrorMessage = `Failed to compile anonymous template: Unexpected identifier 'ctx'
 
 generated code:
 function(app, bdom, helpers) {
@@ -564,6 +564,82 @@ describe("can catch errors", () => {
     expect(mockConsoleWarn).toBeCalledTimes(0);
   });
 
+  test("can catch an error in onmounted", async () => {
+    class ErrorComponent extends Component {
+      static template = xml`<div>Error!!!</div>`;
+      setup() {
+        useLogLifecycle();
+        onMounted(() => {
+          throw new Error("error");
+        });
+      }
+    }
+    class PerfectComponent extends Component {
+      static template = xml`<div>perfect</div>`;
+      setup() {
+        useLogLifecycle();
+      }
+    }
+    class Main extends Component {
+      static template = xml`Main<t t-if="state.ok" t-component="component"/>`;
+      component: any;
+      state: any;
+      setup() {
+        this.state = useState({ ok: false });
+        useLogLifecycle();
+        this.component = ErrorComponent;
+        onError(() => {
+          this.component = PerfectComponent;
+          this.render();
+        });
+      }
+    }
+
+    const app = await mount(Main, fixture);
+    expect(steps.splice(0)).toMatchInlineSnapshot(`
+      Array [
+        "Main:setup",
+        "Main:willStart",
+        "Main:willRender",
+        "Main:rendered",
+        "Main:mounted",
+      ]
+    `);
+    expect(fixture.innerHTML).toBe("Main");
+    (app as any).state.ok = true;
+    await nextTick();
+    expect(fixture.innerHTML).toBe("Main<div>Error!!!</div>");
+    expect(steps.splice(0)).toMatchInlineSnapshot(`
+      Array [
+        "Main:willRender",
+        "ErrorComponent:setup",
+        "ErrorComponent:willStart",
+        "Main:rendered",
+        "ErrorComponent:willRender",
+        "ErrorComponent:rendered",
+        "Main:willPatch",
+        "ErrorComponent:mounted",
+        "Main:willRender",
+        "PerfectComponent:setup",
+        "PerfectComponent:willStart",
+        "Main:rendered",
+      ]
+    `);
+    await nextTick();
+    expect(steps.splice(0)).toMatchInlineSnapshot(`
+      Array [
+        "PerfectComponent:willRender",
+        "PerfectComponent:rendered",
+        "Main:willPatch",
+        "ErrorComponent:willUnmount",
+        "ErrorComponent:willDestroy",
+        "PerfectComponent:mounted",
+        "Main:patched",
+      ]
+    `);
+    expect(fixture.innerHTML).toBe("Main<div>perfect</div>");
+  });
+
   test("calling a hook outside setup should crash", async () => {
     class Root extends Component {
       static template = xml`<t t-esc="state.value"/>`;
@@ -1602,4 +1678,198 @@ describe("can catch errors", () => {
     `);
     expect(fixture.innerHTML).toBe("2");
   });
+
+  test("error in onMounted, graceful recovery", async () => {
+    class Child extends Component {
+      static template = xml`abc`;
+      setup() {
+        useLogLifecycle();
+      }
+    }
+
+    class OtherChild extends Component {
+      static template = xml`def`;
+      setup() {
+        useLogLifecycle();
+      }
+    }
+
+    class Boom extends Component {
+      static template = xml`boom`;
+      setup() {
+        useLogLifecycle();
+        onMounted(() => {
+          throw new Error("boom");
+        });
+      }
+    }
+
+    class Parent extends Component {
+      static template = xml`parent<Child/><Boom/>`;
+      static components = { Child, Boom };
+      setup() {
+        useLogLifecycle();
+      }
+    }
+
+    class Root extends Component {
+      static template = xml`<t t-component="component"/>`;
+
+      component: any = Parent;
+      setup() {
+        useLogLifecycle();
+        onError(() => {
+          logStep("error");
+          this.component = OtherChild;
