inherit default constructor even if type arguments are less than base class type parameter count

src/compiler/checker.ts

@@ -1,4 +1,4 @@
-/// <reference path="moduleNameResolver.ts"/>
+/// <reference path="moduleNameResolver.ts"/>
 /// <reference path="binder.ts"/>
 
 /* @internal */
@@ -3986,16 +3986,13 @@ namespace ts {
         function getConstructorsForTypeArguments(type: Type, typeArgumentNodes: TypeNode[]): Signature[] {
             const typeArgCount = length(typeArgumentNodes);
             return filter(getSignaturesOfType(type, SignatureKind.Construct),
-                sig => typeArgCount >= getMinTypeArgumentCount(sig.typeParameters) && typeArgCount <= length(sig.typeParameters));
+                sig => typeArgCount <= length(sig.typeParameters));
         }
 
         function getInstantiatedConstructorsForTypeArguments(type: Type, typeArgumentNodes: TypeNode[]): Signature[] {
             let signatures = getConstructorsForTypeArguments(type, typeArgumentNodes);
-            if (typeArgumentNodes) {
-                const typeArguments = map(typeArgumentNodes, getTypeFromTypeNode);
-                signatures = map(signatures, sig => getSignatureInstantiation(sig, typeArguments));
-            }
-            return signatures;
+            const typeArguments = length(typeArgumentNodes) ? map(typeArgumentNodes, getTypeFromTypeNode): undefined
+            return signatures && map(signatures, sig => length(sig.typeParameters) ? getSignatureInstantiation(sig, typeArguments) : sig);
         }
 
         /**
@@ -4587,9 +4584,8 @@ namespace ts {
             const typeArgCount = length(typeArguments);
             const result: Signature[] = [];
             for (const baseSig of baseSignatures) {
-                const minTypeArgumentCount = getMinTypeArgumentCount(baseSig.typeParameters);
                 const typeParamCount = length(baseSig.typeParameters);
-                if (typeArgCount >= minTypeArgumentCount && typeArgCount <= typeParamCount) {
+                if (typeArgCount <= typeParamCount) {
                     const sig = typeParamCount ? createSignatureInstantiation(baseSig, fillMissingTypeArguments(typeArguments, baseSig.typeParameters, /*errorNode*/ undefined)) : cloneSignature(baseSig);
                     sig.typeParameters = classType.localTypeParameters;
                     sig.resolvedReturnType = classType;

tests/baselines/reference/classExtendingClassLikeType.errors.txt

@@ -1,9 +1,11 @@
 tests/cases/conformance/classes/classDeclarations/classExtendingClassLikeType.ts(7,18): error TS2689: Cannot extend an interface 'Base'. Did you mean 'implements'?
+tests/cases/conformance/classes/classDeclarations/classExtendingClassLikeType.ts(19,18): error TS2510: Base constructors must all have the same return type.
+tests/cases/conformance/classes/classDeclarations/classExtendingClassLikeType.ts(27,18): error TS2510: Base constructors must all have the same return type.
 tests/cases/conformance/classes/classDeclarations/classExtendingClassLikeType.ts(45,18): error TS2508: No base constructor has the specified number of type arguments.
 tests/cases/conformance/classes/classDeclarations/classExtendingClassLikeType.ts(56,18): error TS2510: Base constructors must all have the same return type.
 
 
-==== tests/cases/conformance/classes/classDeclarations/classExtendingClassLikeType.ts (3 errors) ====
+==== tests/cases/conformance/classes/classDeclarations/classExtendingClassLikeType.ts (5 errors) ====
     interface Base<T, U> {
         x: T;
         y: U;
@@ -25,6 +27,8 @@ tests/cases/conformance/classes/classDeclarations/classExtendingClassLikeType.ts
     declare function getBase(): BaseConstructor;
 
