Merge pull request #4501 from Microsoft/checkClassExpressions

Properly check expressions in class extends clause

Author: ahejlsberg

src/compiler/checker.ts

@@ -12614,6 +12614,7 @@ namespace ts {
                 if (baseTypes.length && produceDiagnostics) {
                     let baseType = baseTypes[0];
                     let staticBaseType = getBaseConstructorTypeOfClass(type);
+                    checkSourceElement(baseTypeNode.expression);
                     if (baseTypeNode.typeArguments) {
                         forEach(baseTypeNode.typeArguments, checkSourceElement);
                         for (let constructor of getConstructorsForTypeArguments(staticBaseType, baseTypeNode.typeArguments)) {
@@ -13683,6 +13684,8 @@ namespace ts {
                 case SyntaxKind.VariableDeclaration:
                 case SyntaxKind.VariableDeclarationList:
                 case SyntaxKind.ClassDeclaration:
+                case SyntaxKind.HeritageClause:
+                case SyntaxKind.ExpressionWithTypeArguments:
                 case SyntaxKind.EnumDeclaration:
                 case SyntaxKind.EnumMember:
                 case SyntaxKind.ExportAssignment:

tests/baselines/reference/missingPropertiesOfClassExpression.errors.txt

@@ -0,0 +1,12 @@
+tests/cases/compiler/missingPropertiesOfClassExpression.ts(1,52): error TS2339: Property 'y' does not exist on type '(Anonymous class)'.
+
+
+==== tests/cases/compiler/missingPropertiesOfClassExpression.ts (1 errors) ====
+    class George extends class { reset() { return this.y; } } {
+                                                       ~
+!!! error TS2339: Property 'y' does not exist on type '(Anonymous class)'.
+        constructor() {
+            super();
+        }
+    }
+    

tests/baselines/reference/missingPropertiesOfClassExpression.js

@@ -0,0 +1,26 @@
+//// [missingPropertiesOfClassExpression.ts]
+class George extends class { reset() { return this.y; } } {
+    constructor() {
+        super();
+    }
+}
+
+
+//// [missingPropertiesOfClassExpression.js]
+var __extends = (this && this.__extends) || function (d, b) {
+    for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
+    function __() { this.constructor = d; }
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
+};
+var George = (function (_super) {
+    __extends(George, _super);
+    function George() {
+        _super.call(this);
+    }
+    return George;
+})((function () {
+    function class_1() {
+    }
+    class_1.prototype.reset = function () { return this.y; };
+    return class_1;
+})());

tests/cases/compiler/missingPropertiesOfClassExpression.ts

@@ -0,0 +1,5 @@
+class George extends class { reset() { return this.y; } } {
+    constructor() {
+        super();
+    }
+}