Accepted baselines.

tests/baselines/reference/arrayBufferIsViewNarrowsType.types

@@ -4,7 +4,7 @@ var obj: Object;
 >Object : Object
 
 if (ArrayBuffer.isView(obj)) {
->ArrayBuffer.isView(obj) : arg is ArrayBufferView
+>ArrayBuffer.isView(obj) : boolean
 >ArrayBuffer.isView : (arg: any) => arg is ArrayBufferView
 >ArrayBuffer : ArrayBufferConstructor
 >isView : (arg: any) => arg is ArrayBufferView

tests/baselines/reference/declarationEmitIdentifierPredicates01.symbols

@@ -0,0 +1,10 @@
+=== tests/cases/conformance/declarationEmit/typePredicates/declarationEmitIdentifierPredicates01.ts ===
+
+export function f(x: any): x is number {
+>f : Symbol(f, Decl(declarationEmitIdentifierPredicates01.ts, 0, 0))
+>x : Symbol(x, Decl(declarationEmitIdentifierPredicates01.ts, 1, 18))
+>x : Symbol(x, Decl(declarationEmitIdentifierPredicates01.ts, 1, 18))
+
+    return typeof x === "number";
+>x : Symbol(x, Decl(declarationEmitIdentifierPredicates01.ts, 1, 18))
+}

tests/baselines/reference/declarationEmitIdentifierPredicates01.types

@@ -0,0 +1,13 @@
+=== tests/cases/conformance/declarationEmit/typePredicates/declarationEmitIdentifierPredicates01.ts ===
+
+export function f(x: any): x is number {
+>f : (x: any) => x is number
+>x : any
+>x : any
+
+    return typeof x === "number";
+>typeof x === "number" : boolean
+>typeof x : string
+>x : any
+>"number" : string
+}

tests/baselines/reference/declarationEmitIdentifierPredicatesWithPrivateName01.errors.txt

@@ -0,0 +1,14 @@
+tests/cases/conformance/declarationEmit/typePredicates/declarationEmitIdentifierPredicatesWithPrivateName01.ts(6,33): error TS4060: Return type of exported function has or is using private name 'I'.
+
+
+==== tests/cases/conformance/declarationEmit/typePredicates/declarationEmitIdentifierPredicatesWithPrivateName01.ts (1 errors) ====
+    
+    interface I {
+        a: number;
+    }
+    
+    export function f(x: any): x is I {
+                                    ~
+!!! error TS4060: Return type of exported function has or is using private name 'I'.
+        return typeof x.a === "number";
+    }

tests/baselines/reference/declarationEmitThisPredicates01.symbols

@@ -0,0 +1,19 @@
+=== tests/cases/conformance/declarationEmit/typePredicates/declarationEmitThisPredicates01.ts ===
+
+export class C {
+>C : Symbol(C, Decl(declarationEmitThisPredicates01.ts, 0, 0))
+
+    m(): this is D {
+>m : Symbol(m, Decl(declarationEmitThisPredicates01.ts, 1, 16))
+>D : Symbol(D, Decl(declarationEmitThisPredicates01.ts, 5, 1))
+
+        return this instanceof D;
+>this : Symbol(C, Decl(declarationEmitThisPredicates01.ts, 0, 0))
+>D : Symbol(D, Decl(declarationEmitThisPredicates01.ts, 5, 1))
+    }
+}
+
+export class D extends C {
+>D : Symbol(D, Decl(declarationEmitThisPredicates01.ts, 5, 1))
+>C : Symbol(C, Decl(declarationEmitThisPredicates01.ts, 0, 0))
+}

tests/baselines/reference/declarationEmitThisPredicates01.types

@@ -0,0 +1,20 @@
+=== tests/cases/conformance/declarationEmit/typePredicates/declarationEmitThisPredicates01.ts ===
+
+export class C {
+>C : C
+
+    m(): this is D {
+>m : () => this is D
+>D : D
+
+        return this instanceof D;
+>this instanceof D : boolean
+>this : this
+>D : typeof D
+    }
+}
+
+export class D extends C {
+>D : D
+>C : C
+}

