From 5b98eba3d8e2f7ef0119b14088e6460300e8eaee Mon Sep 17 00:00:00 2001
From: Yui T <yuisu@microsoft.com>
Date: Fri, 12 Dec 2014 15:10:35 -0800
Subject: [PATCH] Address code review; check class heritage clause into its own
 function

---
 src/compiler/checker.ts | 78 ++++++++++++++++++++++-------------------
 1 file changed, 41 insertions(+), 37 deletions(-)

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index a0fde165f66..97c39dd8aaf 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -8263,43 +8263,7 @@ module ts {
 
         function checkClassDeclaration(node: ClassDeclaration) {
             // Grammar checking
-            var seenExtendsClause = false;
-            var seenImplementsClause = false;
-
-            if (!checkGrammarModifiers(node) && node.heritageClauses) {
-                for (var i = 0, n = node.heritageClauses.length; i < n; i++) {
-                    Debug.assert(i <= 2);
-                    var heritageClause = node.heritageClauses[i];
-
-                    if (heritageClause.token === SyntaxKind.ExtendsKeyword) {
-                        if (seenExtendsClause) {
-                            grammarErrorOnFirstToken(heritageClause, Diagnostics.extends_clause_already_seen)
-                            break;
-                        }
-
-                        if (seenImplementsClause) {
-                            grammarErrorOnFirstToken(heritageClause, Diagnostics.extends_clause_must_precede_implements_clause);
-                            break;
-                        }
-
-                        if (heritageClause.types.length > 1) {
-                            grammarErrorOnFirstToken(heritageClause.types[1], Diagnostics.Classes_can_only_extend_a_single_class);
-                            break;
-                        }
-
-                        seenExtendsClause = true;
-                    }
-                    else {
-                        Debug.assert(heritageClause.token === SyntaxKind.ImplementsKeyword);
-                        if (seenImplementsClause) {
-                            grammarErrorOnFirstToken(heritageClause, Diagnostics.implements_clause_already_seen);
-                            break;
-                        }
-
-                        seenImplementsClause = true;
-                    }
-                }
-            }
+            checkGrammarClassDeclarationHeritageClauses(node);
 
             checkTypeNameIsReserved(node.name, Diagnostics.Class_name_cannot_be_0);
             checkTypeParameters(node.typeParameters);
@@ -10044,6 +10008,46 @@ module ts {
             }
         }
 
+        function checkGrammarClassDeclarationHeritageClauses(node: ClassDeclaration) {
+            var seenExtendsClause = false;
+            var seenImplementsClause = false;
+
+            if (!checkGrammarModifiers(node) && node.heritageClauses) {
+                for (var i = 0, n = node.heritageClauses.length; i < n; i++) {
+                    Debug.assert(i <= 2);
+                    var heritageClause = node.heritageClauses[i];
+
+                    if (heritageClause.token === SyntaxKind.ExtendsKeyword) {
+                        if (seenExtendsClause) {
+                            grammarErrorOnFirstToken(heritageClause, Diagnostics.extends_clause_already_seen)
+                            break;
+                        }
+
+                        if (seenImplementsClause) {
+                            grammarErrorOnFirstToken(heritageClause, Diagnostics.extends_clause_must_precede_implements_clause);
+                            break;
+                        }
+
+                        if (heritageClause.types.length > 1) {
+                            grammarErrorOnFirstToken(heritageClause.types[1], Diagnostics.Classes_can_only_extend_a_single_class);
+                            break;
+                        }
+
+                        seenExtendsClause = true;
+                    }
+                    else {
+                        Debug.assert(heritageClause.token === SyntaxKind.ImplementsKeyword);
+                        if (seenImplementsClause) {
+                            grammarErrorOnFirstToken(heritageClause, Diagnostics.implements_clause_already_seen);
+                            break;
+                        }
+
+                        seenImplementsClause = true;
+                    }
+                }
+            }
+        }
+
         function checkGrammarComputedPropertyName(node: ComputedPropertyName): void {
             // Since computed properties are not supported in the type checker, disallow them in TypeScript 1.4
             // Once full support is added, remove this error.