Use undefinedWideningType

Andy Hanson · Andy Hanson · commit f910468ac1f9 · 2018-03-02T15:50:33.000-08:00
diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
@@ -18389,7 +18389,7 @@ namespace ts {
 
         function getYieldedTypeOfYieldExpression(node: YieldExpression, isAsync: boolean, checkMode?: CheckMode): Type {
             const errorNode = node.expression || node;
-            const expressionType = node.expression ? checkExpressionCached(node.expression, checkMode) : undefinedType;
+            const expressionType = node.expression ? checkExpressionCached(node.expression, checkMode) : undefinedWideningType;
             // A yield* expression effectively yields everything that its operand yields
             const yieldedType = node.asteriskToken ? checkIteratedTypeOrElementType(expressionType, errorNode, /*allowStringInput*/ false, isAsync) : expressionType;
             return !isAsync ? yieldedType : getAwaitedType(yieldedType, errorNode, node.asteriskToken
diff --git a/tests/baselines/reference/FunctionDeclaration9_es6.types b/tests/baselines/reference/FunctionDeclaration9_es6.types
@@ -1,11 +1,11 @@
 === tests/cases/conformance/es6/functionDeclarations/FunctionDeclaration9_es6.ts ===
 function * foo() {
->foo : () => IterableIterator<undefined>
+>foo : () => IterableIterator<any>
 
   var v = { [yield]: foo }
->v : { [x: number]: () => IterableIterator<undefined>; }
->{ [yield]: foo } : { [x: number]: () => IterableIterator<undefined>; }
->[yield] : () => IterableIterator<undefined>
+>v : { [x: number]: () => IterableIterator<any>; }
+>{ [yield]: foo } : { [x: number]: () => IterableIterator<any>; }
+>[yield] : () => IterableIterator<any>
 >yield : any
->foo : () => IterableIterator<undefined>
+>foo : () => IterableIterator<any>
 }
diff --git a/tests/baselines/reference/YieldExpression13_es6.types b/tests/baselines/reference/YieldExpression13_es6.types
@@ -1,5 +1,5 @@
 === tests/cases/conformance/es6/yieldExpressions/YieldExpression13_es6.ts ===
 function* foo() { yield }
->foo : () => IterableIterator<undefined>
+>foo : () => IterableIterator<any>
 >yield : any
 
diff --git a/tests/baselines/reference/YieldExpression3_es6.types b/tests/baselines/reference/YieldExpression3_es6.types
@@ -1,6 +1,6 @@
 === tests/cases/conformance/es6/yieldExpressions/YieldExpression3_es6.ts ===
 function* foo() {
->foo : () => IterableIterator<undefined>
+>foo : () => IterableIterator<any>
 
   yield
 >yield : any
diff --git a/tests/baselines/reference/YieldExpression4_es6.types b/tests/baselines/reference/YieldExpression4_es6.types
@@ -1,6 +1,6 @@
 === tests/cases/conformance/es6/yieldExpressions/YieldExpression4_es6.ts ===
 function* foo() {
->foo : () => IterableIterator<undefined>
+>foo : () => IterableIterator<any>
 
   yield;
 >yield : any
diff --git a/tests/baselines/reference/emitter.asyncGenerators.classMethods.es2015.types b/tests/baselines/reference/emitter.asyncGenerators.classMethods.es2015.types
@@ -11,7 +11,7 @@ class C2 {
 >C2 : C2
 
     async * f() {
->f : () => AsyncIterableIterator<undefined>
+>f : () => AsyncIterableIterator<any>
 
         const x = yield;
 >x : any
diff --git a/tests/baselines/reference/emitter.asyncGenerators.classMethods.es5.types b/tests/baselines/reference/emitter.asyncGenerators.classMethods.es5.types
@@ -11,7 +11,7 @@ class C2 {
 >C2 : C2
 
     async * f() {
->f : () => AsyncIterableIterator<undefined>
+>f : () => AsyncIterableIterator<any>
 
         const x = yield;
 >x : any
diff --git a/tests/baselines/reference/emitter.asyncGenerators.classMethods.esnext.types b/tests/baselines/reference/emitter.asyncGenerators.classMethods.esnext.types
@@ -11,7 +11,7 @@ class C2 {
 >C2 : C2
 