tests/baselines/reference/declarationEmitThisPredicates02.errors.txt

@@ -0,0 +1,19 @@
+tests/cases/conformance/declarationEmit/typePredicates/declarationEmitThisPredicates02.ts(9,10): error TS2526: A 'this' type is available only in a non-static member of a class or interface.
+
+
+==== tests/cases/conformance/declarationEmit/typePredicates/declarationEmitThisPredicates02.ts (1 errors) ====
+    
+    export interface Foo {
+        a: string;
+        b: number;
+        c: boolean;
+    }
+    
+    export const obj = {
+        m(): this is Foo {
+             ~~~~
+!!! error TS2526: A 'this' type is available only in a non-static member of a class or interface.
+            let dis = this as Foo;
+            return dis.a != null && dis.b != null && dis.c != null;
+        }
+    }

tests/baselines/reference/declarationEmitThisPredicatesWithPrivateName01.errors.txt

@@ -0,0 +1,15 @@
+tests/cases/conformance/declarationEmit/typePredicates/declarationEmitThisPredicatesWithPrivateName01.ts(3,18): error TS4055: Return type of public method from exported class has or is using private name 'D'.
+
+
+==== tests/cases/conformance/declarationEmit/typePredicates/declarationEmitThisPredicatesWithPrivateName01.ts (1 errors) ====
+    
+    export class C {
+        m(): this is D {
+                     ~
+!!! error TS4055: Return type of public method from exported class has or is using private name 'D'.
+            return this instanceof D;
+        }
+    }
+    
+    class D extends C {
+    }

tests/baselines/reference/declarationEmitThisPredicatesWithPrivateName02.errors.txt

@@ -0,0 +1,22 @@
+tests/cases/conformance/declarationEmit/typePredicates/declarationEmitThisPredicatesWithPrivateName02.ts(8,14): error TS4025: Exported variable 'obj' has or is using private name 'Foo'.
+tests/cases/conformance/declarationEmit/typePredicates/declarationEmitThisPredicatesWithPrivateName02.ts(9,10): error TS2526: A 'this' type is available only in a non-static member of a class or interface.
+
+
+==== tests/cases/conformance/declarationEmit/typePredicates/declarationEmitThisPredicatesWithPrivateName02.ts (2 errors) ====
+    
+    interface Foo {
+        a: string;
+        b: number;
+        c: boolean;
+    }
+    
+    export const obj = {
+                 ~~~
+!!! error TS4025: Exported variable 'obj' has or is using private name 'Foo'.
+        m(): this is Foo {
+             ~~~~
+!!! error TS2526: A 'this' type is available only in a non-static member of a class or interface.
+            let dis = this as Foo;
+            return dis.a != null && dis.b != null && dis.c != null;
+        }
+    }

tests/baselines/reference/isArray.types

@@ -4,7 +4,7 @@ var maybeArray: number | number[];
 
 
 if (Array.isArray(maybeArray)) {
->Array.isArray(maybeArray) : arg is any[]
+>Array.isArray(maybeArray) : boolean
 >Array.isArray : (arg: any) => arg is any[]
 >Array : ArrayConstructor
 >isArray : (arg: any) => arg is any[]

tests/baselines/reference/stringLiteralCheckedInIf02.types

@@ -31,7 +31,7 @@ function f(foo: T) {
 >T : ("a" | "b")[] | "a" | "b"
 
     if (isS(foo)) {
->isS(foo) : t is "a" | "b"
+>isS(foo) : boolean
 >isS : (t: ("a" | "b")[] | "a" | "b") => t is "a" | "b"
 >foo : ("a" | "b")[] | "a" | "b"
 

tests/baselines/reference/stringLiteralTypesAsTags01.types

@@ -88,7 +88,7 @@ let x: A = {
 }
 
 if (hasKind(x, "A")) {
->hasKind(x, "A") : entity is A
+>hasKind(x, "A") : boolean
 >hasKind : { (entity: Entity, kind: "A"): entity is A; (entity: Entity, kind: "B"): entity is B; (entity: Entity, kind: "A" | "B"): entity is Entity; }
 >x : A
 >"A" : "A"
@@ -105,7 +105,7 @@ else {
 
 if (!hasKind(x, "B")) {
 >!hasKind(x, "B") : boolean
->hasKind(x, "B") : entity is B
+>hasKind(x, "B") : boolean
 >hasKind : { (entity: Entity, kind: "A"): entity is A; (entity: Entity, kind: "B"): entity is B; (entity: Entity, kind: "A" | "B"): entity is Entity; }
 >x : A
 >"B" : "B"

tests/baselines/reference/stringLiteralTypesAsTags02.types

@@ -82,7 +82,7 @@ let x: A = {
 }
 
 if (hasKind(x, "A")) {
->hasKind(x, "A") : entity is A
+>hasKind(x, "A") : boolean
 >hasKind : { (entity: Entity, kind: "A"): entity is A; (entity: Entity, kind: "B"): entity is B; }
 >x : A
 >"A" : "A"
@@ -99,7 +99,7 @@ else {
 
 if (!hasKind(x, "B")) {
 >!hasKind(x, "B") : boolean
->hasKind(x, "B") : entity is B
+>hasKind(x, "B") : boolean
 >hasKind : { (entity: Entity, kind: "A"): entity is A; (entity: Entity, kind: "B"): entity is B; }
 >x : A
 >"B" : "B"

tests/baselines/reference/stringLiteralTypesAsTags03.types

@@ -85,7 +85,7 @@ let x: A = {
 }
 
 if (hasKind(x, "A")) {
->hasKind(x, "A") : entity is A
+>hasKind(x, "A") : boolean
 >hasKind : { (entity: Entity, kind: "A"): entity is A; (entity: Entity, kind: "B"): entity is B; }
 >x : A
 >"A" : "A"
@@ -102,7 +102,7 @@ else {
 
 if (!hasKind(x, "B")) {
 >!hasKind(x, "B") : boolean
->hasKind(x, "B") : entity is B
+>hasKind(x, "B") : boolean
 >hasKind : { (entity: Entity, kind: "A"): entity is A; (entity: Entity, kind: "B"): entity is B; }
 >x : A
 >"B" : "B"

tests/baselines/reference/stringLiteralTypesTypePredicates01.types

@@ -36,7 +36,7 @@ var x: Kind = "A";
 >"A" : "A"
 
 if (kindIs(x, "A")) {
->kindIs(x, "A") : kind is "A"
+>kindIs(x, "A") : boolean
 >kindIs : { (kind: "A" | "B", is: "A"): kind is "A"; (kind: "A" | "B", is: "B"): kind is "B"; }
 >x : "A" | "B"
 >"A" : "A"
@@ -53,7 +53,7 @@ else {
 
 if (!kindIs(x, "B")) {
 >!kindIs(x, "B") : boolean
->kindIs(x, "B") : kind is "B"
+>kindIs(x, "B") : boolean
 >kindIs : { (kind: "A" | "B", is: "A"): kind is "A"; (kind: "A" | "B", is: "B"): kind is "B"; }
 >x : "A" | "B"
 >"B" : "B"

tests/baselines/reference/typeGuardFunction.types

@@ -54,7 +54,7 @@ var b: B;
 
 // Basic
 if (isC(a)) {
->isC(a) : p1 is C
+>isC(a) : boolean
 >isC : (p1: any) => p1 is C
 >a : A
 
@@ -70,7 +70,7 @@ var subType: C;
 >C : C
 
 if(isA(subType)) {
->isA(subType) : p1 is A
+>isA(subType) : boolean
 >isA : (p1: any) => p1 is A
 >subType : C
 
@@ -87,7 +87,7 @@ var union: A | B;
 >B : B
 
 if(isA(union)) {
->isA(union) : p1 is A
+>isA(union) : boolean
 >isA : (p1: any) => p1 is A
 >union : A | B
 
@@ -118,7 +118,7 @@ declare function isC_multipleParams(p1, p2): p1 is C;
 >C : C
 
 if (isC_multipleParams(a, 0)) {
->isC_multipleParams(a, 0) : p1 is C
+>isC_multipleParams(a, 0) : boolean
 >isC_multipleParams : (p1: any, p2: any) => p1 is C
 >a : A
 >0 : number
@@ -197,7 +197,7 @@ declare function acceptingBoolean(a: boolean);
 acceptingBoolean(isA(a));
 >acceptingBoolean(isA(a)) : any
 >acceptingBoolean : (a: boolean) => any
->isA(a) : p1 is A
+>isA(a) : boolean
 >isA : (p1: any) => p1 is A
 >a : A
 
@@ -223,8 +223,8 @@ let union2: C | B;
 let union3: boolean | B = isA(union2) || union2;
 >union3 : boolean | B
 >B : B
->isA(union2) || union2 : p1 is A | B
->isA(union2) : p1 is A
+>isA(union2) || union2 : boolean | B
+>isA(union2) : boolean
 >isA : (p1: any) => p1 is A
 >union2 : C | B
 >union2 : B

tests/baselines/reference/typeGuardFunctionErrors.errors.txt

@@ -1,5 +1,5 @@
 tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(2,7): error TS2300: Duplicate identifier 'A'.
-tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(15,12): error TS2322: Type 'string' is not assignable to type 'x is A'.
+tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(15,12): error TS2322: Type 'string' is not assignable to type 'boolean'.
 tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(18,55): error TS2304: Cannot find name 'x'.
 tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(18,57): error TS1144: '{' or ';' expected.
 tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(18,57): error TS2304: Cannot find name 'is'.
@@ -43,9 +43,13 @@ tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(98,22)
 tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(98,22): error TS2304: Cannot find name 'is'.
 tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(98,25): error TS1005: ';' expected.
 tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(98,27): error TS1005: ';' expected.
+tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(104,25): error TS1228: A type predicate is only allowed in return type position for functions and methods.
 tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(105,16): error TS2322: Type 'boolean' is not assignable to type 'D'.
 tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(105,16): error TS2409: Return type of constructor signature must be assignable to the instance type of the class
+tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(107,20): error TS1228: A type predicate is only allowed in return type position for functions and methods.
+tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(110,20): error TS1228: A type predicate is only allowed in return type position for functions and methods.
 tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(111,16): error TS2408: Setters cannot return a value.
+tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(116,18): error TS1228: A type predicate is only allowed in return type position for functions and methods.
 tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(120,22): error TS2304: Cannot find name 'p1'.
 tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(120,25): error TS1005: ';' expected.
 tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(120,25): error TS2304: Cannot find name 'is'.
@@ -57,7 +61,7 @@ tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(133,34
 tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(137,39): error TS1230: A type predicate cannot reference element 'p1' in a binding pattern.
 
 
-==== tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts (50 errors) ====
+==== tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts (54 errors) ====
     
     class A {
           ~
@@ -76,7 +80,7 @@ tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(137,39
     function hasANonBooleanReturnStatement(x): x is A {
         return '';
                ~~
-!!! error TS2322: Type 'string' is not assignable to type 'x is A'.
+!!! error TS2322: Type 'string' is not assignable to type 'boolean'.
     }
     
     function hasTypeGuardTypeInsideTypeGuardType(x): x is x is A {
@@ -245,6 +249,8 @@ tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(137,39
     // Non-compatiable type predicate positions for signature declarations
     class D {
         constructor(p1: A): p1 is C {
+                            ~~~~~~~
+!!! error TS1228: A type predicate is only allowed in return type position for functions and methods.
             return true;
                    ~~~~
 !!! error TS2322: Type 'boolean' is not assignable to type 'D'.
@@ -252,9 +258,13 @@ tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(137,39
 !!! error TS2409: Return type of constructor signature must be assignable to the instance type of the class
         }
         get m1(p1: A): p1 is C {
+                       ~~~~~~~
+!!! error TS1228: A type predicate is only allowed in return type position for functions and methods.
             return true;
         }
         set m2(p1: A): p1 is C {
+                       ~~~~~~~
+!!! error TS1228: A type predicate is only allowed in return type position for functions and methods.
             return true;
                    ~~~~
 !!! error TS2408: Setters cannot return a value.
@@ -263,6 +273,8 @@ tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(137,39
     
