PR feedback

src/compiler/checker.ts

@@ -5368,22 +5368,17 @@ module ts {
                         }
                     }
                 }
-                // Target type is type of constructor signiture
+                // Target type is type of construct signature
                 let constructSignatures: Signature[];
                 if (rightType.flags & TypeFlags.Interface) {
-                    constructSignatures = (<InterfaceTypeWithDeclaredMembers>rightType).declaredConstructSignatures;
+                    constructSignatures = resolveDeclaredMembers(<InterfaceType>rightType).declaredConstructSignatures;
                 }
                 else if (rightType.flags & TypeFlags.Anonymous) {
-                    constructSignatures = (<ResolvedType>rightType).constructSignatures;
+                    constructSignatures = getSignaturesOfType(rightType, SignatureKind.Construct);
                 }
 
-                if (constructSignatures) {
-                    let instanceType = getUnionType(map(constructSignatures, constructSignature => {
-                        if (constructSignature.typeParameters && constructSignature.typeParameters.length !== 0) {
-                            constructSignature = instantiateSignature(constructSignature, createTypeMapper(constructSignature.typeParameters, map(constructSignature.typeParameters, _ => anyType)), true)
-                        }
-                        return constructSignature.resolvedReturnType;
-                    }));
+                if (constructSignatures && constructSignatures.length !== 0) {
+                    let instanceType = getUnionType(map(constructSignatures, signature => getReturnTypeOfSignature(getErasedSignature(signature))));
                     // Pickup type from union types
                     if (type.flags & TypeFlags.Union) {
                         return getUnionTypeOfSubtypeConstituents(<UnionType>type, instanceType);

tests/baselines/reference/typeGuardsWithInstanceOfByConstructorSignature.errors.txt

