[FIX] fix some issues with t-out with falsy values, and with default value

src/compiler/code_generator.ts

@@ -754,16 +754,22 @@ export class CodeGenerator {
       this.insertAnchor(block);
     }
     block = this.createBlock(block, "html", ctx);
-    this.helpers.add(ast.expr === "0" ? "zero" : "safeOutput");
+    let blockStr;
-    let expr = ast.expr === "0" ? "ctx[zero]" : `safeOutput(${compileExpr(ast.expr)})`;
+    if (ast.expr === "0") {
-    if (ast.body) {
+      this.helpers.add("zero");
-      const nextId = BlockDescription.nextBlockId;
+      blockStr = `ctx[zero]`;
+    } else if (ast.body) {
+      let bodyValue = null;
+      bodyValue = BlockDescription.nextBlockId;
       const subCtx: Context = createContext(ctx);
       this.compileAST({ type: ASTType.Multi, content: ast.body }, subCtx);
-      this.helpers.add("withDefault");
+      this.helpers.add("safeOutput");
-      expr = `withDefault(${expr}, b${nextId})`;
+      blockStr = `safeOutput(${compileExpr(ast.expr)}, b${bodyValue})`;
+    } else {
+      this.helpers.add("safeOutput");
+      blockStr = `safeOutput(${compileExpr(ast.expr)})`;
     }
-    this.insertBlock(`${expr}`, block, ctx);
+    this.insertBlock(blockStr, block, ctx);
   }
 
   compileTIf(ast: ASTTif, ctx: Context, nextNode?: ASTDomNode) {

src/runtime/template_helpers.ts

@@ -129,9 +129,9 @@ class LazyValue {
 /*
  * Safely outputs `value` as a block depending on the nature of `value`
  */
-export function safeOutput(value: any): ReturnType<typeof toggler> {
+export function safeOutput(value: any, defaultValue?: any): ReturnType<typeof toggler> {
-  if (!value) {
+  if (value === undefined) {
-    return value;
+    return defaultValue ? toggler("default", defaultValue) : toggler("undefined", text(""));
   }
   let safeKey;
   let block;

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

@@ -133,6 +133,31 @@ exports[`t-esc t-esc is escaped 1`] = `
 }"
 `;
 
+exports[`t-esc t-esc with the 0 number 1`] = `
+"function anonymous(app, bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, comment } = bdom;
+  
+  return function template(ctx, node, key = \\"\\") {
+    return text(ctx['var']);
+  }
+}"
+`;
+
+exports[`t-esc t-esc with the 0 number, in a p 1`] = `
+"function anonymous(app, bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, comment } = bdom;
+  
+  let block1 = createBlock(\`<p><block-text-0/></p>\`);
+  
+  return function template(ctx, node, key = \\"\\") {
+    let txt1 = ctx['var'];
+    return block1([txt1]);
+  }
+}"
+`;
+
 exports[`t-esc t-esc work with spread operator 1`] = `
 "function anonymous(app, bdom, helpers
 ) {
@@ -183,6 +208,17 @@ exports[`t-esc t-esc=0 is escaped 2`] = `
 }"
 `;
 
+exports[`t-esc top level t-esc with undefined 1`] = `
+"function anonymous(app, bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, comment } = bdom;
+  
+  return function template(ctx, node, key = \\"\\") {
+    return text(ctx['var']);
+  }
+}"
+`;
+
 exports[`t-esc variable 1`] = `
 "function anonymous(app, bdom, helpers
 ) {

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

@@ -217,13 +217,13 @@ exports[`t-out t-out on a node with a body, as a default 1`] = `
 "function anonymous(app, bdom, helpers
 ) {
   let { text, createBlock, list, multi, html, toggler, comment } = bdom;
-  let { safeOutput, withDefault } = helpers;
+  let { safeOutput } = helpers;
   
   let block1 = createBlock(\`<span><block-child-0/></span>\`);
   
   return function template(ctx, node, key = \\"\\") {
     const b3 = text(\`nope\`);
-    const b2 = withDefault(safeOutput(ctx['var']), b3);
+    const b2 = safeOutput(ctx['var'], b3);
     return block1([], [b2]);
   }
 }"
@@ -233,14 +233,14 @@ exports[`t-out t-out on a node with a dom node in body, as a default 1`] = `
 "function anonymous(app, bdom, helpers
 ) {
   let { text, createBlock, list, multi, html, toggler, comment } = bdom;
-  let { safeOutput, withDefault } = helpers;
+  let { safeOutput } = helpers;
   
   let block1 = createBlock(\`<span><block-child-0/></span>\`);
   let block3 = createBlock(\`<div>nope</div>\`);
   
   return function template(ctx, node, key = \\"\\") {
     const b3 = block3();
-    const b2 = withDefault(safeOutput(ctx['var']), b3);
+    const b2 = safeOutput(ctx['var'], b3);
     return block1([], [b2]);
   }
 }"
@@ -407,6 +407,45 @@ exports[`t-out t-out with just a t-set t-value in body 1`] = `
 }"
 `;
 