     interface I1 {
         new (p1: A): p1 is C;
+                     ~~~~~~~
+!!! error TS1228: A type predicate is only allowed in return type position for functions and methods.
     }
     
     interface I2 {

tests/baselines/reference/typeGuardFunctionGenerics.types

@@ -100,7 +100,7 @@ let test1: boolean = funA(isB);
 >isB : (p1: any) => p1 is B
 
 if (funB(retC, a)) {
->funB(retC, a) : p2 is C
+>funB(retC, a) : boolean
 >funB : <T>(p1: (p1: any) => T, p2: any) => p2 is T
 >retC : (x: any) => C
 >a : A
@@ -118,7 +118,7 @@ let test2: B = funC(isB);
 >isB : (p1: any) => p1 is B
 
 if (funD(isC, a)) {
->funD(isC, a) : p2 is C
+>funD(isC, a) : boolean
 >funD : <T>(p1: (p1: any) => p1 is T, p2: any) => p2 is T
 >isC : (p1: any) => p1 is C
 >a : A

tests/baselines/reference/typeGuardFunctionOfFormThis.types

@@ -45,7 +45,7 @@ let a: RoyalGuard = new FollowerGuard();
 >FollowerGuard : typeof FollowerGuard
 
 if (a.isLeader()) {
->a.isLeader() : this is LeadGuard
+>a.isLeader() : boolean
 >a.isLeader : () => this is LeadGuard
 >a : RoyalGuard
 >isLeader : () => this is LeadGuard
@@ -57,7 +57,7 @@ if (a.isLeader()) {
 >lead : () => void
 }
 else if (a.isFollower()) {
->a.isFollower() : this is FollowerGuard
+>a.isFollower() : boolean
 >a.isFollower : () => this is FollowerGuard
 >a : RoyalGuard
 >isFollower : () => this is FollowerGuard
@@ -78,7 +78,7 @@ let b: GuardInterface;
 >GuardInterface : GuardInterface
 
 if (b.isLeader()) {
->b.isLeader() : this is LeadGuard
+>b.isLeader() : boolean
 >b.isLeader : () => this is LeadGuard
 >b : GuardInterface
 >isLeader : () => this is LeadGuard
@@ -90,7 +90,7 @@ if (b.isLeader()) {
 >lead : () => void
 }
 else if (b.isFollower()) {
->b.isFollower() : this is FollowerGuard
+>b.isFollower() : boolean
 >b.isFollower : () => this is FollowerGuard
 >b : GuardInterface
 >isFollower : () => this is FollowerGuard
@@ -103,8 +103,8 @@ else if (b.isFollower()) {
 }
 
 if (((a.isLeader)())) {
->((a.isLeader)()) : this is LeadGuard
->(a.isLeader)() : this is LeadGuard
+>((a.isLeader)()) : boolean
+>(a.isLeader)() : boolean
 >(a.isLeader) : () => this is LeadGuard
 >a.isLeader : () => this is LeadGuard
 >a : RoyalGuard
@@ -117,8 +117,8 @@ if (((a.isLeader)())) {
 >lead : () => void
 }
 else if (((a).isFollower())) {
->((a).isFollower()) : this is FollowerGuard
->(a).isFollower() : this is FollowerGuard
+>((a).isFollower()) : boolean
+>(a).isFollower() : boolean
 >(a).isFollower : () => this is FollowerGuard
 >(a) : RoyalGuard
 >a : RoyalGuard
@@ -132,8 +132,8 @@ else if (((a).isFollower())) {
 }
 
 if (((a["isLeader"])())) {
->((a["isLeader"])()) : this is LeadGuard
->(a["isLeader"])() : this is LeadGuard
+>((a["isLeader"])()) : boolean
+>(a["isLeader"])() : boolean
 >(a["isLeader"]) : () => this is LeadGuard
 >a["isLeader"] : () => this is LeadGuard
 >a : RoyalGuard
@@ -146,8 +146,8 @@ if (((a["isLeader"])())) {
 >lead : () => void
 }
 else if (((a)["isFollower"]())) {
->((a)["isFollower"]()) : this is FollowerGuard
->(a)["isFollower"]() : this is FollowerGuard
+>((a)["isFollower"]()) : boolean
+>(a)["isFollower"]() : boolean
 >(a)["isFollower"] : () => this is FollowerGuard
 >(a) : RoyalGuard
 >a : RoyalGuard
@@ -166,7 +166,7 @@ var holder2 = {a};
 >a : RoyalGuard
 
 if (holder2.a.isLeader()) {
->holder2.a.isLeader() : this is LeadGuard
+>holder2.a.isLeader() : boolean
 >holder2.a.isLeader : () => this is LeadGuard
 >holder2.a : RoyalGuard
 >holder2 : { a: RoyalGuard; }
@@ -232,7 +232,7 @@ let guard = new ArrowGuard();
 >ArrowGuard : typeof ArrowGuard
 
 if (guard.isElite()) {
->guard.isElite() : this is ArrowElite
+>guard.isElite() : boolean
 >guard.isElite : () => this is ArrowElite
 >guard : ArrowGuard
 >isElite : () => this is ArrowElite
@@ -244,7 +244,7 @@ if (guard.isElite()) {
 >defend : () => void
 }
 else if (guard.isMedic()) {
->guard.isMedic() : this is ArrowMedic
+>guard.isMedic() : boolean
 >guard.isMedic : () => this is ArrowMedic
 >guard : ArrowGuard
 >isMedic : () => this is ArrowMedic
@@ -297,7 +297,7 @@ let crate: Crate<{}>;
 >Crate : Crate<T>
 
 if (crate.isSundries()) {
->crate.isSundries() : this is Crate<Sundries>
+>crate.isSundries() : boolean
 >crate.isSundries : () => this is Crate<Sundries>
 >crate : Crate<{}>
 >isSundries : () => this is Crate<Sundries>
@@ -312,7 +312,7 @@ if (crate.isSundries()) {
 >true : boolean
 }
 else if (crate.isSupplies()) {
->crate.isSupplies() : this is Crate<Supplies>
+>crate.isSupplies() : boolean
 >crate.isSupplies : () => this is Crate<Supplies>
 >crate : Crate<{}>
 >isSupplies : () => this is Crate<Supplies>
@@ -405,7 +405,7 @@ a.isFollower = mimic.isFollower;
 >isFollower : () => this is MimicFollower
 
 if (mimic.isFollower()) {
->mimic.isFollower() : this is MimicFollower
+>mimic.isFollower() : boolean
 >mimic.isFollower : () => this is MimicFollower
 >mimic : MimicGuard
 >isFollower : () => this is MimicFollower

tests/baselines/reference/typeGuardOfFormFunctionEquality.symbols

@@ -0,0 +1,41 @@
+=== tests/cases/conformance/expressions/typeGuards/typeGuardOfFormFunctionEquality.ts ===
+declare function isString1(a: number, b: Object): b is string;
+>isString1 : Symbol(isString1, Decl(typeGuardOfFormFunctionEquality.ts, 0, 0))
+>a : Symbol(a, Decl(typeGuardOfFormFunctionEquality.ts, 0, 27))
+>b : Symbol(b, Decl(typeGuardOfFormFunctionEquality.ts, 0, 37))
+>Object : Symbol(Object, Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --))
+>b : Symbol(b, Decl(typeGuardOfFormFunctionEquality.ts, 0, 37))
+
+declare function isString2(a: Object): a is string;
+>isString2 : Symbol(isString2, Decl(typeGuardOfFormFunctionEquality.ts, 0, 62))
+>a : Symbol(a, Decl(typeGuardOfFormFunctionEquality.ts, 2, 27))
+>Object : Symbol(Object, Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --))
+>a : Symbol(a, Decl(typeGuardOfFormFunctionEquality.ts, 2, 27))
+
+switch (isString1(0, "")) {
+>isString1 : Symbol(isString1, Decl(typeGuardOfFormFunctionEquality.ts, 0, 0))
+
+    case isString2(""):
+>isString2 : Symbol(isString2, Decl(typeGuardOfFormFunctionEquality.ts, 0, 62))
+
+    default:
+}
+
+var x = isString1(0, "") === isString2("");
+>x : Symbol(x, Decl(typeGuardOfFormFunctionEquality.ts, 9, 3))
+>isString1 : Symbol(isString1, Decl(typeGuardOfFormFunctionEquality.ts, 0, 0))
+>isString2 : Symbol(isString2, Decl(typeGuardOfFormFunctionEquality.ts, 0, 62))
+
+function isString3(a: number, b: number, c: Object): c is string {
+>isString3 : Symbol(isString3, Decl(typeGuardOfFormFunctionEquality.ts, 9, 43))
+>a : Symbol(a, Decl(typeGuardOfFormFunctionEquality.ts, 11, 19))
+>b : Symbol(b, Decl(typeGuardOfFormFunctionEquality.ts, 11, 29))
+>c : Symbol(c, Decl(typeGuardOfFormFunctionEquality.ts, 11, 40))
+>Object : Symbol(Object, Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --))
+>c : Symbol(c, Decl(typeGuardOfFormFunctionEquality.ts, 11, 40))
+
+    return isString1(0, c);
+>isString1 : Symbol(isString1, Decl(typeGuardOfFormFunctionEquality.ts, 0, 0))