@@ -1,220 +1,220 @@
-tests/cases/conformance/expressions/typeGuards/typeGuardsWithInstanceOfByConstructorSignature.ts(12,10): error TS2339: Property 'bar' does not exist on type 'A'.
-tests/cases/conformance/expressions/typeGuards/typeGuardsWithInstanceOfByConstructorSignature.ts(33,5): error TS2322: Type 'string' is not assignable to type 'number'.
-tests/cases/conformance/expressions/typeGuards/typeGuardsWithInstanceOfByConstructorSignature.ts(34,10): error TS2339: Property 'bar' does not exist on type 'B<number>'.
-tests/cases/conformance/expressions/typeGuards/typeGuardsWithInstanceOfByConstructorSignature.ts(63,10): error TS2339: Property 'bar2' does not exist on type 'C1'.
-tests/cases/conformance/expressions/typeGuards/typeGuardsWithInstanceOfByConstructorSignature.ts(82,10): error TS2339: Property 'bar' does not exist on type 'D'.
-tests/cases/conformance/expressions/typeGuards/typeGuardsWithInstanceOfByConstructorSignature.ts(109,10): error TS2339: Property 'bar2' does not exist on type 'E1'.
-tests/cases/conformance/expressions/typeGuards/typeGuardsWithInstanceOfByConstructorSignature.ts(131,11): error TS2339: Property 'foo' does not exist on type 'string | F'.
-tests/cases/conformance/expressions/typeGuards/typeGuardsWithInstanceOfByConstructorSignature.ts(132,11): error TS2339: Property 'bar' does not exist on type 'string | F'.
-tests/cases/conformance/expressions/typeGuards/typeGuardsWithInstanceOfByConstructorSignature.ts(157,11): error TS2339: Property 'foo2' does not exist on type 'G1'.
-tests/cases/conformance/expressions/typeGuards/typeGuardsWithInstanceOfByConstructorSignature.ts(179,11): error TS2339: Property 'bar' does not exist on type 'H'.
-
-
-==== tests/cases/conformance/expressions/typeGuards/typeGuardsWithInstanceOfByConstructorSignature.ts (10 errors) ====
-    interface AConstructor {
-        new (): A;
-    }
-    interface A {
-        foo: string;
-    }
-    declare var A: AConstructor;
-    
-    var obj1: A | string;
-    if (obj1 instanceof A) { // narrowed to A.
-        obj1.foo;
-        obj1.bar;
-             ~~~
-!!! error TS2339: Property 'bar' does not exist on type 'A'.
-    }
-    
-    var obj2: any;
-    if (obj2 instanceof A) { // can't type narrowing from any.
-        obj2.foo;
-        obj2.bar;
-    }
-    
-    // a construct signature with generics
-    interface BConstructor {
-        new <T>(): B<T>;
-    }
-    interface B<T> {
-        foo: T;
-    }
-    declare var B: BConstructor;
-    
-    var obj3: B<number> | string;
-    if (obj3 instanceof B) { // narrowed to B<number>.
-        obj3.foo = 1;
-        obj3.foo = "str";
-        ~~~~~~~~
-!!! error TS2322: Type 'string' is not assignable to type 'number'.
-        obj3.bar = "str";
-             ~~~
-!!! error TS2339: Property 'bar' does not exist on type 'B<number>'.
-    }
-    
-    var obj4: any;
-    if (obj4 instanceof B) { // can't type narrowing from any.
-        obj4.foo = "str";
-        obj4.foo = 1;
-        obj4.bar = "str";
-    }
-    
-    // has multiple construct signature
-    interface CConstructor {
-        new (value: string): C1;
-        new (value: number): C2;
-    }
-    interface C1 {
-        foo: string;
-        bar1: number;
-    }
-    interface C2 {
-        foo: string;
-        bar2: number;
-    }
-    declare var C: CConstructor;
-    
-    var obj5: C1 | A;
-    if (obj5 instanceof C) { // narrowed to C1.
-        obj5.foo;
-        obj5.bar1;
-        obj5.bar2;
-             ~~~~
-!!! error TS2339: Property 'bar2' does not exist on type 'C1'.
-    }
-    
-    var obj6: any;
-    if (obj6 instanceof C) { // can't type narrowing from any.
-        obj6.foo;
-        obj6.bar1;
-        obj6.bar2;
-    }
-    
-    // with object type literal
-    interface D {
-        foo: string;
-    }
-    declare var D: { new (): D; };
-    
-    var obj7: D | string;
-    if (obj7 instanceof D) { // narrowed to D.
-        obj7.foo;
-        obj7.bar;
-             ~~~
-!!! error TS2339: Property 'bar' does not exist on type 'D'.
-    }
-    
-    var obj8: any;
-    if (obj8 instanceof D) { // can't type narrowing from any.
-        obj8.foo;
-        obj8.bar;
-    }
-    
-    // a construct signature that returns a union type
-    interface EConstructor {
-        new (): E1 | E2;
-    }
-    interface E1 {
-        foo: string;
-        bar1: number;
-    }
-    interface E2 {
-        foo: string;
-        bar2: number;
-    }
-    declare var E: EConstructor;
-    
-    var obj9: E1 | A;
-    if (obj9 instanceof E) { // narrowed to E1.
-        obj9.foo;
-        obj9.bar1;
-        obj9.bar2;
-             ~~~~