     class D1 extends getBase() {
+                     ~~~~~~~~~
+!!! error TS2510: Base constructors must all have the same return type.
         constructor() {
             super("abc", "def");
             this.x = "x";
@@ -33,6 +37,8 @@ tests/cases/conformance/classes/classDeclarations/classExtendingClassLikeType.ts
     }
 
     class D2 extends getBase() <number> {
+                     ~~~~~~~~~
+!!! error TS2510: Base constructors must all have the same return type.
         constructor() {
             super(10);
             super(10, 20);

tests/baselines/reference/extendingFromGenericTypeWithMissingTypeArguments.js

@@ -0,0 +1,68 @@
+//// [extendingFromGenericTypeWithMissingTypeArguments.ts]
+class C1<T> {
+    c1_prop: T;
+}
+class D1 extends C1 {
+    d1_prop: number;
+}
+
+var d1 = new D1();
+d1.c1_prop; // any
+d1.d1_prop;
+
+
+class C2<T> {
+    constructor(a: T) { }
+    c1_prop: T;
+}
+class D2 extends C2 {
+    d1_prop: number;
+}
+
+var d1 = new D2(2);
+d1.c1_prop; // any
+d1.d1_prop;
+
+
+
+//// [extendingFromGenericTypeWithMissingTypeArguments.js]
+var __extends = (this && this.__extends) || (function () {
+    var extendStatics = Object.setPrototypeOf ||
+        ({ __proto__: [] } instanceof Array && function (d, b) { d.__proto__ = b; }) ||
+        function (d, b) { for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p]; };
+    return function (d, b) {
+        extendStatics(d, b);
+        function __() { this.constructor = d; }
+        d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
+    };
+})();
+var C1 = (function () {
+    function C1() {
+    }
+    return C1;
+}());
+var D1 = (function (_super) {
+    __extends(D1, _super);
+    function D1() {
+        return _super !== null && _super.apply(this, arguments) || this;
+    }
+    return D1;
+}(C1));
+var d1 = new D1();
+d1.c1_prop; // any
+d1.d1_prop;
+var C2 = (function () {
+    function C2(a) {
+    }
+    return C2;
+}());
+var D2 = (function (_super) {
+    __extends(D2, _super);
+    function D2() {
+        return _super !== null && _super.apply(this, arguments) || this;
+    }
+    return D2;
+}(C2));
+var d1 = new D2(2);
+d1.c1_prop; // any
+d1.d1_prop;

tests/baselines/reference/extendingFromGenericTypeWithMissingTypeArguments.symbols