     async * f() {
->f : () => AsyncIterableIterator<undefined>
+>f : () => AsyncIterableIterator<any>
 
         const x = yield;
 >x : any
diff --git a/tests/baselines/reference/emitter.asyncGenerators.functionDeclarations.es2015.types b/tests/baselines/reference/emitter.asyncGenerators.functionDeclarations.es2015.types
@@ -4,7 +4,7 @@ async function * f1() {
 }
 === tests/cases/conformance/emitter/es2015/asyncGenerators/F2.ts ===
 async function * f2() {
->f2 : () => AsyncIterableIterator<undefined>
+>f2 : () => AsyncIterableIterator<any>
 
     const x = yield;
 >x : any
diff --git a/tests/baselines/reference/emitter.asyncGenerators.functionDeclarations.es5.types b/tests/baselines/reference/emitter.asyncGenerators.functionDeclarations.es5.types
@@ -4,7 +4,7 @@ async function * f1() {
 }
 === tests/cases/conformance/emitter/es5/asyncGenerators/F2.ts ===
 async function * f2() {
->f2 : () => AsyncIterableIterator<undefined>
+>f2 : () => AsyncIterableIterator<any>
 
     const x = yield;
 >x : any
diff --git a/tests/baselines/reference/emitter.asyncGenerators.functionDeclarations.esnext.types b/tests/baselines/reference/emitter.asyncGenerators.functionDeclarations.esnext.types
@@ -4,7 +4,7 @@ async function * f1() {
 }
 === tests/cases/conformance/emitter/esnext/asyncGenerators/F2.ts ===
 async function * f2() {
->f2 : () => AsyncIterableIterator<undefined>
+>f2 : () => AsyncIterableIterator<any>
 
     const x = yield;
 >x : any
diff --git a/tests/baselines/reference/emitter.asyncGenerators.functionExpressions.es2015.types b/tests/baselines/reference/emitter.asyncGenerators.functionExpressions.es2015.types
@@ -5,8 +5,8 @@ const f1 = async function * () {
 }
 === tests/cases/conformance/emitter/es2015/asyncGenerators/F2.ts ===
 const f2 = async function * () {
->f2 : () => AsyncIterableIterator<undefined>
->async function * () {    const x = yield;} : () => AsyncIterableIterator<undefined>
+>f2 : () => AsyncIterableIterator<any>
+>async function * () {    const x = yield;} : () => AsyncIterableIterator<any>
 
     const x = yield;
 >x : any
diff --git a/tests/baselines/reference/emitter.asyncGenerators.functionExpressions.es5.types b/tests/baselines/reference/emitter.asyncGenerators.functionExpressions.es5.types
@@ -5,8 +5,8 @@ const f1 = async function * () {
 }
 === tests/cases/conformance/emitter/es5/asyncGenerators/F2.ts ===
 const f2 = async function * () {
->f2 : () => AsyncIterableIterator<undefined>
->async function * () {    const x = yield;} : () => AsyncIterableIterator<undefined>
+>f2 : () => AsyncIterableIterator<any>
+>async function * () {    const x = yield;} : () => AsyncIterableIterator<any>
 
     const x = yield;
 >x : any
diff --git a/tests/baselines/reference/emitter.asyncGenerators.functionExpressions.esnext.types b/tests/baselines/reference/emitter.asyncGenerators.functionExpressions.esnext.types
@@ -5,8 +5,8 @@ const f1 = async function * () {
 }
 === tests/cases/conformance/emitter/esnext/asyncGenerators/F2.ts ===
 const f2 = async function * () {
->f2 : () => AsyncIterableIterator<undefined>
->async function * () {    const x = yield;} : () => AsyncIterableIterator<undefined>
+>f2 : () => AsyncIterableIterator<any>
+>async function * () {    const x = yield;} : () => AsyncIterableIterator<any>
 