-!!! error TS2339: Property 'bar2' does not exist on type 'E1'.
-    }
-    
-    var obj10: any;
-    if (obj10 instanceof E) { // can't type narrowing from any.
-        obj10.foo;
-        obj10.bar1;
-        obj10.bar2;
-    }
-    
-    // a construct signature that returns any
-    interface FConstructor {
-        new (): any;
-    }
-    interface F {
-        foo: string;
-        bar: number;
-    }
-    declare var F: FConstructor;
-    
-    var obj11: F | string;
-    if (obj11 instanceof F) { // can't type narrowing, construct signiture returns any.
-        obj11.foo;
-              ~~~
-!!! error TS2339: Property 'foo' does not exist on type 'string | F'.
-        obj11.bar;
-              ~~~
-!!! error TS2339: Property 'bar' does not exist on type 'string | F'.
-    }
-    
-    var obj12: any;
-    if (obj12 instanceof F) { // can't type narrowing from any.
-        obj12.foo;
-        obj12.bar;
-    }
-    
-    // a type with a prototype, it overrides the construct signiture
-    interface GConstructor {
-        prototype: G1; // high priority
-        new (): G2;    // low priority
-    }
-    interface G1 {
-        foo1: number;
-    }
-    interface G2 {
-        foo2: boolean;
-    }
-    declare var G: GConstructor;
-    
-    var obj13: G1 | G2;
-    if (obj13 instanceof G) { // narrowed to G1. G1 is return type of prototype property.
-        obj13.foo1;
-        obj13.foo2;
-              ~~~~
-!!! error TS2339: Property 'foo2' does not exist on type 'G1'.
-    }
-    
-    var obj14: any;
-    if (obj14 instanceof G) { // can't type narrowing from any.
-        obj14.foo1;
-        obj14.foo2;
-    }
-    
-    // a type with a prototype that has any type
-    interface HConstructor {
-        prototype: any; // high priority, but any type is ignored. interface has implicit `prototype: any`.
-        new (): H;      // low priority
-    }
-    interface H {
-        foo: number;
-    }
-    declare var H: HConstructor;
-    
-    var obj15: H | string;
-    if (obj15 instanceof H) { // narrowed to H.
-        obj15.foo;
-        obj15.bar;
-              ~~~
-!!! error TS2339: Property 'bar' does not exist on type 'H'.
-    }
-    
-    var obj16: any;
-    if (obj16 instanceof H) { // can't type narrowing from any.
-        obj16.foo1;
-        obj16.foo2;
-    }
+tests/cases/conformance/expressions/typeGuards/typeGuardsWithInstanceOfByConstructorSignature.ts(12,10): error TS2339: Property 'bar' does not exist on type 'A'.
+tests/cases/conformance/expressions/typeGuards/typeGuardsWithInstanceOfByConstructorSignature.ts(33,5): error TS2322: Type 'string' is not assignable to type 'number'.
+tests/cases/conformance/expressions/typeGuards/typeGuardsWithInstanceOfByConstructorSignature.ts(34,10): error TS2339: Property 'bar' does not exist on type 'B<number>'.
+tests/cases/conformance/expressions/typeGuards/typeGuardsWithInstanceOfByConstructorSignature.ts(63,10): error TS2339: Property 'bar2' does not exist on type 'C1'.
+tests/cases/conformance/expressions/typeGuards/typeGuardsWithInstanceOfByConstructorSignature.ts(82,10): error TS2339: Property 'bar' does not exist on type 'D'.
+tests/cases/conformance/expressions/typeGuards/typeGuardsWithInstanceOfByConstructorSignature.ts(109,10): error TS2339: Property 'bar2' does not exist on type 'E1'.
+tests/cases/conformance/expressions/typeGuards/typeGuardsWithInstanceOfByConstructorSignature.ts(131,11): error TS2339: Property 'foo' does not exist on type 'string | F'.
+tests/cases/conformance/expressions/typeGuards/typeGuardsWithInstanceOfByConstructorSignature.ts(132,11): error TS2339: Property 'bar' does not exist on type 'string | F'.
+tests/cases/conformance/expressions/typeGuards/typeGuardsWithInstanceOfByConstructorSignature.ts(157,11): error TS2339: Property 'foo2' does not exist on type 'G1'.
+tests/cases/conformance/expressions/typeGuards/typeGuardsWithInstanceOfByConstructorSignature.ts(179,11): error TS2339: Property 'bar' does not exist on type 'H'.
+
+
+==== tests/cases/conformance/expressions/typeGuards/typeGuardsWithInstanceOfByConstructorSignature.ts (10 errors) ====
+    interface AConstructor {
+        new (): A;
+    }
+    interface A {
+        foo: string;
+    }
+    declare var A: AConstructor;
+    
+    var obj1: A | string;
+    if (obj1 instanceof A) { // narrowed to A.
+        obj1.foo;
+        obj1.bar;
+             ~~~
+!!! error TS2339: Property 'bar' does not exist on type 'A'.
+    }
+    
+    var obj2: any;
+    if (obj2 instanceof A) { // can't narrow type from 'any'
+        obj2.foo;
+        obj2.bar;
+    }
+    
+    // a construct signature with generics