+          this.render();
+        });
+      }
+    }
+
+    await mount(Root, fixture);
+    expect(fixture.innerHTML).toBe("def");
+
+    expect(steps.splice(0)).toMatchInlineSnapshot(`
+      Array [
+        "Root:setup",
+        "Root:willStart",
+        "Root:willRender",
+        "Parent:setup",
+        "Parent:willStart",
+        "Root:rendered",
+        "Parent:willRender",
+        "Child:setup",
+        "Child:willStart",
+        "Boom:setup",
+        "Boom:willStart",
+        "Parent:rendered",
+        "Child:willRender",
+        "Child:rendered",
+        "Boom:willRender",
+        "Boom:rendered",
+        "Boom:mounted",
+        "error",
+        "Root:willRender",
+        "OtherChild:setup",
+        "OtherChild:willStart",
+        "Root:rendered",
+        "OtherChild:willRender",
+        "OtherChild:rendered",
+        "OtherChild:mounted",
+        "Root:mounted",
+      ]
+    `);
+  });
+
+  test("error in onMounted, graceful recovery, variation", async () => {
+    class Child extends Component {
+      static template = xml`abc`;
+      setup() {
+        useLogLifecycle();
+      }
+    }
+
+    class OtherChild extends Component {
+      static template = xml`def`;
+      setup() {
+        useLogLifecycle();
+      }
+    }
+
+    class Boom extends Component {
+      static template = xml`boom`;
+      setup() {
+        useLogLifecycle();
+        onMounted(() => {
+          throw new Error("boom");
+        });
+      }
+    }
+
+    class Parent extends Component {
+      static template = xml`parent<Child/><Boom/>`;
+      static components = { Child, Boom };
+      setup() {
+        useLogLifecycle();
+      }
+    }
+
+    class Root extends Component {
+      static template = xml`R<t t-if="state.gogogo" t-component="component"/>`;
+
+      component: any = Parent;
+      state = useState({ gogogo: false });
+
+      setup() {
+        useLogLifecycle();
+        onError(() => {
+          logStep("error");
+          this.component = OtherChild;
+          this.render();
+        });
+      }
+    }
+
+    const root = await mount(Root, fixture);
+    expect(fixture.innerHTML).toBe("R");
+
+    // standard mounting process
+    expect(steps.splice(0)).toMatchInlineSnapshot(`
+      Array [
+        "Root:setup",
+        "Root:willStart",
+        "Root:willRender",
+        "Root:rendered",
+        "Root:mounted",
+      ]
+    `);
+
+    root.state.gogogo = true;
+    await nextTick();
+
+    expect(fixture.innerHTML).toBe("Rparentabcboom");
+    // rerender, root creates sub components, it crashes, tries to recover
+    expect(steps.splice(0)).toMatchInlineSnapshot(`
+      Array [
+        "Root:willRender",
+        "Parent:setup",
+        "Parent:willStart",
+        "Root:rendered",
+        "Parent:willRender",
+        "Child:setup",
+        "Child:willStart",
+        "Boom:setup",
+        "Boom:willStart",
+        "Parent:rendered",
+        "Child:willRender",
+        "Child:rendered",
+        "Boom:willRender",
+        "Boom:rendered",
+        "Root:willPatch",
+        "Boom:mounted",
+        "error",
+        "Root:willRender",
+        "OtherChild:setup",
+        "OtherChild:willStart",
+        "Root:rendered",
+      ]
+    `);
+
+    await nextTick();
+    expect(fixture.innerHTML).toBe("Rdef");
+
+    expect(steps.splice(0)).toMatchInlineSnapshot(`
+      Array [
+        "OtherChild:willRender",
+        "OtherChild:rendered",
+        "Root:willPatch",
+        "Child:willDestroy",
+        "Boom:willUnmount",
+        "Boom:willDestroy",
+        "Parent:willDestroy",
+        "OtherChild:mounted",
+        "Root:patched",
+      ]
+    `);
+  });
 });