+>c : Symbol(c, Decl(typeGuardOfFormFunctionEquality.ts, 11, 40))
+}
+

tests/baselines/reference/typeGuardOfFormFunctionEquality.types

@@ -0,0 +1,54 @@
+=== tests/cases/conformance/expressions/typeGuards/typeGuardOfFormFunctionEquality.ts ===
+declare function isString1(a: number, b: Object): b is string;
+>isString1 : (a: number, b: Object) => b is string
+>a : number
+>b : Object
+>Object : Object
+>b : any
+
+declare function isString2(a: Object): a is string;
+>isString2 : (a: Object) => a is string
+>a : Object
+>Object : Object
+>a : any
+
+switch (isString1(0, "")) {
+>isString1(0, "") : boolean
+>isString1 : (a: number, b: Object) => b is string
+>0 : number
+>"" : string
+
+    case isString2(""):
+>isString2("") : boolean
+>isString2 : (a: Object) => a is string
+>"" : string
+
+    default:
+}
+
+var x = isString1(0, "") === isString2("");
+>x : boolean
+>isString1(0, "") === isString2("") : boolean
+>isString1(0, "") : boolean
+>isString1 : (a: number, b: Object) => b is string
+>0 : number
+>"" : string
+>isString2("") : boolean
+>isString2 : (a: Object) => a is string
+>"" : string
+
+function isString3(a: number, b: number, c: Object): c is string {
+>isString3 : (a: number, b: number, c: Object) => c is string
+>a : number
+>b : number
+>c : Object
+>Object : Object
+>c : any
+
+    return isString1(0, c);
+>isString1(0, c) : boolean
+>isString1 : (a: number, b: Object) => b is string
+>0 : number
+>c : Object
+}
+

tests/baselines/reference/typeGuardOfFormIsType.types

@@ -67,7 +67,7 @@ str = isC1(c1Orc2) && c1Orc2.p1; // C1
 >str = isC1(c1Orc2) && c1Orc2.p1 : string
 >str : string
 >isC1(c1Orc2) && c1Orc2.p1 : string
->isC1(c1Orc2) : x is C1
+>isC1(c1Orc2) : boolean
 >isC1 : (x: any) => x is C1
 >c1Orc2 : C1 | C2
 >c1Orc2.p1 : string
@@ -78,7 +78,7 @@ num = isC2(c1Orc2) && c1Orc2.p2; // C2
 >num = isC2(c1Orc2) && c1Orc2.p2 : number
 >num : number
 >isC2(c1Orc2) && c1Orc2.p2 : number
->isC2(c1Orc2) : x is C2
+>isC2(c1Orc2) : boolean
 >isC2 : (x: any) => x is C2
 >c1Orc2 : C1 | C2
 >c1Orc2.p2 : number
@@ -89,7 +89,7 @@ str = isD1(c1Orc2) && c1Orc2.p1; // D1
 >str = isD1(c1Orc2) && c1Orc2.p1 : string
 >str : string
 >isD1(c1Orc2) && c1Orc2.p1 : string
->isD1(c1Orc2) : x is D1
+>isD1(c1Orc2) : boolean
 >isD1 : (x: any) => x is D1
 >c1Orc2 : C1 | C2
 >c1Orc2.p1 : string
@@ -100,7 +100,7 @@ num = isD1(c1Orc2) && c1Orc2.p3; // D1
 >num = isD1(c1Orc2) && c1Orc2.p3 : number
 >num : number
 >isD1(c1Orc2) && c1Orc2.p3 : number
->isD1(c1Orc2) : x is D1
+>isD1(c1Orc2) : boolean
 >isD1 : (x: any) => x is D1
 >c1Orc2 : C1 | C2
 >c1Orc2.p3 : number
@@ -116,7 +116,7 @@ num = isC2(c2Ord1) && c2Ord1.p2; // C2
 >num = isC2(c2Ord1) && c2Ord1.p2 : number
 >num : number
 >isC2(c2Ord1) && c2Ord1.p2 : number
->isC2(c2Ord1) : x is C2
+>isC2(c2Ord1) : boolean
 >isC2 : (x: any) => x is C2
 >c2Ord1 : C2 | D1
 >c2Ord1.p2 : number
@@ -127,7 +127,7 @@ num = isD1(c2Ord1) && c2Ord1.p3; // D1
 >num = isD1(c2Ord1) && c2Ord1.p3 : number
 >num : number
 >isD1(c2Ord1) && c2Ord1.p3 : number
->isD1(c2Ord1) : x is D1
+>isD1(c2Ord1) : boolean
 >isD1 : (x: any) => x is D1
 >c2Ord1 : C2 | D1
 >c2Ord1.p3 : number
@@ -138,7 +138,7 @@ str = isD1(c2Ord1) && c2Ord1.p1; // D1
 >str = isD1(c2Ord1) && c2Ord1.p1 : string
 >str : string
 >isD1(c2Ord1) && c2Ord1.p1 : string
->isD1(c2Ord1) : x is D1
+>isD1(c2Ord1) : boolean
 >isD1 : (x: any) => x is D1
 >c2Ord1 : C2 | D1
 >c2Ord1.p1 : string
@@ -150,7 +150,7 @@ var r2: C2 | D1 = isC1(c2Ord1) && c2Ord1; // C2 | D1
 >C2 : C2
 >D1 : D1
 >isC1(c2Ord1) && c2Ord1 : D1
->isC1(c2Ord1) : x is C1
+>isC1(c2Ord1) : boolean
 >isC1 : (x: any) => x is C1
 >c2Ord1 : C2 | D1
 >c2Ord1 : D1

tests/baselines/reference/typeGuardOfFormIsTypeOnInterfaces.types

@@ -98,7 +98,7 @@ str = isC1(c1Orc2) && c1Orc2.p1; // C1
 >str = isC1(c1Orc2) && c1Orc2.p1 : string
 >str : string
 >isC1(c1Orc2) && c1Orc2.p1 : string
->isC1(c1Orc2) : x is C1
+>isC1(c1Orc2) : boolean
 >isC1 : (x: any) => x is C1
 >c1Orc2 : C1 | C2
 >c1Orc2.p1 : string
@@ -109,7 +109,7 @@ num = isC2(c1Orc2) && c1Orc2.p2; // C2
 >num = isC2(c1Orc2) && c1Orc2.p2 : number
 >num : number
 >isC2(c1Orc2) && c1Orc2.p2 : number
->isC2(c1Orc2) : x is C2
+>isC2(c1Orc2) : boolean
 >isC2 : (x: any) => x is C2
 >c1Orc2 : C1 | C2
 >c1Orc2.p2 : number
@@ -120,7 +120,7 @@ str = isD1(c1Orc2) && c1Orc2.p1; // D1
 >str = isD1(c1Orc2) && c1Orc2.p1 : string
 >str : string
 >isD1(c1Orc2) && c1Orc2.p1 : string
->isD1(c1Orc2) : x is D1
+>isD1(c1Orc2) : boolean
 >isD1 : (x: any) => x is D1
 >c1Orc2 : C1 | C2
 >c1Orc2.p1 : string
@@ -131,7 +131,7 @@ num = isD1(c1Orc2) && c1Orc2.p3; // D1
 >num = isD1(c1Orc2) && c1Orc2.p3 : number
 >num : number
 >isD1(c1Orc2) && c1Orc2.p3 : number
->isD1(c1Orc2) : x is D1
+>isD1(c1Orc2) : boolean
 >isD1 : (x: any) => x is D1
 >c1Orc2 : C1 | C2
 >c1Orc2.p3 : number
@@ -147,7 +147,7 @@ num = isC2(c2Ord1) && c2Ord1.p2; // C2
 >num = isC2(c2Ord1) && c2Ord1.p2 : number
 >num : number
 >isC2(c2Ord1) && c2Ord1.p2 : number
->isC2(c2Ord1) : x is C2
+>isC2(c2Ord1) : boolean
 >isC2 : (x: any) => x is C2
 >c2Ord1 : C2 | D1
 >c2Ord1.p2 : number
@@ -158,7 +158,7 @@ num = isD1(c2Ord1) && c2Ord1.p3; // D1
 >num = isD1(c2Ord1) && c2Ord1.p3 : number
 >num : number
 >isD1(c2Ord1) && c2Ord1.p3 : number
->isD1(c2Ord1) : x is D1
+>isD1(c2Ord1) : boolean
 >isD1 : (x: any) => x is D1
 >c2Ord1 : C2 | D1
 >c2Ord1.p3 : number
@@ -169,7 +169,7 @@ str = isD1(c2Ord1) && c2Ord1.p1; // D1
 >str = isD1(c2Ord1) && c2Ord1.p1 : string
 >str : string
 >isD1(c2Ord1) && c2Ord1.p1 : string
->isD1(c2Ord1) : x is D1
+>isD1(c2Ord1) : boolean
 >isD1 : (x: any) => x is D1
 >c2Ord1 : C2 | D1
 >c2Ord1.p1 : string
@@ -181,7 +181,7 @@ var r2: C2 | D1 = isC1(c2Ord1) && c2Ord1; // C2 | D1
 >C2 : C2
 >D1 : D1
 >isC1(c2Ord1) && c2Ord1 : D1
->isC1(c2Ord1) : x is C1
+>isC1(c2Ord1) : boolean
 >isC1 : (x: any) => x is C1
 >c2Ord1 : C2 | D1
 >c2Ord1 : D1

tests/baselines/reference/typeGuardOfFormThisMember.errors.txt

@@ -0,0 +1,130 @@
+tests/cases/conformance/expressions/typeGuards/typeGuardOfFormThisMember.ts(4,10): error TS1228: A type predicate is only allowed in return type position for functions and methods.
+tests/cases/conformance/expressions/typeGuards/typeGuardOfFormThisMember.ts(5,17): error TS1228: A type predicate is only allowed in return type position for functions and methods.
+tests/cases/conformance/expressions/typeGuards/typeGuardOfFormThisMember.ts(11,22): error TS1228: A type predicate is only allowed in return type position for functions and methods.
+tests/cases/conformance/expressions/typeGuards/typeGuardOfFormThisMember.ts(14,16): error TS1228: A type predicate is only allowed in return type position for functions and methods.
+tests/cases/conformance/expressions/typeGuards/typeGuardOfFormThisMember.ts(34,8): error TS2339: Property 'content' does not exist on type 'FileSystemObject'.
+tests/cases/conformance/expressions/typeGuards/typeGuardOfFormThisMember.ts(36,9): error TS2339: Property 'host' does not exist on type 'FileSystemObject'.