+    interface BConstructor {
+        new <T>(): B<T>;
+    }
+    interface B<T> {
+        foo: T;
+    }
+    declare var B: BConstructor;
+    
+    var obj3: B<number> | string;
+    if (obj3 instanceof B) { // narrowed to B<number>.
+        obj3.foo = 1;
+        obj3.foo = "str";
+        ~~~~~~~~
+!!! error TS2322: Type 'string' is not assignable to type 'number'.
+        obj3.bar = "str";
+             ~~~
+!!! error TS2339: Property 'bar' does not exist on type 'B<number>'.
+    }
+    
+    var obj4: any;
+    if (obj4 instanceof B) { // can't narrow type from 'any'
+        obj4.foo = "str";
+        obj4.foo = 1;
+        obj4.bar = "str";
+    }
+    
+    // has multiple construct signature
+    interface CConstructor {
+        new (value: string): C1;
+        new (value: number): C2;
+    }
+    interface C1 {
+        foo: string;
+        bar1: number;
+    }
+    interface C2 {
+        foo: string;
+        bar2: number;
+    }
+    declare var C: CConstructor;
+    
+    var obj5: C1 | A;
+    if (obj5 instanceof C) { // narrowed to C1.
+        obj5.foo;
+        obj5.bar1;
+        obj5.bar2;
+             ~~~~
+!!! error TS2339: Property 'bar2' does not exist on type 'C1'.
+    }
+    
+    var obj6: any;
+    if (obj6 instanceof C) { // can't narrow type from 'any'
+        obj6.foo;
+        obj6.bar1;
+        obj6.bar2;
+    }
+    
+    // with object type literal
+    interface D {
+        foo: string;
+    }
+    declare var D: { new (): D; };
+    
+    var obj7: D | string;
+    if (obj7 instanceof D) { // narrowed to D.
+        obj7.foo;
+        obj7.bar;
+             ~~~
+!!! error TS2339: Property 'bar' does not exist on type 'D'.
+    }
+    
+    var obj8: any;
+    if (obj8 instanceof D) { // can't narrow type from 'any'
+        obj8.foo;
+        obj8.bar;
+    }
+    
+    // a construct signature that returns a union type
+    interface EConstructor {
+        new (): E1 | E2;
+    }
+    interface E1 {
+        foo: string;
+        bar1: number;
+    }
+    interface E2 {
+        foo: string;
+        bar2: number;
+    }
+    declare var E: EConstructor;
+    
+    var obj9: E1 | A;
+    if (obj9 instanceof E) { // narrowed to E1.
+        obj9.foo;
+        obj9.bar1;
+        obj9.bar2;
+             ~~~~
+!!! error TS2339: Property 'bar2' does not exist on type 'E1'.
+    }
+    
+    var obj10: any;
+    if (obj10 instanceof E) { // can't narrow type from 'any'
+        obj10.foo;
+        obj10.bar1;
+        obj10.bar2;
+    }
+    
+    // a construct signature that returns any
+    interface FConstructor {
+        new (): any;
+    }
+    interface F {
+        foo: string;
+        bar: number;
+    }
+    declare var F: FConstructor;
+    
+    var obj11: F | string;
+    if (obj11 instanceof F) { // can't type narrowing, construct signature returns any.
+        obj11.foo;
+              ~~~
+!!! error TS2339: Property 'foo' does not exist on type 'string | F'.
+        obj11.bar;
+              ~~~
+!!! error TS2339: Property 'bar' does not exist on type 'string | F'.
+    }
+    
+    var obj12: any;
+    if (obj12 instanceof F) { // can't narrow type from 'any'
+        obj12.foo;
+        obj12.bar;
+    }
+    
+    // a type with a prototype, it overrides the construct signature
+    interface GConstructor {
+        prototype: G1; // high priority
+        new (): G2;    // low priority
+    }
+    interface G1 {
+        foo1: number;
+    }
+    interface G2 {
+        foo2: boolean;
+    }
+    declare var G: GConstructor;
+    
+    var obj13: G1 | G2;
+    if (obj13 instanceof G) { // narrowed to G1. G1 is return type of prototype property.
+        obj13.foo1;
+        obj13.foo2;
+              ~~~~
+!!! error TS2339: Property 'foo2' does not exist on type 'G1'.
+    }
+    
+    var obj14: any;
+    if (obj14 instanceof G) { // can't narrow type from 'any'
+        obj14.foo1;
+        obj14.foo2;
+    }
+    
+    // a type with a prototype that has any type
+    interface HConstructor {
+        prototype: any; // high priority, but any type is ignored. interface has implicit `prototype: any`.
+        new (): H;      // low priority
+    }
+    interface H {
+        foo: number;
+    }
+    declare var H: HConstructor;
+    
+    var obj15: H | string;
+    if (obj15 instanceof H) { // narrowed to H.
+        obj15.foo;
+        obj15.bar;
+              ~~~
+!!! error TS2339: Property 'bar' does not exist on type 'H'.
+    }
+    
+    var obj16: any;
+    if (obj16 instanceof H) { // can't narrow type from 'any'
+        obj16.foo1;
+        obj16.foo2;
+    }
     