+exports[`t-out t-out with the 0 number 1`] = `
+"function anonymous(app, bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, comment } = bdom;
+  let { safeOutput } = helpers;
+  
+  return function template(ctx, node, key = \\"\\") {
+    return safeOutput(ctx['var']);
+  }
+}"
+`;
+
+exports[`t-out t-out with the 0 number, in a p 1`] = `
+"function anonymous(app, bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, comment } = bdom;
+  let { safeOutput } = helpers;
+  
+  let block1 = createBlock(\`<p><block-child-0/></p>\`);
+  
+  return function template(ctx, node, key = \\"\\") {
+    const b2 = safeOutput(ctx['var']);
+    return block1([], [b2]);
+  }
+}"
+`;
+
+exports[`t-out top level t-out with undefined 1`] = `
+"function anonymous(app, bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, comment } = bdom;
+  let { safeOutput } = helpers;
+  
+  return function template(ctx, node, key = \\"\\") {
+    return safeOutput(ctx['var']);
+  }
+}"
+`;
+
 exports[`t-out variable 1`] = `
 "function anonymous(app, bdom, helpers
 ) {

tests/compiler/t_esc.test.ts

@@ -67,6 +67,21 @@ describe("t-esc", () => {
     );
   });
 
+  test("t-esc with the 0 number", () => {
+    const template = `<t t-esc="var"/>`;
+    expect(renderToString(template, { var: 0 })).toBe("0");
+  });
+
+  test("t-esc with the 0 number, in a p", () => {
+    const template = `<p><t t-esc="var"/></p>`;
+    expect(renderToString(template, { var: 0 })).toBe("<p>0</p>");
+  });
+
+  test("top level t-esc with undefined", () => {
+    const template = `<t t-esc="var"/>`;
+    expect(renderToString(template, { var: undefined })).toBe("");
+  });
+
   test("falsy values in text nodes", () => {
     const template = `
         <t t-esc="v1"/>:<t t-esc="v2"/>:<t t-esc="v3"/>:<t t-esc="v4"/>:<t t-esc="v5"/>`;

tests/compiler/t_out.test.ts

@@ -47,6 +47,21 @@ describe("t-out", () => {
     expect(renderToString(template, { var: new String("ok") })).toBe("<span>ok</span>");
   });
 
+  test("t-out with the 0 number", () => {
+    const template = `<t t-out="var"/>`;
+    expect(renderToString(template, { var: 0 })).toBe("0");
+  });
+
+  test("t-out with the 0 number, in a p", () => {
+    const template = `<p><t t-out="var"/></p>`;
+    expect(renderToString(template, { var: 0 })).toBe("<p>0</p>");
+  });
+
+  test("top level t-out with undefined", () => {
+    const template = `<t t-out="var"/>`;
+    expect(renderToString(template, { var: undefined })).toBe("");
+  });
+
   test("with an extended String class", () => {
     class LoveString extends String {
       valueOf(): string {

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

@@ -1308,6 +1308,18 @@ exports[`t-out in components can switch the contents of two t-out repeatedly 1`]
 }"
 `;
 
+exports[`t-out in components t-out and updating falsy values,  1`] = `
+"function anonymous(app, bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, comment } = bdom;
+  let { safeOutput } = helpers;
+  
+  return function template(ctx, node, key = \\"\\") {
+    return safeOutput(ctx['state'].a);
+  }
+}"
+`;
+
 exports[`t-out in components update properly on state changes 1`] = `
 "function anonymous(app, bdom, helpers
 ) {

tests/components/basics.test.ts

@@ -1084,4 +1084,25 @@ describe("t-out in components", () => {
     await nextTick();
     expect(fixture.innerHTML).toBe("<div>1</div><div>2</div>");
   });
+
+  test("t-out and updating falsy values, ", async () => {
+    class Test extends Component {
+      static template = xml`<t t-out="state.a"/>`;
+      state: any = useState({ a: 0 });
+    }
+
+    const comp = await mount(Test, fixture);
+    expect(fixture.innerHTML).toBe("0");
+    comp.state.a = undefined;
+    await nextTick();
+    expect(fixture.innerHTML).toBe("");
+
+    comp.state.a = "hello"
+    await nextTick();
+    expect(fixture.innerHTML).toBe("hello");
+
+    comp.state.a = false;
+    await nextTick();
+    expect(fixture.innerHTML).toBe("false");
+  });
 });