     const x = yield;
 >x : any
diff --git a/tests/baselines/reference/emitter.asyncGenerators.objectLiteralMethods.es2015.types b/tests/baselines/reference/emitter.asyncGenerators.objectLiteralMethods.es2015.types
@@ -9,11 +9,11 @@ const o1 = {
 }
 === tests/cases/conformance/emitter/es2015/asyncGenerators/O2.ts ===
 const o2 = {
->o2 : { f(): AsyncIterableIterator<undefined>; }
->{    async * f() {        const x = yield;    }} : { f(): AsyncIterableIterator<undefined>; }
+>o2 : { f(): AsyncIterableIterator<any>; }
+>{    async * f() {        const x = yield;    }} : { f(): AsyncIterableIterator<any>; }
 
     async * f() {
->f : () => AsyncIterableIterator<undefined>
+>f : () => AsyncIterableIterator<any>
 
         const x = yield;
 >x : any
diff --git a/tests/baselines/reference/emitter.asyncGenerators.objectLiteralMethods.es5.types b/tests/baselines/reference/emitter.asyncGenerators.objectLiteralMethods.es5.types
@@ -9,11 +9,11 @@ const o1 = {
 }
 === tests/cases/conformance/emitter/es5/asyncGenerators/O2.ts ===
 const o2 = {
->o2 : { f(): AsyncIterableIterator<undefined>; }
->{    async * f() {        const x = yield;    }} : { f(): AsyncIterableIterator<undefined>; }
+>o2 : { f(): AsyncIterableIterator<any>; }
+>{    async * f() {        const x = yield;    }} : { f(): AsyncIterableIterator<any>; }
 
     async * f() {
->f : () => AsyncIterableIterator<undefined>
+>f : () => AsyncIterableIterator<any>
 
         const x = yield;
 >x : any
diff --git a/tests/baselines/reference/emitter.asyncGenerators.objectLiteralMethods.esnext.types b/tests/baselines/reference/emitter.asyncGenerators.objectLiteralMethods.esnext.types
@@ -9,11 +9,11 @@ const o1 = {
 }
 === tests/cases/conformance/emitter/esnext/asyncGenerators/O2.ts ===
 const o2 = {
->o2 : { f(): AsyncIterableIterator<undefined>; }
->{    async * f() {        const x = yield;    }} : { f(): AsyncIterableIterator<undefined>; }
+>o2 : { f(): AsyncIterableIterator<any>; }
+>{    async * f() {        const x = yield;    }} : { f(): AsyncIterableIterator<any>; }
 
     async * f() {
->f : () => AsyncIterableIterator<undefined>
+>f : () => AsyncIterableIterator<any>
 
         const x = yield;
 >x : any
diff --git a/tests/baselines/reference/generatorES6InAMDModule.types b/tests/baselines/reference/generatorES6InAMDModule.types
@@ -1,6 +1,6 @@
 === tests/cases/compiler/generatorES6InAMDModule.ts ===
 export function* foo() {
->foo : () => IterableIterator<undefined>
+>foo : () => IterableIterator<any>
 
     yield
 >yield : any
diff --git a/tests/baselines/reference/generatorES6_1.types b/tests/baselines/reference/generatorES6_1.types
@@ -1,6 +1,6 @@
 === tests/cases/compiler/generatorES6_1.ts ===
 function* foo() {
->foo : () => IterableIterator<undefined>
+>foo : () => IterableIterator<any>
 
     yield
 >yield : any
diff --git a/tests/baselines/reference/generatorTypeCheck48.errors.txt b/tests/baselines/reference/generatorTypeCheck48.errors.txt
@@ -0,0 +1,17 @@
+tests/cases/conformance/es6/yieldExpressions/generatorTypeCheck48.ts(1,11): error TS7010: 'g', which lacks return-type annotation, implicitly has an 'any' return type.
+tests/cases/conformance/es6/yieldExpressions/generatorTypeCheck48.ts(5,11): error TS7010: 'h', which lacks return-type annotation, implicitly has an 'any' return type.
+
+
+==== tests/cases/conformance/es6/yieldExpressions/generatorTypeCheck48.ts (2 errors) ====
+    function* g() {
+              ~
+!!! error TS7010: 'g', which lacks return-type annotation, implicitly has an 'any' return type.
+        yield;
+    }
+    
+    function* h() {
+              ~
+!!! error TS7010: 'h', which lacks return-type annotation, implicitly has an 'any' return type.
+        yield undefined;
+    }
+    
diff --git a/tests/baselines/reference/generatorTypeCheck48.js b/tests/baselines/reference/generatorTypeCheck48.js
@@ -1,9 +1,17 @@
 //// [generatorTypeCheck48.ts]
 function* g() {
     yield;
-}
+}
+
+function* h() {
+    yield undefined;
+}
+
 