tests/baselines/reference/typeGuardsWithInstanceOfByConstructorSignature.js

@@ -1,4 +1,4 @@
-//// [typeGuardsWithInstanceOfByConstructorSignature.ts]
+//// [typeGuardsWithInstanceOfByConstructorSignature.ts]
 interface AConstructor {
     new (): A;
 }
@@ -14,7 +14,7 @@ if (obj1 instanceof A) { // narrowed to A.
 }
 
 var obj2: any;
-if (obj2 instanceof A) { // can't type narrowing from any.
+if (obj2 instanceof A) { // can't narrow type from 'any'
     obj2.foo;
     obj2.bar;
 }
@@ -36,7 +36,7 @@ if (obj3 instanceof B) { // narrowed to B<number>.
 }
 
 var obj4: any;
-if (obj4 instanceof B) { // can't type narrowing from any.
+if (obj4 instanceof B) { // can't narrow type from 'any'
     obj4.foo = "str";
     obj4.foo = 1;
     obj4.bar = "str";
@@ -65,7 +65,7 @@ if (obj5 instanceof C) { // narrowed to C1.
 }
 
 var obj6: any;
-if (obj6 instanceof C) { // can't type narrowing from any.
+if (obj6 instanceof C) { // can't narrow type from 'any'
     obj6.foo;
     obj6.bar1;
     obj6.bar2;
@@ -84,7 +84,7 @@ if (obj7 instanceof D) { // narrowed to D.
 }
 
 var obj8: any;
-if (obj8 instanceof D) { // can't type narrowing from any.
+if (obj8 instanceof D) { // can't narrow type from 'any'
     obj8.foo;
     obj8.bar;
 }
@@ -111,7 +111,7 @@ if (obj9 instanceof E) { // narrowed to E1.
 }
 
 var obj10: any;
-if (obj10 instanceof E) { // can't type narrowing from any.
+if (obj10 instanceof E) { // can't narrow type from 'any'
     obj10.foo;
     obj10.bar1;
     obj10.bar2;
@@ -128,18 +128,18 @@ interface F {
 declare var F: FConstructor;
 
 var obj11: F | string;
-if (obj11 instanceof F) { // can't type narrowing, construct signiture returns any.
+if (obj11 instanceof F) { // can't type narrowing, construct signature returns any.
     obj11.foo;
     obj11.bar;
 }
 
 var obj12: any;
-if (obj12 instanceof F) { // can't type narrowing from any.
+if (obj12 instanceof F) { // can't narrow type from 'any'
     obj12.foo;
     obj12.bar;
 }
 