+tests/cases/conformance/expressions/typeGuards/typeGuardOfFormThisMember.ts(37,9): error TS2339: Property 'content' does not exist on type 'FileSystemObject'.
+tests/cases/conformance/expressions/typeGuards/typeGuardOfFormThisMember.ts(41,8): error TS2339: Property 'children' does not exist on type 'FileSystemObject'.
+tests/cases/conformance/expressions/typeGuards/typeGuardOfFormThisMember.ts(44,8): error TS2339: Property 'host' does not exist on type 'FileSystemObject'.
+tests/cases/conformance/expressions/typeGuards/typeGuardOfFormThisMember.ts(57,13): error TS1228: A type predicate is only allowed in return type position for functions and methods.
+tests/cases/conformance/expressions/typeGuards/typeGuardOfFormThisMember.ts(58,15): error TS1228: A type predicate is only allowed in return type position for functions and methods.
+tests/cases/conformance/expressions/typeGuards/typeGuardOfFormThisMember.ts(63,9): error TS2339: Property 'lead' does not exist on type 'GenericGuard<File>'.
+tests/cases/conformance/expressions/typeGuards/typeGuardOfFormThisMember.ts(66,9): error TS2339: Property 'follow' does not exist on type 'GenericGuard<File>'.
+tests/cases/conformance/expressions/typeGuards/typeGuardOfFormThisMember.ts(70,19): error TS1228: A type predicate is only allowed in return type position for functions and methods.
+tests/cases/conformance/expressions/typeGuards/typeGuardOfFormThisMember.ts(79,11): error TS2339: Property 'do' does not exist on type 'SpecificGuard'.
+
+
+==== tests/cases/conformance/expressions/typeGuards/typeGuardOfFormThisMember.ts (15 errors) ====
+    // There's a 'File' class in the stdlib, wrap with a namespace to avoid collision
+    namespace Test {
+    	export class FileSystemObject {
+    		isFSO: this is FileSystemObject;
+    		       ~~~~~~~~~~~~~~~~~~~~~~~~
+!!! error TS1228: A type predicate is only allowed in return type position for functions and methods.
+    		get isFile(): this is File {
+    		              ~~~~~~~~~~~~
+!!! error TS1228: A type predicate is only allowed in return type position for functions and methods.
+    			return this instanceof File;
+    		}
+    		set isFile(param) {
+    			// noop
+    		}
+    		get isDirectory(): this is Directory {
+    		                   ~~~~~~~~~~~~~~~~~
+!!! error TS1228: A type predicate is only allowed in return type position for functions and methods.
+    			return this instanceof Directory;
+    		}
+    		isNetworked: this is (Networked & this);
+    		             ~~~~~~~~~~~~~~~~~~~~~~~~~~
+!!! error TS1228: A type predicate is only allowed in return type position for functions and methods.
+    		constructor(public path: string) {}
+    	}
+    
+    	export class File extends FileSystemObject {
+    		constructor(path: string, public content: string) { super(path); }
+    	}
+    	export class Directory extends FileSystemObject {
+    		children: FileSystemObject[];
+    	}
+    	export interface Networked {
+    		host: string;
+    	}
+    
+    	let file: FileSystemObject = new File("foo/bar.txt", "foo");
+    	file.isNetworked = false;
+    	file.isFSO = file.isFile;
+    	file.isFile = true;
+    	let x = file.isFile;
+    	if (file.isFile) {
+    		file.content;
+    		     ~~~~~~~
+!!! error TS2339: Property 'content' does not exist on type 'FileSystemObject'.
+    		if (file.isNetworked) {
+    			file.host;
+    			     ~~~~
+!!! error TS2339: Property 'host' does not exist on type 'FileSystemObject'.
+    			file.content;
+    			     ~~~~~~~
+!!! error TS2339: Property 'content' does not exist on type 'FileSystemObject'.
+    		}
+    	}
+    	else if (file.isDirectory) {
+    		file.children;
+    		     ~~~~~~~~
+!!! error TS2339: Property 'children' does not exist on type 'FileSystemObject'.
+    	}
+    	else if (file.isNetworked) {
+    		file.host;
+    		     ~~~~
+!!! error TS2339: Property 'host' does not exist on type 'FileSystemObject'.
+    	}
+    	
+    	interface GenericLeadGuard<T> extends GenericGuard<T> {
+    		lead(): void;
+    	}
+    	
+    	interface GenericFollowerGuard<T> extends GenericGuard<T> {
+    		follow(): void;
+    	}
+    	
+    	interface GenericGuard<T> {
+    		target: T;
+    		isLeader: this is (GenericLeadGuard<T>);
+    		          ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+!!! error TS1228: A type predicate is only allowed in return type position for functions and methods.
+    		isFollower: this is GenericFollowerGuard<T>;
+    		            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+!!! error TS1228: A type predicate is only allowed in return type position for functions and methods.
+    	}
+    
+    	let guard: GenericGuard<File>;
+    	if (guard.isLeader) {
+    		guard.lead();
+    		      ~~~~
+!!! error TS2339: Property 'lead' does not exist on type 'GenericGuard<File>'.
+    	}
+    	else if (guard.isFollower) {
+    		guard.follow();
+    		      ~~~~~~
+!!! error TS2339: Property 'follow' does not exist on type 'GenericGuard<File>'.
+    	}
+    
+    	interface SpecificGuard {
+    		isMoreSpecific: this is MoreSpecificGuard;
+    		                ~~~~~~~~~~~~~~~~~~~~~~~~~
+!!! error TS1228: A type predicate is only allowed in return type position for functions and methods.
+    	}
+    
+    	interface MoreSpecificGuard extends SpecificGuard {
+    		do(): void;
+    	}
+    
+    	let general: SpecificGuard;
+    	if (general.isMoreSpecific) {
+    		general.do();
+    		        ~~
+!!! error TS2339: Property 'do' does not exist on type 'SpecificGuard'.
+    	}
+    }
+    

tests/baselines/reference/typeGuardOfFormThisMember.symbols

@@ -1,240 +0,0 @@
-=== tests/cases/conformance/expressions/typeGuards/typeGuardOfFormThisMember.ts ===
-// There's a 'File' class in the stdlib, wrap with a namespace to avoid collision
-namespace Test {
->Test : Symbol(Test, Decl(typeGuardOfFormThisMember.ts, 0, 0))
-
-	export class FileSystemObject {
->FileSystemObject : Symbol(FileSystemObject, Decl(typeGuardOfFormThisMember.ts, 1, 16))
-
-		isFSO: this is FileSystemObject;
->isFSO : Symbol(isFSO, Decl(typeGuardOfFormThisMember.ts, 2, 32))
->FileSystemObject : Symbol(FileSystemObject, Decl(typeGuardOfFormThisMember.ts, 1, 16))
-
-		get isFile(): this is File {
->isFile : Symbol(isFile, Decl(typeGuardOfFormThisMember.ts, 3, 34), Decl(typeGuardOfFormThisMember.ts, 6, 3))
->File : Symbol(File, Decl(typeGuardOfFormThisMember.ts, 15, 2))
-
-			return this instanceof File;
->this : Symbol(FileSystemObject, Decl(typeGuardOfFormThisMember.ts, 1, 16))
->File : Symbol(File, Decl(typeGuardOfFormThisMember.ts, 15, 2))
-		}
-		set isFile(param) {
->isFile : Symbol(isFile, Decl(typeGuardOfFormThisMember.ts, 3, 34), Decl(typeGuardOfFormThisMember.ts, 6, 3))
->param : Symbol(param, Decl(typeGuardOfFormThisMember.ts, 7, 13))
-
-			// noop
-		}
-		get isDirectory(): this is Directory {
->isDirectory : Symbol(isDirectory, Decl(typeGuardOfFormThisMember.ts, 9, 3))