@@ -0,0 +1,67 @@
+=== tests/cases/compiler/extendingFromGenericTypeWithMissingTypeArguments.ts ===
+class C1<T> {
+>C1 : Symbol(C1, Decl(extendingFromGenericTypeWithMissingTypeArguments.ts, 0, 0))
+>T : Symbol(T, Decl(extendingFromGenericTypeWithMissingTypeArguments.ts, 0, 9))
+
+    c1_prop: T;
+>c1_prop : Symbol(C1.c1_prop, Decl(extendingFromGenericTypeWithMissingTypeArguments.ts, 0, 13))
+>T : Symbol(T, Decl(extendingFromGenericTypeWithMissingTypeArguments.ts, 0, 9))
+}
+class D1 extends C1 {
+>D1 : Symbol(D1, Decl(extendingFromGenericTypeWithMissingTypeArguments.ts, 2, 1))
+>C1 : Symbol(C1, Decl(extendingFromGenericTypeWithMissingTypeArguments.ts, 0, 0))
+
+    d1_prop: number;
+>d1_prop : Symbol(D1.d1_prop, Decl(extendingFromGenericTypeWithMissingTypeArguments.ts, 3, 21))
+}
+
+var d1 = new D1();
+>d1 : Symbol(d1, Decl(extendingFromGenericTypeWithMissingTypeArguments.ts, 7, 3), Decl(extendingFromGenericTypeWithMissingTypeArguments.ts, 20, 3))
+>D1 : Symbol(D1, Decl(extendingFromGenericTypeWithMissingTypeArguments.ts, 2, 1))
+
+d1.c1_prop; // any
+>d1.c1_prop : Symbol(C1.c1_prop, Decl(extendingFromGenericTypeWithMissingTypeArguments.ts, 0, 13))
+>d1 : Symbol(d1, Decl(extendingFromGenericTypeWithMissingTypeArguments.ts, 7, 3), Decl(extendingFromGenericTypeWithMissingTypeArguments.ts, 20, 3))
+>c1_prop : Symbol(C1.c1_prop, Decl(extendingFromGenericTypeWithMissingTypeArguments.ts, 0, 13))
+
+d1.d1_prop;
+>d1.d1_prop : Symbol(D1.d1_prop, Decl(extendingFromGenericTypeWithMissingTypeArguments.ts, 3, 21))
+>d1 : Symbol(d1, Decl(extendingFromGenericTypeWithMissingTypeArguments.ts, 7, 3), Decl(extendingFromGenericTypeWithMissingTypeArguments.ts, 20, 3))
+>d1_prop : Symbol(D1.d1_prop, Decl(extendingFromGenericTypeWithMissingTypeArguments.ts, 3, 21))
+
+
+class C2<T> {
+>C2 : Symbol(C2, Decl(extendingFromGenericTypeWithMissingTypeArguments.ts, 9, 11))
+>T : Symbol(T, Decl(extendingFromGenericTypeWithMissingTypeArguments.ts, 12, 9))
+
+    constructor(a: T) { }
+>a : Symbol(a, Decl(extendingFromGenericTypeWithMissingTypeArguments.ts, 13, 16))
+>T : Symbol(T, Decl(extendingFromGenericTypeWithMissingTypeArguments.ts, 12, 9))
+
+    c1_prop: T;
+>c1_prop : Symbol(C2.c1_prop, Decl(extendingFromGenericTypeWithMissingTypeArguments.ts, 13, 25))
+>T : Symbol(T, Decl(extendingFromGenericTypeWithMissingTypeArguments.ts, 12, 9))
+}
+class D2 extends C2 {
+>D2 : Symbol(D2, Decl(extendingFromGenericTypeWithMissingTypeArguments.ts, 15, 1))
+>C2 : Symbol(C2, Decl(extendingFromGenericTypeWithMissingTypeArguments.ts, 9, 11))
+
+    d1_prop: number;
+>d1_prop : Symbol(D2.d1_prop, Decl(extendingFromGenericTypeWithMissingTypeArguments.ts, 16, 21))
+}
+
+var d1 = new D2(2);
+>d1 : Symbol(d1, Decl(extendingFromGenericTypeWithMissingTypeArguments.ts, 7, 3), Decl(extendingFromGenericTypeWithMissingTypeArguments.ts, 20, 3))
+>D2 : Symbol(D2, Decl(extendingFromGenericTypeWithMissingTypeArguments.ts, 15, 1))
+
+d1.c1_prop; // any
+>d1.c1_prop : Symbol(C1.c1_prop, Decl(extendingFromGenericTypeWithMissingTypeArguments.ts, 0, 13))
+>d1 : Symbol(d1, Decl(extendingFromGenericTypeWithMissingTypeArguments.ts, 7, 3), Decl(extendingFromGenericTypeWithMissingTypeArguments.ts, 20, 3))
+>c1_prop : Symbol(C1.c1_prop, Decl(extendingFromGenericTypeWithMissingTypeArguments.ts, 0, 13))
+
+d1.d1_prop;
+>d1.d1_prop : Symbol(D1.d1_prop, Decl(extendingFromGenericTypeWithMissingTypeArguments.ts, 3, 21))
+>d1 : Symbol(d1, Decl(extendingFromGenericTypeWithMissingTypeArguments.ts, 7, 3), Decl(extendingFromGenericTypeWithMissingTypeArguments.ts, 20, 3))
+>d1_prop : Symbol(D1.d1_prop, Decl(extendingFromGenericTypeWithMissingTypeArguments.ts, 3, 21))
+
+