tests/components/lifecycle.test.ts

@@ -112,10 +112,10 @@ describe("lifecycle hooks", () => {
     await mount(Test, fixture);
   });
 
-  test("timeout in onWillStart emits a warning", async () => {
-    const { warn } = console;
-    let warnArgs: any[];
-    console.warn = jest.fn((...args) => (warnArgs = args));
+  test("timeout in onWillStart emits a console log", async () => {
+    const { log } = console;
+    let logArgs: any[];
+    console.log = jest.fn((...args) => (logArgs = args));
     const { setTimeout } = window;
     let timeoutCbs: any = {};
     let timeoutId = 0;
@@ -138,17 +138,17 @@ describe("lifecycle hooks", () => {
       }
       await nextMicroTick();
       await nextMicroTick();
-      expect(console.warn).toHaveBeenCalledTimes(1);
-      expect(warnArgs![0]!.message).toBe("onWillStart's promise hasn't resolved after 3 seconds");
+      expect(console.log).toHaveBeenCalledTimes(1);
+      expect(logArgs![0]!.message).toBe("onWillStart's promise hasn't resolved after 3 seconds");
     } finally {
-      console.warn = warn;
+      console.log = log;
       window.setTimeout = setTimeout;
     }
   });
 
-  test("timeout in onWillStart doesn't emit a warning if app is destroyed", async () => {
-    const { warn } = console;
-    console.warn = jest.fn();
+  test("timeout in onWillStart doesn't emit a console log if app is destroyed", async () => {
+    const { log } = console;
+    console.log = jest.fn();
     const { setTimeout } = window;
     let timeoutCbs: any = {};
     let timeoutId = 0;
@@ -172,14 +172,14 @@ describe("lifecycle hooks", () => {
       }
       await nextMicroTick();
       await nextMicroTick();
-      expect(console.warn).toHaveBeenCalledTimes(0);
+      expect(console.log).toHaveBeenCalledTimes(0);
     } finally {
-      console.warn = warn;
+      console.log = log;
       window.setTimeout = setTimeout;
     }
   });
 
-  test("timeout in onWillUpdateProps emits a warning", async () => {
+  test("timeout in onWillUpdateProps emits a console log", async () => {
     class Child extends Component {
       static template = xml``;
       setup() {
@@ -193,9 +193,9 @@ describe("lifecycle hooks", () => {
     }
     const parent = await mount(Parent, fixture, { test: true });
 
-    const { warn } = console;
-    let warnArgs: any[];
-    console.warn = jest.fn((...args) => (warnArgs = args));
+    const { log } = console;
+    let logArgs: any[];
+    console.log = jest.fn((...args) => (logArgs = args));
     const { setTimeout } = window;
     let timeoutCbs: any = {};
     let timeoutId = 0;
@@ -218,12 +218,12 @@ describe("lifecycle hooks", () => {
         delete timeoutCbs[id];
       }
       await tick;
-      expect(console.warn).toHaveBeenCalledTimes(1);
-      expect(warnArgs![0]!.message).toBe(
+      expect(console.log).toHaveBeenCalledTimes(1);
+      expect(logArgs![0]!.message).toBe(
         "onWillUpdateProps's promise hasn't resolved after 3 seconds"
       );
     } finally {
-      console.warn = warn;
+      console.log = log;
       window.setTimeout = setTimeout;
     }
   });

tests/components/props.test.ts

@@ -299,6 +299,34 @@ test("bound functions are considered 'alike'", async () => {
   expect(fixture.innerHTML).toBe("3child");
 });
 
+test("can use .translate suffix", async () => {
+  class Child extends Component {
+    static template = xml`<t t-esc="props.message"/>`;
+  }
+
+  class Parent extends Component {
+    static template = xml`<Child message.translate="some message"/>`;
+    static components = { Child };
+  }
+
+  await mount(Parent, fixture);
+  expect(fixture.innerHTML).toBe("some message");
+});
+
+test(".translate props are translated", async () => {
+  class Child extends Component {
+    static template = xml`<t t-esc="props.message"/>`;
+  }
+
+  class Parent extends Component {
+    static template = xml`<Child message.translate="some message"/>`;
+    static components = { Child };
+  }
+
+  await mount(Parent, fixture, { translateFn: () => "translated message" });
+  expect(fixture.innerHTML).toBe("translated message");
+});
+
 test("throw if prop uses an unknown suffix", async () => {
   class Child extends Component {
     static template = xml`<t t-esc="props.val"/>`;

tests/components/slots.test.ts

@@ -179,6 +179,34 @@ describe("slots", () => {
     expect(fixture.innerHTML).toBe("<span>default empty</span>");
   });
 
