Address PR

Author: Kanchalai Tanglertsampan

src/compiler/checker.ts

@@ -11766,10 +11766,6 @@ namespace ts {
                 return;
             }
 
-            function isSuperCallExpression(n: Node): boolean {
-                return n.kind === SyntaxKind.CallExpression && (<CallExpression>n).expression.kind === SyntaxKind.SuperKeyword;
-            }
-
             function containsSuperCallAsComputedPropertyName(n: Declaration): boolean {
                 return n.name && containsSuperCall(n.name);
             }

src/compiler/emitter.ts

@@ -4768,21 +4768,22 @@ const _super = (function (geti, seti) {
 
             /**
              * Return the statement at a given index if it is a super-call statement
-             * @param ctor constructor declaration
+             * @param ctor a constructor declaration
              * @param index an index to constructor's body to check
              */
             function getSuperCallAtGivenIndex(ctor: ConstructorDeclaration, index: number): ExpressionStatement {
-                if (ctor.body) {
-                    const statement = (<Block>ctor.body).statements[index];
-                    if (statement && statement.kind === SyntaxKind.ExpressionStatement) {
-                        const expr = (<ExpressionStatement>statement).expression;
-                        if (expr && expr.kind === SyntaxKind.CallExpression) {
-                            const func = (<CallExpression>expr).expression;
-                            if (func && func.kind === SyntaxKind.SuperKeyword) {
-                                return <ExpressionStatement>statement;
-                            }
-                        }
-                    }
+                if (!ctor.body) {
+                    return undefined;
+                }
+                const statements = ctor.body.statements;
+
+                if (!statements || index >= statements.length) {
+                    return undefined;
+                }
+
+                const statement = statements[index];
+                if (statement.kind === SyntaxKind.ExpressionStatement) {
+                    return isSuperCallExpression((<ExpressionStatement>statement).expression) ? <ExpressionStatement>statement : undefined;
                 }
             }
 

src/compiler/utilities.ts

@@ -464,6 +464,10 @@ namespace ts {
         return !!(getCombinedNodeFlags(node) & NodeFlags.Let);
     }
 
+    export function isSuperCallExpression(n: Node): boolean {
+        return n.kind === SyntaxKind.CallExpression && (<CallExpression>n).expression.kind === SyntaxKind.SuperKeyword;
+    }
+
     export function isPrologueDirective(node: Node): boolean {
         return node.kind === SyntaxKind.ExpressionStatement && (<ExpressionStatement>node).expression.kind === SyntaxKind.StringLiteral;
     }