 //// [generatorTypeCheck48.js]
 function* g() {
     yield;
 }
+function* h() {
+    yield undefined;
+}
diff --git a/tests/baselines/reference/generatorTypeCheck48.symbols b/tests/baselines/reference/generatorTypeCheck48.symbols
@@ -4,3 +4,11 @@ function* g() {
 
     yield;
 }
+
+function* h() {
+>h : Symbol(h, Decl(generatorTypeCheck48.ts, 2, 1))
+
+    yield undefined;
+>undefined : Symbol(undefined)
+}
+
diff --git a/tests/baselines/reference/generatorTypeCheck48.types b/tests/baselines/reference/generatorTypeCheck48.types
@@ -1,7 +1,16 @@
 === tests/cases/conformance/es6/yieldExpressions/generatorTypeCheck48.ts ===
 function* g() {
->g : () => IterableIterator<undefined>
+>g : () => IterableIterator<any>
 
     yield;
 >yield : any
 }
+
+function* h() {
+>h : () => IterableIterator<any>
+
+    yield undefined;
+>yield undefined : any
+>undefined : undefined
+}
+
diff --git a/tests/baselines/reference/parser.asyncGenerators.classMethods.esnext.types b/tests/baselines/reference/parser.asyncGenerators.classMethods.esnext.types
@@ -140,7 +140,7 @@ class C13 {
 >C13 : C13
 
     async * f() {
->f : () => AsyncIterableIterator<undefined>
+>f : () => AsyncIterableIterator<any>
 
         yield;
 >yield : any
@@ -250,7 +250,7 @@ class C22 {
 >C22 : C22
 
     async * f() {
->f : () => AsyncIterableIterator<undefined>
+>f : () => AsyncIterableIterator<any>
 
         const x = { [yield]: 1 };
 >x : { [x: number]: number; }
diff --git a/tests/baselines/reference/parser.asyncGenerators.functionDeclarations.esnext.types b/tests/baselines/reference/parser.asyncGenerators.functionDeclarations.esnext.types
@@ -88,7 +88,7 @@ async function * f12() {
 }
 === tests/cases/conformance/parser/ecmascriptnext/asyncGenerators/yieldIsOk.ts ===
 async function * f13() {
->f13 : () => AsyncIterableIterator<undefined>
+>f13 : () => AsyncIterableIterator<any>
 
     yield;
 >yield : any
@@ -157,7 +157,7 @@ async function * f20() {
 }
 === tests/cases/conformance/parser/ecmascriptnext/asyncGenerators/yieldInNestedComputedPropertyIsOk.ts ===
 async function * f21() {
->f21 : () => AsyncIterableIterator<undefined>
+>f21 : () => AsyncIterableIterator<any>
 
     const x = { [yield]: 1 };
 >x : { [x: number]: number; }
diff --git a/tests/baselines/reference/parser.asyncGenerators.functionExpressions.esnext.types b/tests/baselines/reference/parser.asyncGenerators.functionExpressions.esnext.types
@@ -113,8 +113,8 @@ const f12 = async function * () {
 };
 === tests/cases/conformance/parser/ecmascriptnext/asyncGenerators/yieldIsOk.ts ===
 const f13 = async function * () {
->f13 : () => AsyncIterableIterator<undefined>
->async function * () {    yield;} : () => AsyncIterableIterator<undefined>
+>f13 : () => AsyncIterableIterator<any>
+>async function * () {    yield;} : () => AsyncIterableIterator<any>
 
