[FIX] component: propagate errors to caller

Errors from mounted/willPatch/patched should be returned to caller
(either mount or render functions)

part of #410

src/component/component.ts

@@ -444,13 +444,9 @@ export class Component<T extends Env, Props extends {}> {
     }
     __owl__.isMounted = true;
     __owl__.currentFiber = null;
-    try {
-      this.mounted();
-      if (__owl__.mountedCB) {
-        __owl__.mountedCB();
-      }
-    } catch (e) {
-      console.error(e); // TODO : add a test
+    this.mounted();
+    if (__owl__.mountedCB) {
+      __owl__.mountedCB();
     }
   }
 

src/component/fiber.ts

@@ -196,16 +196,12 @@ export class Fiber {
     this._walk(doWork);
     let component: Component<any, any> = this.component;
     const patchLen = patchQueue.length;
-    try {
-      for (let i = 0; i < patchLen; i++) {
-        component = patchQueue[i].component;
-        if (component.__owl__.willPatchCB) {
-          component.__owl__.willPatchCB();
-        }
-        component.willPatch();
+    for (let i = 0; i < patchLen; i++) {
+      component = patchQueue[i].component;
+      if (component.__owl__.willPatchCB) {
+        component.__owl__.willPatchCB();
       }
-    } catch (e) {
-      console.error(e);
+      component.willPatch();
     }
     for (let i = 0; i < patchLen; i++) {
       const fiber = patchQueue[i];
@@ -213,16 +209,12 @@ export class Fiber {
       component.__patch(fiber.vnode);
       component.__owl__.currentFiber = null;
     }
-    try {
-      for (let i = patchLen - 1; i >= 0; i--) {
-        component = patchQueue[i].component;
-        component.patched();
-        if (component.__owl__.patchedCB) {
-          component.__owl__.patchedCB();
-        }
+    for (let i = patchLen - 1; i >= 0; i--) {
+      component = patchQueue[i].component;
+      component.patched();
+      if (component.__owl__.patchedCB) {
+        component.__owl__.patchedCB();
       }
-    } catch (e) {
-      console.error(e);
     }
   }
 

src/component/scheduler.ts

@@ -59,7 +59,11 @@ export class Scheduler {
       }
       if (task.fiber.counter === 0) {
         if (!task.fiber.error) {
-          task.fiber.complete();
+          try {
+            task.fiber.complete();
+          } catch (e) {
+            task.fiber.handleError(e);
+          }
         }
         task.callback();
         return false;

src/qweb/expression_parser.ts

@@ -164,7 +164,7 @@ const TOKENIZERS = [
   tokenizeNumber,
   tokenizeOperator,
   tokenizeSymbol,
-  tokenizeStatic,
+  tokenizeStatic
 ];
 
 /**

tests/component/component.test.ts

@@ -4646,6 +4646,90 @@ describe("component error handling (catchError)", () => {
     console.error = consoleError;
   });
 
+  test("an error in mounted call will reject the mount promise", async () => {
+    const consoleError = console.error;
+    console.error = jest.fn(() => {});
+
+    class App extends Component<any, any> {
+      static template = xml`<div>abc</div>`;
+      mounted() {
+        throw new Error("boom");
+      }
+    }
+
+    const app = new App();
+    let error;
+    try {
+      await app.mount(fixture);
+    } catch (e) {
+      error = e;
+    }
+    expect(error).toBeDefined();
+    expect(error.message).toBe("boom");
+    expect(fixture.innerHTML).toBe("");
+
+    expect(console.error).toBeCalledTimes(0);
+    console.error = consoleError;
+  });
+
+  test("an error in willPatch call will reject the render promise", async () => {
+    const consoleError = console.error;
+    console.error = jest.fn(() => {});
+
+    class App extends Component<any, any> {
+      static template = xml`<div><t t-esc="val"/></div>`;
+      val = 3;
+      willPatch() {
+        throw new Error("boom");
+      }
+    }
+
+    const app = new App();
+    await app.mount(fixture);
+    app.val = 4;
+    let error;
+    try {
+      await app.render();
+    } catch (e) {
+      error = e;
+    }
+    expect(error).toBeDefined();
+    expect(error.message).toBe("boom");
+    expect(fixture.innerHTML).toBe("");
+
+    expect(console.error).toBeCalledTimes(0);
+    console.error = consoleError;
+  });
+
+  test("an error in patched call will reject the render promise", async () => {
+    const consoleError = console.error;
+    console.error = jest.fn(() => {});
+
+    class App extends Component<any, any> {
+      static template = xml`<div><t t-esc="val"/></div>`;
+      val = 3;
+      patched() {
+        throw new Error("boom");
+      }
+    }
+
+    const app = new App();
+    await app.mount(fixture);
+    app.val = 4;
+    let error;
+    try {
+      await app.render();
+    } catch (e) {
+      error = e;
+    }
+    expect(error).toBeDefined();
+    expect(error.message).toBe("boom");
+    expect(fixture.innerHTML).toBe("");
+
+    expect(console.error).toBeCalledTimes(0);
+    console.error = consoleError;
+  });
+
   test("a rendering error in a sub component will reject the mount promise", async () => {
     const consoleError = console.error;
     console.error = jest.fn(() => {});

tests/qweb/qweb_expressions.test.ts

@@ -44,7 +44,8 @@ describe("tokenizer", () => {
       { type: "OPERATOR", value: "!=" }
     ]);
     expect(tokenize("typeof a")).toEqual([
-      {"type": "OPERATOR", "value": "typeof "}, {"type": "SYMBOL", "value": "a"}
+      { type: "OPERATOR", value: "typeof " },
+      { type: "SYMBOL", value: "a" }
     ]);
   });