Merge pull request #3897 from Microsoft/errorForUseSuperInNullExtension

Error for use super in null extension

src/compiler/checker.ts

@@ -10431,9 +10431,17 @@ namespace ts {
             // TS 1.0 spec (April 2014): 8.3.2
             // Constructors of classes with no extends clause may not contain super calls, whereas
             // constructors of derived classes must contain at least one super call somewhere in their function body.
-            if (getClassExtendsHeritageClauseElement(<ClassDeclaration>node.parent)) {
+            let containingClassDecl = <ClassDeclaration>node.parent;
+            if (getClassExtendsHeritageClauseElement(containingClassDecl)) {
+                let containingClassSymbol = getSymbolOfNode(containingClassDecl);
+                let containingClassInstanceType = <InterfaceType>getDeclaredTypeOfSymbol(containingClassSymbol);
+                let baseConstructorType = getBaseConstructorTypeOfClass(containingClassInstanceType);
 
                 if (containsSuperCall(node.body)) {
+                    if (baseConstructorType === nullType) {
+                        error(node, Diagnostics.A_constructor_cannot_contain_a_super_call_when_its_class_extends_null);
+                    }
+
                     // The first statement in the body of a constructor (excluding prologue directives) must be a super call
                     // if both of the following are true:
                     // - The containing class is a derived class.
@@ -10466,7 +10474,7 @@ namespace ts {
                         }
                     }
                 }
-                else {
+                else if (baseConstructorType !== nullType) {
                     error(node, Diagnostics.Constructors_for_derived_classes_must_contain_a_super_call);
                 }
             }

src/compiler/diagnosticInformationMap.generated.ts

@@ -614,5 +614,6 @@ namespace ts {
         Expected_corresponding_JSX_closing_tag_for_0: { code: 17002, category: DiagnosticCategory.Error, key: "Expected corresponding JSX closing tag for '{0}'." },
         JSX_attribute_expected: { code: 17003, category: DiagnosticCategory.Error, key: "JSX attribute expected." },
         Cannot_use_JSX_unless_the_jsx_flag_is_provided: { code: 17004, category: DiagnosticCategory.Error, key: "Cannot use JSX unless the '--jsx' flag is provided." },
+        A_constructor_cannot_contain_a_super_call_when_its_class_extends_null: { code: 17005, category: DiagnosticCategory.Error, key: "A constructor cannot contain a 'super' call when its class extends 'null'" },
     };
 }

src/compiler/diagnosticMessages.json

@@ -1,4 +1,4 @@
-{
+ {
     "Unterminated string literal.": {
         "category": "Error",
         "code": 1002
@@ -2449,5 +2449,9 @@
     "Cannot use JSX unless the '--jsx' flag is provided.": {
         "category": "Error",
         "code": 17004
+    },
+    "A constructor cannot contain a 'super' call when its class extends 'null'": {
+      "category": "Error",
+      "code": 17005
     }
 }

src/compiler/types.ts

@@ -1777,10 +1777,10 @@ namespace ts {
         StringLike = String | StringLiteral,
         NumberLike = Number | Enum,
         ObjectType = Class | Interface | Reference | Tuple | Anonymous,
-        UnionOrIntersection = Union | Intersection,
+        UnionOrIntersection = Union | Intersection,
         StructuredType = ObjectType | Union | Intersection,
         /* @internal */
-        RequiresWidening = ContainsUndefinedOrNull | ContainsObjectLiteral
+        RequiresWidening = ContainsUndefinedOrNull | ContainsObjectLiteral
     }
 
     // Properties common to all types

tests/baselines/reference/classExtendsNull.errors.txt

@@ -0,0 +1,21 @@
+tests/cases/compiler/classExtendsNull.ts(2,5): error TS17005: A constructor cannot contain a 'super' call when its class extends 'null'
+
+
+==== tests/cases/compiler/classExtendsNull.ts (1 errors) ====
+    class C extends null {
+        constructor() {
+        ~~~~~~~~~~~~~~~
+            super();
+    ~~~~~~~~~~~~~~~~
+            return Object.create(null);
+    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+        }
+    ~~~~~
+!!! error TS17005: A constructor cannot contain a 'super' call when its class extends 'null'
+    }
+    
+    class D extends null {
+        constructor() {
+            return Object.create(null);
+        }
+    }

tests/baselines/reference/classExtendsNull.js

@@ -0,0 +1,35 @@
+//// [classExtendsNull.ts]
+class C extends null {
+    constructor() {
+        super();
+        return Object.create(null);
+    }
+}
+
+class D extends null {
+    constructor() {
+        return Object.create(null);
+    }
+}
+
+//// [classExtendsNull.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 C = (function (_super) {
+    __extends(C, _super);
+    function C() {
+        _super.call(this);
+        return Object.create(null);
+    }
+    return C;
+})(null);
+var D = (function (_super) {
+    __extends(D, _super);
+    function D() {
+        return Object.create(null);
+    }
+    return D;
+})(null);

tests/cases/compiler/classExtendsNull.ts

@@ -0,0 +1,12 @@
+class C extends null {
+    constructor() {
+        super();
+        return Object.create(null);
+    }
+}
+
+class D extends null {
+    constructor() {
+        return Object.create(null);
+    }
+}