From 37f5e411db8a399175ef50efaa696f03d92b21be Mon Sep 17 00:00:00 2001
From: Jason Freeman <jfreeman@microsoft.com>
Date: Thu, 30 Apr 2015 19:32:23 -0700
Subject: [PATCH] Remove error for having return expressions in a generator

---
 src/compiler/checker.ts                       | 26 +++++++++++--------
 .../diagnosticInformationMap.generated.ts     |  5 ++--
 src/compiler/diagnosticMessages.json          |  8 ++----
 3 files changed, 19 insertions(+), 20 deletions(-)

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index b733457923b..3c637b03f19 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -9822,21 +9822,25 @@ module ts {
                 if (func) {
                     let returnType = getReturnTypeOfSignature(getSignatureFromDeclaration(func));
                     let exprType = checkExpressionCached(node.expression);
+                    
+                    if (func.asteriskToken) {
+                        // A generator does not need its return expressions checked against its return type.
+                        // Instead, the yield expressions are checked against the element type.
+                        // TODO: Check return expressions of generators when return type tracking is added
+                        // for generators.
+                        return;
+                    }
+
                     if (func.kind === SyntaxKind.SetAccessor) {
                         error(node.expression, Diagnostics.Setters_cannot_return_a_value);
                     }
-                    else if (func.asteriskToken) {
-                        error(node.expression, Diagnostics.A_return_statement_cannot_specify_a_value_in_a_generator_function);
+                    else if (func.kind === SyntaxKind.Constructor) {
+                        if (!isTypeAssignableTo(exprType, returnType)) {
+                            error(node.expression, Diagnostics.Return_type_of_constructor_signature_must_be_assignable_to_the_instance_type_of_the_class);
+                        }
                     }
-                    else {
-                        if (func.kind === SyntaxKind.Constructor) {
-                            if (!isTypeAssignableTo(exprType, returnType)) {
-                                error(node.expression, Diagnostics.Return_type_of_constructor_signature_must_be_assignable_to_the_instance_type_of_the_class);
-                            }
-                        }
-                        else if (func.type || isGetAccessorWithAnnotatatedSetAccessor(func)) {
-                            checkTypeAssignableTo(exprType, returnType, node.expression, /*headMessage*/ undefined);
-                        }
+                    else if (func.type || isGetAccessorWithAnnotatatedSetAccessor(func)) {
+                        checkTypeAssignableTo(exprType, returnType, node.expression, /*headMessage*/ undefined);
                     }
                 }
             }
diff --git a/src/compiler/diagnosticInformationMap.generated.ts b/src/compiler/diagnosticInformationMap.generated.ts
index 2332e520ba2..1776f185a9b 100644
--- a/src/compiler/diagnosticInformationMap.generated.ts
+++ b/src/compiler/diagnosticInformationMap.generated.ts
@@ -366,9 +366,8 @@ module ts {
         An_interface_can_only_extend_an_identifier_Slashqualified_name_with_optional_type_arguments: { code: 2499, category: DiagnosticCategory.Error, key: "An interface can only extend an identifier/qualified-name with optional type arguments." },
         A_class_can_only_implement_an_identifier_Slashqualified_name_with_optional_type_arguments: { code: 2500, category: DiagnosticCategory.Error, key: "A class can only implement an identifier/qualified-name with optional type arguments." },
         A_rest_element_cannot_contain_a_binding_pattern: { code: 2501, category: DiagnosticCategory.Error, key: "A rest element cannot contain a binding pattern." },
-        A_return_statement_cannot_specify_a_value_in_a_generator_function: { code: 2502, category: DiagnosticCategory.Error, key: "A return statement cannot specify a value in a generator function." },
-        No_best_common_type_exists_among_yield_expressions: { code: 2503, category: DiagnosticCategory.Error, key: "No best common type exists among yield expressions." },
-        A_generator_cannot_have_a_void_type_annotation: { code: 2504, category: DiagnosticCategory.Error, key: "A generator cannot have a 'void' type annotation." },
+        No_best_common_type_exists_among_yield_expressions: { code: 2502, category: DiagnosticCategory.Error, key: "No best common type exists among yield expressions." },
+        A_generator_cannot_have_a_void_type_annotation: { code: 2503, category: DiagnosticCategory.Error, key: "A generator cannot have a 'void' type annotation." },
         Import_declaration_0_is_using_private_name_1: { code: 4000, category: DiagnosticCategory.Error, key: "Import declaration '{0}' is using private name '{1}'." },
         Type_parameter_0_of_exported_class_has_or_is_using_private_name_1: { code: 4002, category: DiagnosticCategory.Error, key: "Type parameter '{0}' of exported class has or is using private name '{1}'." },
         Type_parameter_0_of_exported_interface_has_or_is_using_private_name_1: { code: 4004, category: DiagnosticCategory.Error, key: "Type parameter '{0}' of exported interface has or is using private name '{1}'." },
diff --git a/src/compiler/diagnosticMessages.json b/src/compiler/diagnosticMessages.json
index 3ce59b552b1..7a1f8a3e728 100644
--- a/src/compiler/diagnosticMessages.json
+++ b/src/compiler/diagnosticMessages.json
@@ -1453,17 +1453,13 @@
         "category": "Error",
         "code": 2501
     },
-    "A return statement cannot specify a value in a generator function.": {
+    "No best common type exists among yield expressions.": {
         "category": "Error",
         "code": 2502
     },
-    "No best common type exists among yield expressions.": {
-        "category": "Error",
-        "code": 2503
-    },
     "A generator cannot have a 'void' type annotation.": {
         "category": "Error",
-        "code": 2504
+        "code": 2503
     },
 
     "Import declaration '{0}' is using private name '{1}'.": {