->Directory : Symbol(Directory, Decl(typeGuardOfFormThisMember.ts, 19, 2))
-
-			return this instanceof Directory;
->this : Symbol(FileSystemObject, Decl(typeGuardOfFormThisMember.ts, 1, 16))
->Directory : Symbol(Directory, Decl(typeGuardOfFormThisMember.ts, 19, 2))
-		}
-		isNetworked: this is (Networked & this);
->isNetworked : Symbol(isNetworked, Decl(typeGuardOfFormThisMember.ts, 12, 3))
->Networked : Symbol(Networked, Decl(typeGuardOfFormThisMember.ts, 22, 2))
-
-		constructor(public path: string) {}
->path : Symbol(path, Decl(typeGuardOfFormThisMember.ts, 14, 14))
-	}
-
-	export class File extends FileSystemObject {
->File : Symbol(File, Decl(typeGuardOfFormThisMember.ts, 15, 2))
->FileSystemObject : Symbol(FileSystemObject, Decl(typeGuardOfFormThisMember.ts, 1, 16))
-
-		constructor(path: string, public content: string) { super(path); }
->path : Symbol(path, Decl(typeGuardOfFormThisMember.ts, 18, 14))
->content : Symbol(content, Decl(typeGuardOfFormThisMember.ts, 18, 27))
->super : Symbol(FileSystemObject, Decl(typeGuardOfFormThisMember.ts, 1, 16))
->path : Symbol(path, Decl(typeGuardOfFormThisMember.ts, 18, 14))
-	}
-	export class Directory extends FileSystemObject {
->Directory : Symbol(Directory, Decl(typeGuardOfFormThisMember.ts, 19, 2))
->FileSystemObject : Symbol(FileSystemObject, Decl(typeGuardOfFormThisMember.ts, 1, 16))
-
-		children: FileSystemObject[];
->children : Symbol(children, Decl(typeGuardOfFormThisMember.ts, 20, 50))
->FileSystemObject : Symbol(FileSystemObject, Decl(typeGuardOfFormThisMember.ts, 1, 16))
-	}
-	export interface Networked {
->Networked : Symbol(Networked, Decl(typeGuardOfFormThisMember.ts, 22, 2))
-
-		host: string;
->host : Symbol(host, Decl(typeGuardOfFormThisMember.ts, 23, 29))
-	}
-
-	let file: FileSystemObject = new File("foo/bar.txt", "foo");
->file : Symbol(file, Decl(typeGuardOfFormThisMember.ts, 27, 4))
->FileSystemObject : Symbol(FileSystemObject, Decl(typeGuardOfFormThisMember.ts, 1, 16))
->File : Symbol(File, Decl(typeGuardOfFormThisMember.ts, 15, 2))
-
-	file.isNetworked = false;
->file.isNetworked : Symbol(FileSystemObject.isNetworked, Decl(typeGuardOfFormThisMember.ts, 12, 3))
->file : Symbol(file, Decl(typeGuardOfFormThisMember.ts, 27, 4))
->isNetworked : Symbol(FileSystemObject.isNetworked, Decl(typeGuardOfFormThisMember.ts, 12, 3))
-
-	file.isFSO = file.isFile;
->file.isFSO : Symbol(FileSystemObject.isFSO, Decl(typeGuardOfFormThisMember.ts, 2, 32))
->file : Symbol(file, Decl(typeGuardOfFormThisMember.ts, 27, 4))
->isFSO : Symbol(FileSystemObject.isFSO, Decl(typeGuardOfFormThisMember.ts, 2, 32))
->file.isFile : Symbol(FileSystemObject.isFile, Decl(typeGuardOfFormThisMember.ts, 3, 34), Decl(typeGuardOfFormThisMember.ts, 6, 3))
->file : Symbol(file, Decl(typeGuardOfFormThisMember.ts, 27, 4))
->isFile : Symbol(FileSystemObject.isFile, Decl(typeGuardOfFormThisMember.ts, 3, 34), Decl(typeGuardOfFormThisMember.ts, 6, 3))
-
-	file.isFile = true;
->file.isFile : Symbol(FileSystemObject.isFile, Decl(typeGuardOfFormThisMember.ts, 3, 34), Decl(typeGuardOfFormThisMember.ts, 6, 3))
->file : Symbol(file, Decl(typeGuardOfFormThisMember.ts, 27, 4))
->isFile : Symbol(FileSystemObject.isFile, Decl(typeGuardOfFormThisMember.ts, 3, 34), Decl(typeGuardOfFormThisMember.ts, 6, 3))
-
-	let x = file.isFile;
->x : Symbol(x, Decl(typeGuardOfFormThisMember.ts, 31, 4))
->file.isFile : Symbol(FileSystemObject.isFile, Decl(typeGuardOfFormThisMember.ts, 3, 34), Decl(typeGuardOfFormThisMember.ts, 6, 3))
->file : Symbol(file, Decl(typeGuardOfFormThisMember.ts, 27, 4))
->isFile : Symbol(FileSystemObject.isFile, Decl(typeGuardOfFormThisMember.ts, 3, 34), Decl(typeGuardOfFormThisMember.ts, 6, 3))
-
-	if (file.isFile) {
->file.isFile : Symbol(FileSystemObject.isFile, Decl(typeGuardOfFormThisMember.ts, 3, 34), Decl(typeGuardOfFormThisMember.ts, 6, 3))
->file : Symbol(file, Decl(typeGuardOfFormThisMember.ts, 27, 4))
->isFile : Symbol(FileSystemObject.isFile, Decl(typeGuardOfFormThisMember.ts, 3, 34), Decl(typeGuardOfFormThisMember.ts, 6, 3))
-
-		file.content;
->file.content : Symbol(File.content, Decl(typeGuardOfFormThisMember.ts, 18, 27))
->file : Symbol(file, Decl(typeGuardOfFormThisMember.ts, 27, 4))
->content : Symbol(File.content, Decl(typeGuardOfFormThisMember.ts, 18, 27))
-
-		if (file.isNetworked) {
->file.isNetworked : Symbol(FileSystemObject.isNetworked, Decl(typeGuardOfFormThisMember.ts, 12, 3))
->file : Symbol(file, Decl(typeGuardOfFormThisMember.ts, 27, 4))
->isNetworked : Symbol(FileSystemObject.isNetworked, Decl(typeGuardOfFormThisMember.ts, 12, 3))
-
-			file.host;
->file.host : Symbol(Networked.host, Decl(typeGuardOfFormThisMember.ts, 23, 29))
->file : Symbol(file, Decl(typeGuardOfFormThisMember.ts, 27, 4))
->host : Symbol(Networked.host, Decl(typeGuardOfFormThisMember.ts, 23, 29))
-
-			file.content;
->file.content : Symbol(File.content, Decl(typeGuardOfFormThisMember.ts, 18, 27))
->file : Symbol(file, Decl(typeGuardOfFormThisMember.ts, 27, 4))
->content : Symbol(File.content, Decl(typeGuardOfFormThisMember.ts, 18, 27))
-		}
-	}
-	else if (file.isDirectory) {
->file.isDirectory : Symbol(FileSystemObject.isDirectory, Decl(typeGuardOfFormThisMember.ts, 9, 3))
->file : Symbol(file, Decl(typeGuardOfFormThisMember.ts, 27, 4))
->isDirectory : Symbol(FileSystemObject.isDirectory, Decl(typeGuardOfFormThisMember.ts, 9, 3))
-
-		file.children;
->file.children : Symbol(Directory.children, Decl(typeGuardOfFormThisMember.ts, 20, 50))
->file : Symbol(file, Decl(typeGuardOfFormThisMember.ts, 27, 4))
->children : Symbol(Directory.children, Decl(typeGuardOfFormThisMember.ts, 20, 50))
-	}
-	else if (file.isNetworked) {
->file.isNetworked : Symbol(FileSystemObject.isNetworked, Decl(typeGuardOfFormThisMember.ts, 12, 3))
->file : Symbol(file, Decl(typeGuardOfFormThisMember.ts, 27, 4))
->isNetworked : Symbol(FileSystemObject.isNetworked, Decl(typeGuardOfFormThisMember.ts, 12, 3))
-
-		file.host;
->file.host : Symbol(Networked.host, Decl(typeGuardOfFormThisMember.ts, 23, 29))
->file : Symbol(file, Decl(typeGuardOfFormThisMember.ts, 27, 4))
->host : Symbol(Networked.host, Decl(typeGuardOfFormThisMember.ts, 23, 29))
-	}
-	
-	interface GenericLeadGuard<T> extends GenericGuard<T> {
->GenericLeadGuard : Symbol(GenericLeadGuard, Decl(typeGuardOfFormThisMember.ts, 44, 2))
->T : Symbol(T, Decl(typeGuardOfFormThisMember.ts, 46, 28))
->GenericGuard : Symbol(GenericGuard, Decl(typeGuardOfFormThisMember.ts, 52, 2))
->T : Symbol(T, Decl(typeGuardOfFormThisMember.ts, 46, 28))
-
-		lead(): void;
->lead : Symbol(lead, Decl(typeGuardOfFormThisMember.ts, 46, 56))
-	}
-	
-	interface GenericFollowerGuard<T> extends GenericGuard<T> {
->GenericFollowerGuard : Symbol(GenericFollowerGuard, Decl(typeGuardOfFormThisMember.ts, 48, 2))
->T : Symbol(T, Decl(typeGuardOfFormThisMember.ts, 50, 32))
->GenericGuard : Symbol(GenericGuard, Decl(typeGuardOfFormThisMember.ts, 52, 2))
->T : Symbol(T, Decl(typeGuardOfFormThisMember.ts, 50, 32))