tests/baselines/reference/extendingFromGenericTypeWithMissingTypeArguments.types

@@ -0,0 +1,70 @@
+=== tests/cases/compiler/extendingFromGenericTypeWithMissingTypeArguments.ts ===
+class C1<T> {
+>C1 : C1<T>
+>T : T
+
+    c1_prop: T;
+>c1_prop : T
+>T : T
+}
+class D1 extends C1 {
+>D1 : D1
+>C1 : C1<any>
+
+    d1_prop: number;
+>d1_prop : number
+}
+
+var d1 = new D1();
+>d1 : D1
+>new D1() : D1
+>D1 : typeof D1
+
+d1.c1_prop; // any
+>d1.c1_prop : any
+>d1 : D1
+>c1_prop : any
+
+d1.d1_prop;
+>d1.d1_prop : number
+>d1 : D1
+>d1_prop : number
+
+
+class C2<T> {
+>C2 : C2<T>
+>T : T
+
+    constructor(a: T) { }
+>a : T
+>T : T
+
+    c1_prop: T;
+>c1_prop : T
+>T : T
+}
+class D2 extends C2 {
+>D2 : D2
+>C2 : C2<any>
+
+    d1_prop: number;
+>d1_prop : number
+}
+
+var d1 = new D2(2);
+>d1 : D1
+>new D2(2) : D2
+>D2 : typeof D2
+>2 : 2
+
+d1.c1_prop; // any
+>d1.c1_prop : any
+>d1 : D1
+>c1_prop : any
+
+d1.d1_prop;
+>d1.d1_prop : number
+>d1 : D1
+>d1_prop : number
+
+

tests/baselines/reference/recursiveBaseConstructorCreation3.errors.txt

@@ -1,8 +1,7 @@
 tests/cases/compiler/recursiveBaseConstructorCreation3.ts(6,27): error TS2707: Type parameter 'T' implicitly has type 'any' because it was not supplied.
-tests/cases/compiler/recursiveBaseConstructorCreation3.ts(9,11): error TS2351: Cannot use 'new' with an expression whose type lacks a call or construct signature.
 
 
-==== tests/cases/compiler/recursiveBaseConstructorCreation3.ts (2 errors) ====
+==== tests/cases/compiler/recursiveBaseConstructorCreation3.ts (1 errors) ====
     declare class base<T> {
     }
     declare class abc<T> extends base<T> {
@@ -13,7 +12,5 @@ tests/cases/compiler/recursiveBaseConstructorCreation3.ts(9,11): error TS2351: C
 !!! error TS2707: Type parameter 'T' implicitly has type 'any' because it was not supplied.
     }
 
-    var bar = new xyz(); // Error: Invalid 'new' expression.
-              ~~~~~~~~~
-!!! error TS2351: Cannot use 'new' with an expression whose type lacks a call or construct signature.
+    var bar = new xyz();
     var r: xyz = bar.foo;

tests/baselines/reference/recursiveBaseConstructorCreation3.js

@@ -7,9 +7,9 @@ declare class abc<T> extends base<T> {
 declare class xyz extends abc {
 }
 
-var bar = new xyz(); // Error: Invalid 'new' expression.
+var bar = new xyz();
 var r: xyz = bar.foo;
 
 //// [recursiveBaseConstructorCreation3.js]
-var bar = new xyz(); // Error: Invalid 'new' expression.
+var bar = new xyz();
 var r = bar.foo;

tests/baselines/reference/superCallFromClassThatDerivesFromGenericTypeButWithIncorrectNumberOfTypeArguments1.errors.txt

@@ -1,9 +1,7 @@
 tests/cases/compiler/superCallFromClassThatDerivesFromGenericTypeButWithIncorrectNumberOfTypeArguments1.ts(8,17): error TS2707: Type parameter 'T2' implicitly has type 'any' because it was not supplied.
-tests/cases/compiler/superCallFromClassThatDerivesFromGenericTypeButWithIncorrectNumberOfTypeArguments1.ts(9,21): error TS2346: Supplied parameters do not match any signature of call target.
-tests/cases/compiler/superCallFromClassThatDerivesFromGenericTypeButWithIncorrectNumberOfTypeArguments1.ts(9,27): error TS7006: Parameter 'value' implicitly has an 'any' type.
 
 
-==== tests/cases/compiler/superCallFromClassThatDerivesFromGenericTypeButWithIncorrectNumberOfTypeArguments1.ts (3 errors) ====
+==== tests/cases/compiler/superCallFromClassThatDerivesFromGenericTypeButWithIncorrectNumberOfTypeArguments1.ts (1 errors) ====
 
     class A<T1, T2> {
         constructor(private map: (value: T1) => T2) {
@@ -15,8 +13,4 @@ tests/cases/compiler/superCallFromClassThatDerivesFromGenericTypeButWithIncorrec
                     ~~~~~~~~~
 !!! error TS2707: Type parameter 'T2' implicitly has type 'any' because it was not supplied.
         constructor() { super(value => String(value)); }
-                        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-!!! error TS2346: Supplied parameters do not match any signature of call target.
-                              ~~~~~
-!!! error TS7006: Parameter 'value' implicitly has an 'any' type.
     }