+  test("can use .translate suffix on slot props", async () => {
+    class Child extends Component {
+      static template = xml`<t t-esc="props.slots.default.message"/>`;
+    }
+
+    class Parent extends Component {
+      static template = xml`<Child><t t-set-slot="default" message.translate="some message"/></Child>`;
+      static components = { Child };
+    }
+
+    await mount(Parent, fixture);
+    expect(fixture.innerHTML).toBe("some message");
+  });
+
+  test(".translate slot props are translated", async () => {
+    class Child extends Component {
+      static template = xml`<t t-esc="props.slots.default.message"/>`;
+    }
+
+    class Parent extends Component {
+      static template = xml`<Child><t t-set-slot="default" message.translate="some message"/></Child>`;
+      static components = { Child };
+    }
+
+    await mount(Parent, fixture, { translateFn: () => "translated message" });
+    expect(fixture.innerHTML).toBe("translated message");
+  });
+
   test("default slot with slot scope: shorthand syntax", async () => {
     let child: any;
     class Child extends Component {

tools/devtools/manifest-chrome.json

@@ -14,7 +14,7 @@
     "default_popup": "popup_app/popup.html"
   },
   "permissions": ["scripting", "storage"],
-  "host_permissions": ["http://*/*", "https://*/*"],
+  "host_permissions": ["http://*/*", "https://*/*", "file://*"],
   "content_security_policy": {
     "script-src": "self",
     "object-src": "self"

tools/devtools/src/page_scripts/owl_devtools_global_hook.js

@@ -109,23 +109,34 @@
         object(obj) {
           const result = [];
           let length = 0;
-          for (const [key, value] of Object.entries(obj)) {
-            if (length > 25) {
-              result.push("...");
-              break;
+          if (obj instanceof String) {
+            result[0] = `'${obj.toString()}'`;
+          } else if (obj instanceof Array) {
+            return `${obj.constructor.name} ${this.array([...obj])}`;
+          } else if (obj instanceof Number) {
+            result[0] = obj.toString();
+          } else {
+            for (const [key, value] of Object.entries(obj)) {
+              if (length > 25) {
+                result.push("...");
+                break;
+              }
+              const element = key + ": " + this.serializeItem(value);
+              length += element.length;
+              result.push(element);
+            }
+            for (const key of Object.getOwnPropertySymbols(obj)) {
+              if (length > 25) {
+                result.push("...");
+                break;
+              }
+              const element = key.toString() + ": " + this.serializeItem(obj[key]);
+              length += element.length;
+              result.push(element);
             }
-            const element = key + ": " + this.serializeItem(value);
-            length += element.length;
-            result.push(element);
           }
-          for (const key of Object.getOwnPropertySymbols(obj)) {
-            if (length > 25) {
-              result.push("...");
-              break;
-            }
-            const element = key.toString() + ": " + this.serializeItem(obj[key]);
-            length += element.length;
-            result.push(element);
+          if (obj.constructor.name !== "Object") {
+            return obj.constructor.name + " {" + result.join(", ") + "}";
           }
           return "{" + result.join(", ") + "}";
         },
@@ -823,7 +834,7 @@
               child.contentType = "set";
               child.hasChildren = true;
               break;
-            case obj instanceof Array:
+            case obj.constructor.name === "Array":
               child.contentType = "array";
               child.hasChildren = obj.length > 0;
               break;
@@ -834,7 +845,9 @@
             case obj instanceof Object:
               child.contentType = "object";
               child.hasChildren =
-                Object.keys(obj).length || Object.getOwnPropertySymbols(obj).length;
+                Object.keys(obj).length ||
+                Object.getOwnPropertySymbols(obj).length ||
+                obj.constructor.name !== "Object";
               break;
             default:
               child.contentType = typeof obj;

tools/release.js

@@ -140,7 +140,6 @@ async function startRelease() {
   }
 
   // ---------------------------------------------------------------------------
-
   log(`Step ${step++}/${STEPS}: Creating the release...`);
   const relaseResult = await execCommand(`gh release create v${next} dist/*.js dist/*.zip ${draft} -F ${file}`);
   if (relaseResult !== 0) {