-
-		follow(): void;
->follow : Symbol(follow, Decl(typeGuardOfFormThisMember.ts, 50, 60))
-	}
-	
-	interface GenericGuard<T> {
->GenericGuard : Symbol(GenericGuard, Decl(typeGuardOfFormThisMember.ts, 52, 2))
->T : Symbol(T, Decl(typeGuardOfFormThisMember.ts, 54, 24))
-
-		target: T;
->target : Symbol(target, Decl(typeGuardOfFormThisMember.ts, 54, 28))
->T : Symbol(T, Decl(typeGuardOfFormThisMember.ts, 54, 24))
-
-		isLeader: this is (GenericLeadGuard<T>);
->isLeader : Symbol(isLeader, Decl(typeGuardOfFormThisMember.ts, 55, 12))
->GenericLeadGuard : Symbol(GenericLeadGuard, Decl(typeGuardOfFormThisMember.ts, 44, 2))
->T : Symbol(T, Decl(typeGuardOfFormThisMember.ts, 54, 24))
-
-		isFollower: this is GenericFollowerGuard<T>;
->isFollower : Symbol(isFollower, Decl(typeGuardOfFormThisMember.ts, 56, 42))
->GenericFollowerGuard : Symbol(GenericFollowerGuard, Decl(typeGuardOfFormThisMember.ts, 48, 2))
->T : Symbol(T, Decl(typeGuardOfFormThisMember.ts, 54, 24))
-	}
-
-	let guard: GenericGuard<File>;
->guard : Symbol(guard, Decl(typeGuardOfFormThisMember.ts, 60, 4))
->GenericGuard : Symbol(GenericGuard, Decl(typeGuardOfFormThisMember.ts, 52, 2))
->File : Symbol(File, Decl(typeGuardOfFormThisMember.ts, 15, 2))
-
-	if (guard.isLeader) {
->guard.isLeader : Symbol(GenericGuard.isLeader, Decl(typeGuardOfFormThisMember.ts, 55, 12))
->guard : Symbol(guard, Decl(typeGuardOfFormThisMember.ts, 60, 4))
->isLeader : Symbol(GenericGuard.isLeader, Decl(typeGuardOfFormThisMember.ts, 55, 12))
-
-		guard.lead();
->guard.lead : Symbol(GenericLeadGuard.lead, Decl(typeGuardOfFormThisMember.ts, 46, 56))
->guard : Symbol(guard, Decl(typeGuardOfFormThisMember.ts, 60, 4))
->lead : Symbol(GenericLeadGuard.lead, Decl(typeGuardOfFormThisMember.ts, 46, 56))
-	}
-	else if (guard.isFollower) {
->guard.isFollower : Symbol(GenericGuard.isFollower, Decl(typeGuardOfFormThisMember.ts, 56, 42))
->guard : Symbol(guard, Decl(typeGuardOfFormThisMember.ts, 60, 4))
->isFollower : Symbol(GenericGuard.isFollower, Decl(typeGuardOfFormThisMember.ts, 56, 42))
-
-		guard.follow();
->guard.follow : Symbol(GenericFollowerGuard.follow, Decl(typeGuardOfFormThisMember.ts, 50, 60))
->guard : Symbol(guard, Decl(typeGuardOfFormThisMember.ts, 60, 4))
->follow : Symbol(GenericFollowerGuard.follow, Decl(typeGuardOfFormThisMember.ts, 50, 60))
-	}
-
-	interface SpecificGuard {
->SpecificGuard : Symbol(SpecificGuard, Decl(typeGuardOfFormThisMember.ts, 66, 2))
-
-		isMoreSpecific: this is MoreSpecificGuard;
->isMoreSpecific : Symbol(isMoreSpecific, Decl(typeGuardOfFormThisMember.ts, 68, 26))
->MoreSpecificGuard : Symbol(MoreSpecificGuard, Decl(typeGuardOfFormThisMember.ts, 70, 2))
-	}
-
-	interface MoreSpecificGuard extends SpecificGuard {
->MoreSpecificGuard : Symbol(MoreSpecificGuard, Decl(typeGuardOfFormThisMember.ts, 70, 2))
->SpecificGuard : Symbol(SpecificGuard, Decl(typeGuardOfFormThisMember.ts, 66, 2))
-
-		do(): void;
->do : Symbol(do, Decl(typeGuardOfFormThisMember.ts, 72, 52))
-	}
-
-	let general: SpecificGuard;
->general : Symbol(general, Decl(typeGuardOfFormThisMember.ts, 76, 4))
->SpecificGuard : Symbol(SpecificGuard, Decl(typeGuardOfFormThisMember.ts, 66, 2))
-
-	if (general.isMoreSpecific) {
->general.isMoreSpecific : Symbol(SpecificGuard.isMoreSpecific, Decl(typeGuardOfFormThisMember.ts, 68, 26))
->general : Symbol(general, Decl(typeGuardOfFormThisMember.ts, 76, 4))
->isMoreSpecific : Symbol(SpecificGuard.isMoreSpecific, Decl(typeGuardOfFormThisMember.ts, 68, 26))
-
-		general.do();
->general.do : Symbol(MoreSpecificGuard.do, Decl(typeGuardOfFormThisMember.ts, 72, 52))
->general : Symbol(general, Decl(typeGuardOfFormThisMember.ts, 76, 4))
->do : Symbol(MoreSpecificGuard.do, Decl(typeGuardOfFormThisMember.ts, 72, 52))
-	}
-}
-

tests/baselines/reference/typeGuardOfFormThisMember.types

@@ -1,254 +0,0 @@
-=== tests/cases/conformance/expressions/typeGuards/typeGuardOfFormThisMember.ts ===
-// There's a 'File' class in the stdlib, wrap with a namespace to avoid collision
-namespace Test {
->Test : typeof Test
-
-	export class FileSystemObject {
->FileSystemObject : FileSystemObject
-
-		isFSO: this is FileSystemObject;
->isFSO : this is FileSystemObject
->FileSystemObject : FileSystemObject
-
-		get isFile(): this is File {
->isFile : this is File
->File : File
-
-			return this instanceof File;
->this instanceof File : boolean
->this : this
->File : typeof File
-		}
-		set isFile(param) {
->isFile : this is File
->param : boolean
-
-			// noop
-		}
-		get isDirectory(): this is Directory {
->isDirectory : this is Directory
->Directory : Directory
-
-			return this instanceof Directory;
->this instanceof Directory : boolean
->this : this
->Directory : typeof Directory
-		}
-		isNetworked: this is (Networked & this);
->isNetworked : this is Networked & this
->Networked : Networked
-
-		constructor(public path: string) {}
->path : string
-	}
-
-	export class File extends FileSystemObject {
->File : File
->FileSystemObject : FileSystemObject
-
-		constructor(path: string, public content: string) { super(path); }
->path : string
->content : string
->super(path) : void
->super : typeof FileSystemObject
->path : string
-	}
-	export class Directory extends FileSystemObject {
->Directory : Directory
->FileSystemObject : FileSystemObject
-
-		children: FileSystemObject[];
->children : FileSystemObject[]
->FileSystemObject : FileSystemObject
-	}
-	export interface Networked {
->Networked : Networked
-
-		host: string;
->host : string
-	}
-
-	let file: FileSystemObject = new File("foo/bar.txt", "foo");
->file : FileSystemObject
->FileSystemObject : FileSystemObject
->new File("foo/bar.txt", "foo") : File
->File : typeof File
->"foo/bar.txt" : string
->"foo" : string
-
-	file.isNetworked = false;
->file.isNetworked = false : boolean
->file.isNetworked : this is Networked & FileSystemObject
->file : FileSystemObject
->isNetworked : this is Networked & FileSystemObject
->false : boolean
-
-	file.isFSO = file.isFile;
->file.isFSO = file.isFile : this is File
->file.isFSO : this is FileSystemObject
->file : FileSystemObject
->isFSO : this is FileSystemObject
->file.isFile : this is File
->file : FileSystemObject
->isFile : this is File
-
-	file.isFile = true;
->file.isFile = true : boolean
->file.isFile : this is File
->file : FileSystemObject
->isFile : this is File
->true : boolean
-
-	let x = file.isFile;
->x : boolean
->file.isFile : this is File
->file : FileSystemObject
->isFile : this is File
-
-	if (file.isFile) {
->file.isFile : this is File
->file : FileSystemObject
->isFile : this is File
-
-		file.content;
->file.content : string
->file : File
->content : string
-
-		if (file.isNetworked) {
->file.isNetworked : this is Networked & File
->file : File
->isNetworked : this is Networked & File
-
-			file.host;
->file.host : string
->file : Networked & File
->host : string
-
-			file.content;
->file.content : string
->file : Networked & File
->content : string
-		}
-	}
-	else if (file.isDirectory) {