     yield;
 >yield : any
@@ -198,8 +198,8 @@ const f20 = async function * () {
 };
 === tests/cases/conformance/parser/ecmascriptnext/asyncGenerators/yieldInNestedComputedPropertyIsOk.ts ===
 const f21 = async function *() {
->f21 : () => AsyncIterableIterator<undefined>
->async function *() {    const x = { [yield]: 1 };} : () => AsyncIterableIterator<undefined>
+>f21 : () => AsyncIterableIterator<any>
+>async function *() {    const x = { [yield]: 1 };} : () => AsyncIterableIterator<any>
 
     const x = { [yield]: 1 };
 >x : { [x: number]: number; }
diff --git a/tests/baselines/reference/parser.asyncGenerators.objectLiteralMethods.esnext.types b/tests/baselines/reference/parser.asyncGenerators.objectLiteralMethods.esnext.types
@@ -151,11 +151,11 @@ const o12 = {
 };
 === tests/cases/conformance/parser/ecmascriptnext/asyncGenerators/yieldIsOk.ts ===
 const o13 = {
->o13 : { f(): AsyncIterableIterator<undefined>; }
->{    async * f() {        yield;    }} : { f(): AsyncIterableIterator<undefined>; }
+>o13 : { f(): AsyncIterableIterator<any>; }
+>{    async * f() {        yield;    }} : { f(): AsyncIterableIterator<any>; }
 
     async * f() {
->f : () => AsyncIterableIterator<undefined>
+>f : () => AsyncIterableIterator<any>
 
         yield;
 >yield : any
@@ -260,11 +260,11 @@ const o20 = {
 };
 === tests/cases/conformance/parser/ecmascriptnext/asyncGenerators/yieldInNestedComputedPropertyIsOk.ts ===
 const o21 = {
->o21 : { f(): AsyncIterableIterator<undefined>; }
->{    async * f() {        const x = { [yield]: 1 };    }} : { f(): AsyncIterableIterator<undefined>; }
+>o21 : { f(): AsyncIterableIterator<any>; }
+>{    async * f() {        const x = { [yield]: 1 };    }} : { f(): AsyncIterableIterator<any>; }
 
     async * f() {
->f : () => AsyncIterableIterator<undefined>
+>f : () => AsyncIterableIterator<any>
 
         const x = { [yield]: 1 };
 >x : { [x: number]: number; }
diff --git a/tests/baselines/reference/types.asyncGenerators.esnext.1.types b/tests/baselines/reference/types.asyncGenerators.esnext.1.types
@@ -3,7 +3,7 @@ async function * inferReturnType1() {
 >inferReturnType1 : () => AsyncIterableIterator<any>
 }
 async function * inferReturnType2() {
->inferReturnType2 : () => AsyncIterableIterator<undefined>
+>inferReturnType2 : () => AsyncIterableIterator<any>
 
     yield;
 >yield : any
diff --git a/tests/cases/conformance/es6/yieldExpressions/generatorTypeCheck48.ts b/tests/cases/conformance/es6/yieldExpressions/generatorTypeCheck48.ts
@@ -3,4 +3,8 @@
 
 function* g() {
     yield;
-}
+}
+
+function* h() {
+    yield undefined;
+}

Original file line number	Diff line number	Diff line change
`@@ -4,7 +4,7 @@ async function * f1() {`
`4`	`4`	`}`
`5`	`5`	`=== tests/cases/conformance/emitter/es2015/asyncGenerators/F2.ts ===`
`6`	`6`	`async function * f2() {`
`7`		`->f2 : () => AsyncIterableIterator<undefined>`
	`7`	`+>f2 : () => AsyncIterableIterator<any>`
`8`	`8`
`9`	`9`	`const x = yield;`
`10`	`10`	`>x : any`
Original file line number	Diff line number	Diff line change
`@@ -4,7 +4,7 @@ async function * f1() {`
`4`	`4`	`}`
`5`	`5`	`=== tests/cases/conformance/emitter/es5/asyncGenerators/F2.ts ===`
`6`	`6`	`async function * f2() {`
`7`		`->f2 : () => AsyncIterableIterator<undefined>`
	`7`	`+>f2 : () => AsyncIterableIterator<any>`
`8`	`8`
`9`	`9`	`const x = yield;`
`10`	`10`	`>x : any`