Merge pull request microsoft#7358 from martine/empty-return

mhegazy · mhegazy · commit 0cba37d5b2cf · 2016-03-03T13:56:19.000-08:00
in noImplicitReturns mode, also disallow "return;"
diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
@@ -13848,11 +13848,11 @@ namespace ts {
                 }
             }
 
-            if (node.expression) {
-                const func = getContainingFunction(node);
-                if (func) {
-                    const signature = getSignatureFromDeclaration(func);
-                    const returnType = getReturnTypeOfSignature(signature);
+            const func = getContainingFunction(node);
+            if (func) {
+                const signature = getSignatureFromDeclaration(func);
+                const returnType = getReturnTypeOfSignature(signature);
+                if (node.expression) {
                     const exprType = checkExpressionCached(node.expression);
 
                     if (func.asteriskToken) {
@@ -13887,6 +13887,10 @@ namespace ts {
                         }
                     }
                 }
+                else if (compilerOptions.noImplicitReturns && !maybeTypeOfKind(returnType, TypeFlags.Void | TypeFlags.Any)) {
+                    // The function has a return type, but the return statement doesn't have an expression.
+                    error(node, Diagnostics.Not_all_code_paths_return_a_value);
+                }
             }
         }
 
diff --git a/tests/baselines/reference/noImplicitReturnsWithoutReturnExpression.errors.txt b/tests/baselines/reference/noImplicitReturnsWithoutReturnExpression.errors.txt
@@ -0,0 +1,34 @@
+tests/cases/compiler/noImplicitReturnsWithoutReturnExpression.ts(2,5): error TS7030: Not all code paths return a value.
+tests/cases/compiler/noImplicitReturnsWithoutReturnExpression.ts(22,9): error TS7030: Not all code paths return a value.
+
+
+==== tests/cases/compiler/noImplicitReturnsWithoutReturnExpression.ts (2 errors) ====
+    function isMissingReturnExpression(): number {
+        return;
+        ~~~~~~~
+!!! error TS7030: Not all code paths return a value.
+    }
+    
+    function isMissingReturnExpression2(): any {
+        return;
+    }
+    
+    function isMissingReturnExpression3(): number|void {
+        return;
+    }
+    
+    function isMissingReturnExpression4(): void {
+        return;
+    }
+    
+    function isMissingReturnExpression5(x) {
+        if (x) {
+            return 0;
+        }
+        else {
+            return;
+            ~~~~~~~
+!!! error TS7030: Not all code paths return a value.
+        }
+    }
+    
diff --git a/tests/baselines/reference/noImplicitReturnsWithoutReturnExpression.js b/tests/baselines/reference/noImplicitReturnsWithoutReturnExpression.js
@@ -0,0 +1,48 @@
+//// [noImplicitReturnsWithoutReturnExpression.ts]
+function isMissingReturnExpression(): number {
+    return;
+}
+
+function isMissingReturnExpression2(): any {
+    return;
+}
+
+function isMissingReturnExpression3(): number|void {
+    return;
+}
+
+function isMissingReturnExpression4(): void {
+    return;
+}
+
+function isMissingReturnExpression5(x) {
+    if (x) {
+        return 0;
+    }
+    else {
+        return;
+    }
+}
+
+
+//// [noImplicitReturnsWithoutReturnExpression.js]
+function isMissingReturnExpression() {
+    return;
+}
+function isMissingReturnExpression2() {
+    return;
+}
+function isMissingReturnExpression3() {
+    return;
+}
+function isMissingReturnExpression4() {
+    return;
+}
+function isMissingReturnExpression5(x) {
+    if (x) {
+        return 0;
+    }
+    else {
+        return;
+    }
+}
diff --git a/tests/cases/compiler/noImplicitReturnsWithoutReturnExpression.ts b/tests/cases/compiler/noImplicitReturnsWithoutReturnExpression.ts
@@ -0,0 +1,25 @@
+// @noImplicitReturns: true
+function isMissingReturnExpression(): number {
+    return;
+}
+
+function isMissingReturnExpression2(): any {
+    return;
+}
+
+function isMissingReturnExpression3(): number|void {
+    return;
+}
+
+function isMissingReturnExpression4(): void {
+    return;
+}
+
+function isMissingReturnExpression5(x) {
+    if (x) {
+        return 0;
+    }
+    else {
+        return;
+    }
+}

Original file line number	Diff line number	Diff line change
`@@ -13848,11 +13848,11 @@ namespace ts {`
`13848`	`13848`	`}`
`13849`	`13849`	`}`
`13850`	`13850`
`13851`		`- if (node.expression) {`
`13852`		`- const func = getContainingFunction(node);`
`13853`		`- if (func) {`
`13854`		`- const signature = getSignatureFromDeclaration(func);`
`13855`		`- const returnType = getReturnTypeOfSignature(signature);`
	`13851`	`+ const func = getContainingFunction(node);`
	`13852`	`+ if (func) {`
	`13853`	`+ const signature = getSignatureFromDeclaration(func);`
	`13854`	`+ const returnType = getReturnTypeOfSignature(signature);`
	`13855`	`+ if (node.expression) {`
`13856`	`13856`	`const exprType = checkExpressionCached(node.expression);`
`13857`	`13857`
`13858`	`13858`	`if (func.asteriskToken) {`
`@@ -13887,6 +13887,10 @@ namespace ts {`
`13887`	`13887`	`}`
`13888`	`13888`	`}`
`13889`	`13889`	`}`
	`13890`	`+ else if (compilerOptions.noImplicitReturns && !maybeTypeOfKind(returnType, TypeFlags.Void \| TypeFlags.Any)) {`
	`13891`	`+ // The function has a return type, but the return statement doesn't have an expression.`
	`13892`	`+ error(node, Diagnostics.Not_all_code_paths_return_a_value);`
	`13893`	`+ }`
`13890`	`13894`	`}`
`13891`	`13895`	`}`
`13892`	`13896`