-// a type with a prototype, it overrides the construct signiture
+// a type with a prototype, it overrides the construct signature
 interface GConstructor {
     prototype: G1; // high priority
     new (): G2;    // low priority
@@ -159,7 +159,7 @@ if (obj13 instanceof G) { // narrowed to G1. G1 is return type of prototype prop
 }
 
 var obj14: any;
-if (obj14 instanceof G) { // can't type narrowing from any.
+if (obj14 instanceof G) { // can't narrow type from 'any'
     obj14.foo1;
     obj14.foo2;
 }
@@ -181,96 +181,96 @@ if (obj15 instanceof H) { // narrowed to H.
 }
 
 var obj16: any;
-if (obj16 instanceof H) { // can't type narrowing from any.
-    obj16.foo1;
-    obj16.foo2;
-}
-
-
-//// [typeGuardsWithInstanceOfByConstructorSignature.js]
-var obj1;
-if (obj1 instanceof A) {
-    obj1.foo;
-    obj1.bar;
-}
-var obj2;
-if (obj2 instanceof A) {
-    obj2.foo;
-    obj2.bar;
-}
-var obj3;
-if (obj3 instanceof B) {
-    obj3.foo = 1;
-    obj3.foo = "str";
-    obj3.bar = "str";
-}
-var obj4;
-if (obj4 instanceof B) {
-    obj4.foo = "str";
-    obj4.foo = 1;
-    obj4.bar = "str";
-}
-var obj5;
-if (obj5 instanceof C) {
-    obj5.foo;
-    obj5.bar1;
-    obj5.bar2;
-}
-var obj6;
-if (obj6 instanceof C) {
-    obj6.foo;
-    obj6.bar1;
-    obj6.bar2;
-}
-var obj7;
-if (obj7 instanceof D) {
-    obj7.foo;
-    obj7.bar;
-}
-var obj8;
-if (obj8 instanceof D) {
-    obj8.foo;
-    obj8.bar;
-}
-var obj9;
-if (obj9 instanceof E) {
-    obj9.foo;
-    obj9.bar1;
-    obj9.bar2;
-}
-var obj10;
-if (obj10 instanceof E) {
-    obj10.foo;
-    obj10.bar1;
-    obj10.bar2;
-}
-var obj11;
-if (obj11 instanceof F) {
-    obj11.foo;
-    obj11.bar;
-}
-var obj12;
-if (obj12 instanceof F) {
-    obj12.foo;
-    obj12.bar;
-}
-var obj13;
-if (obj13 instanceof G) {
-    obj13.foo1;
-    obj13.foo2;
-}
-var obj14;
-if (obj14 instanceof G) {
-    obj14.foo1;
-    obj14.foo2;
-}
-var obj15;
-if (obj15 instanceof H) {
-    obj15.foo;
-    obj15.bar;
-}
-var obj16;
-if (obj16 instanceof H) {
+if (obj16 instanceof H) { // can't narrow type from 'any'
     obj16.foo1;
     obj16.foo2;
 }
+
+
+//// [typeGuardsWithInstanceOfByConstructorSignature.js]
+var obj1;
+if (obj1 instanceof A) {
+    obj1.foo;
+    obj1.bar;
+}
+var obj2;
+if (obj2 instanceof A) {
+    obj2.foo;
+    obj2.bar;
+}
+var obj3;
+if (obj3 instanceof B) {
+    obj3.foo = 1;
+    obj3.foo = "str";
+    obj3.bar = "str";
+}
+var obj4;
+if (obj4 instanceof B) {
+    obj4.foo = "str";
+    obj4.foo = 1;
+    obj4.bar = "str";
+}
+var obj5;
+if (obj5 instanceof C) {
+    obj5.foo;
+    obj5.bar1;
+    obj5.bar2;
+}
+var obj6;
+if (obj6 instanceof C) {
+    obj6.foo;
+    obj6.bar1;
+    obj6.bar2;
+}
+var obj7;
+if (obj7 instanceof D) {
+    obj7.foo;
+    obj7.bar;
+}
+var obj8;
+if (obj8 instanceof D) {
+    obj8.foo;
+    obj8.bar;
+}
+var obj9;
+if (obj9 instanceof E) {
+    obj9.foo;
+    obj9.bar1;
+    obj9.bar2;
+}
+var obj10;
+if (obj10 instanceof E) {
+    obj10.foo;
+    obj10.bar1;
+    obj10.bar2;
+}
+var obj11;
+if (obj11 instanceof F) {
+    obj11.foo;
+    obj11.bar;
+}
+var obj12;
+if (obj12 instanceof F) {
+    obj12.foo;
+    obj12.bar;
+}
+var obj13;
+if (obj13 instanceof G) {
+    obj13.foo1;
+    obj13.foo2;
+}
+var obj14;
+if (obj14 instanceof G) {
+    obj14.foo1;
+    obj14.foo2;
+}
+var obj15;
+if (obj15 instanceof H) {
+    obj15.foo;
+    obj15.bar;
+}
+var obj16;
+if (obj16 instanceof H) {
+    obj16.foo1;
+    obj16.foo2;
+}