tests/baselines/reference/superCallFromClassThatDerivesFromGenericTypeButWithNoTypeArguments1.errors.txt

@@ -1,10 +1,8 @@
 tests/cases/compiler/superCallFromClassThatDerivesFromGenericTypeButWithNoTypeArguments1.ts(8,17): error TS2707: Type parameter 'T1' implicitly has type 'any' because it was not supplied.
 tests/cases/compiler/superCallFromClassThatDerivesFromGenericTypeButWithNoTypeArguments1.ts(8,17): error TS2707: Type parameter 'T2' implicitly has type 'any' because it was not supplied.
-tests/cases/compiler/superCallFromClassThatDerivesFromGenericTypeButWithNoTypeArguments1.ts(9,21): error TS2346: Supplied parameters do not match any signature of call target.
-tests/cases/compiler/superCallFromClassThatDerivesFromGenericTypeButWithNoTypeArguments1.ts(9,27): error TS7006: Parameter 'value' implicitly has an 'any' type.
 
 
-==== tests/cases/compiler/superCallFromClassThatDerivesFromGenericTypeButWithNoTypeArguments1.ts (4 errors) ====
+==== tests/cases/compiler/superCallFromClassThatDerivesFromGenericTypeButWithNoTypeArguments1.ts (2 errors) ====
 
     class A<T1, T2> {
         constructor(private map: (value: T1) => T2) {
@@ -18,8 +16,4 @@ tests/cases/compiler/superCallFromClassThatDerivesFromGenericTypeButWithNoTypeAr
                     ~
 !!! error TS2707: Type parameter 'T2' implicitly has type 'any' because it was not supplied.
         constructor() { super(value => String(value)); }
-                        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-!!! error TS2346: Supplied parameters do not match any signature of call target.
-                              ~~~~~
-!!! error TS7006: Parameter 'value' implicitly has an 'any' type.
     }

tests/cases/compiler/extendingFromGenericTypeWithMissingTypeArguments.ts

@@ -0,0 +1,24 @@
+class C1<T> {
+    c1_prop: T;
+}
+class D1 extends C1 {
+    d1_prop: number;
+}
+
+var d1 = new D1();
+d1.c1_prop; // any
+d1.d1_prop;
+
+
+class C2<T> {
+    constructor(a: T) { }
+    c1_prop: T;
+}
+class D2 extends C2 {
+    d1_prop: number;
+}
+
+var d1 = new D2(2);
+d1.c1_prop; // any
+d1.d1_prop;
+

tests/cases/compiler/recursiveBaseConstructorCreation3.ts

@@ -7,5 +7,5 @@ declare class abc<T> extends base<T> {
 declare class xyz extends abc {
 }
 
-var bar = new xyz(); // Error: Invalid 'new' expression.
+var bar = new xyz();
 var r: xyz = bar.foo;