tests/cases/conformance/expressions/typeGuards/typeGuardsWithInstanceOfByConstructorSignature.ts

@@ -13,7 +13,7 @@ if (obj1 instanceof A) { // narrowed to A.
 }
 
 var obj2: any;
-if (obj2 instanceof A) { // can't type narrowing from any.
+if (obj2 instanceof A) { // can't narrow type from 'any'
     obj2.foo;
     obj2.bar;
 }
@@ -35,7 +35,7 @@ if (obj3 instanceof B) { // narrowed to B<number>.
 }
 
 var obj4: any;
-if (obj4 instanceof B) { // can't type narrowing from any.
+if (obj4 instanceof B) { // can't narrow type from 'any'
     obj4.foo = "str";
     obj4.foo = 1;
     obj4.bar = "str";
@@ -64,7 +64,7 @@ if (obj5 instanceof C) { // narrowed to C1.
 }
 
 var obj6: any;
-if (obj6 instanceof C) { // can't type narrowing from any.
+if (obj6 instanceof C) { // can't narrow type from 'any'
     obj6.foo;
     obj6.bar1;
     obj6.bar2;
@@ -83,7 +83,7 @@ if (obj7 instanceof D) { // narrowed to D.
 }
 
 var obj8: any;
-if (obj8 instanceof D) { // can't type narrowing from any.
+if (obj8 instanceof D) { // can't narrow type from 'any'
     obj8.foo;
     obj8.bar;
 }
@@ -110,7 +110,7 @@ if (obj9 instanceof E) { // narrowed to E1.
 }
 
 var obj10: any;
-if (obj10 instanceof E) { // can't type narrowing from any.
+if (obj10 instanceof E) { // can't narrow type from 'any'
     obj10.foo;
     obj10.bar1;
     obj10.bar2;
@@ -127,18 +127,18 @@ interface F {
 declare var F: FConstructor;
 
 var obj11: F | string;
-if (obj11 instanceof F) { // can't type narrowing, construct signiture returns any.
+if (obj11 instanceof F) { // can't type narrowing, construct signature returns any.
     obj11.foo;
     obj11.bar;
 }
 
 var obj12: any;
-if (obj12 instanceof F) { // can't type narrowing from any.
+if (obj12 instanceof F) { // can't narrow type from 'any'
     obj12.foo;
     obj12.bar;
 }
 
-// a type with a prototype, it overrides the construct signiture
+// a type with a prototype, it overrides the construct signature
 interface GConstructor {
     prototype: G1; // high priority
     new (): G2;    // low priority
@@ -158,7 +158,7 @@ if (obj13 instanceof G) { // narrowed to G1. G1 is return type of prototype prop
 }
 
 var obj14: any;
-if (obj14 instanceof G) { // can't type narrowing from any.
+if (obj14 instanceof G) { // can't narrow type from 'any'
     obj14.foo1;
     obj14.foo2;
 }
@@ -180,7 +180,7 @@ if (obj15 instanceof H) { // narrowed to H.
 }
 
 var obj16: any;
-if (obj16 instanceof H) { // can't type narrowing from any.
+if (obj16 instanceof H) { // can't narrow type from 'any'
     obj16.foo1;
     obj16.foo2;
 }