->file.isDirectory : this is Directory
->file : FileSystemObject
->isDirectory : this is Directory
-
-		file.children;
->file.children : FileSystemObject[]
->file : Directory
->children : FileSystemObject[]
-	}
-	else if (file.isNetworked) {
->file.isNetworked : this is Networked & FileSystemObject
->file : FileSystemObject
->isNetworked : this is Networked & FileSystemObject
-
-		file.host;
->file.host : string
->file : Networked & FileSystemObject
->host : string
-	}
-	
-	interface GenericLeadGuard<T> extends GenericGuard<T> {
->GenericLeadGuard : GenericLeadGuard<T>
->T : T
->GenericGuard : GenericGuard<T>
->T : T
-
-		lead(): void;
->lead : () => void
-	}
-	
-	interface GenericFollowerGuard<T> extends GenericGuard<T> {
->GenericFollowerGuard : GenericFollowerGuard<T>
->T : T
->GenericGuard : GenericGuard<T>
->T : T
-
-		follow(): void;
->follow : () => void
-	}
-	
-	interface GenericGuard<T> {
->GenericGuard : GenericGuard<T>
->T : T
-
-		target: T;
->target : T
->T : T
-
-		isLeader: this is (GenericLeadGuard<T>);
->isLeader : this is GenericLeadGuard<T>
->GenericLeadGuard : GenericLeadGuard<T>
->T : T
-
-		isFollower: this is GenericFollowerGuard<T>;
->isFollower : this is GenericFollowerGuard<T>
->GenericFollowerGuard : GenericFollowerGuard<T>
->T : T
-	}
-
-	let guard: GenericGuard<File>;
->guard : GenericGuard<File>
->GenericGuard : GenericGuard<T>
->File : File
-
-	if (guard.isLeader) {
->guard.isLeader : this is GenericLeadGuard<File>
->guard : GenericGuard<File>
->isLeader : this is GenericLeadGuard<File>
-
-		guard.lead();
->guard.lead() : void
->guard.lead : () => void
->guard : GenericLeadGuard<File>
->lead : () => void
-	}
-	else if (guard.isFollower) {
->guard.isFollower : this is GenericFollowerGuard<File>
->guard : GenericGuard<File>
->isFollower : this is GenericFollowerGuard<File>
-
-		guard.follow();
->guard.follow() : void
->guard.follow : () => void
->guard : GenericFollowerGuard<File>
->follow : () => void
-	}
-
-	interface SpecificGuard {
->SpecificGuard : SpecificGuard
-
-		isMoreSpecific: this is MoreSpecificGuard;
->isMoreSpecific : this is MoreSpecificGuard
->MoreSpecificGuard : MoreSpecificGuard
-	}
-
-	interface MoreSpecificGuard extends SpecificGuard {
->MoreSpecificGuard : MoreSpecificGuard
->SpecificGuard : SpecificGuard
-
-		do(): void;
->do : () => void
-	}
-
-	let general: SpecificGuard;
->general : SpecificGuard
->SpecificGuard : SpecificGuard
-
-	if (general.isMoreSpecific) {
->general.isMoreSpecific : this is MoreSpecificGuard
->general : SpecificGuard
->isMoreSpecific : this is MoreSpecificGuard
-
-		general.do();
->general.do() : void
->general.do : () => void
->general : MoreSpecificGuard
->do : () => void
-	}
-}
-

tests/baselines/reference/typeGuardOfFormThisMemberErrors.errors.txt

@@ -1,27 +1,32 @@
-tests/cases/conformance/expressions/typeGuards/typeGuardOfFormThisMemberErrors.ts(29,2): error TS1226: Type predicate 'this is File' is not assignable to 'this is Networked & FileSystemObject'.
-  Type 'File' is not assignable to type 'Networked & FileSystemObject'.
-    Type 'File' is not assignable to type 'Networked'.
-      Property 'host' is missing in type 'File'.
-tests/cases/conformance/expressions/typeGuards/typeGuardOfFormThisMemberErrors.ts(31,2): error TS1226: Type predicate 'this is FileSystemObject' is not assignable to 'this is File'.
-  Type 'FileSystemObject' is not assignable to type 'File'.
-    Property 'content' is missing in type 'FileSystemObject'.
+tests/cases/conformance/expressions/typeGuards/typeGuardOfFormThisMemberErrors.ts(4,10): error TS1228: A type predicate is only allowed in return type position for functions and methods.
+tests/cases/conformance/expressions/typeGuards/typeGuardOfFormThisMemberErrors.ts(5,17): error TS1228: A type predicate is only allowed in return type position for functions and methods.
+tests/cases/conformance/expressions/typeGuards/typeGuardOfFormThisMemberErrors.ts(11,22): error TS1228: A type predicate is only allowed in return type position for functions and methods.
+tests/cases/conformance/expressions/typeGuards/typeGuardOfFormThisMemberErrors.ts(14,16): error TS1228: A type predicate is only allowed in return type position for functions and methods.
 
 
-==== tests/cases/conformance/expressions/typeGuards/typeGuardOfFormThisMemberErrors.ts (2 errors) ====
+==== tests/cases/conformance/expressions/typeGuards/typeGuardOfFormThisMemberErrors.ts (4 errors) ====
     // There's a 'File' class in the stdlib, wrap with a namespace to avoid collision
     namespace Test {
     	export class FileSystemObject {
     		isFSO: this is FileSystemObject;
+    		       ~~~~~~~~~~~~~~~~~~~~~~~~
+!!! error TS1228: A type predicate is only allowed in return type position for functions and methods.
     		get isFile(): this is File {
+    		              ~~~~~~~~~~~~
+!!! error TS1228: A type predicate is only allowed in return type position for functions and methods.
     			return this instanceof File;
     		}
     		set isFile(param) {
     			// noop
     		}
     		get isDirectory(): this is Directory {
+    		                   ~~~~~~~~~~~~~~~~~
+!!! error TS1228: A type predicate is only allowed in return type position for functions and methods.
     			return this instanceof Directory;
     		}
     		isNetworked: this is (Networked & this);
+    		             ~~~~~~~~~~~~~~~~~~~~~~~~~~
+!!! error TS1228: A type predicate is only allowed in return type position for functions and methods.
     		constructor(public path: string) {}
     	}
     
@@ -37,15 +42,6 @@ tests/cases/conformance/expressions/typeGuards/typeGuardOfFormThisMemberErrors.t
     
     	let file: FileSystemObject = new File("foo/bar.txt", "foo");
     	file.isNetworked = file.isFile;
-    	~~~~~~~~~~~~~~~~
-!!! error TS1226: Type predicate 'this is File' is not assignable to 'this is Networked & FileSystemObject'.
-!!! error TS1226:   Type 'File' is not assignable to type 'Networked & FileSystemObject'.
-!!! error TS1226:     Type 'File' is not assignable to type 'Networked'.
-!!! error TS1226:       Property 'host' is missing in type 'File'.
     	file.isFSO = file.isNetworked;
     	file.isFile = file.isFSO;
-    	~~~~~~~~~~~
-!!! error TS1226: Type predicate 'this is FileSystemObject' is not assignable to 'this is File'.
-!!! error TS1226:   Type 'FileSystemObject' is not assignable to type 'File'.
-!!! error TS1226:     Property 'content' is missing in type 'FileSystemObject'.
     }

tests/baselines/reference/typePredicateOnVariableDeclaration01.errors.txt

@@ -0,0 +1,8 @@
+tests/cases/conformance/expressions/typeGuards/typePredicateOnVariableDeclaration01.ts(2,8): error TS1228: A type predicate is only allowed in return type position for functions and methods.
+
+
+==== tests/cases/conformance/expressions/typeGuards/typePredicateOnVariableDeclaration01.ts (1 errors) ====
+    
+    var x: this is string;
+           ~~~~~~~~~~~~~~
+!!! error TS1228: A type predicate is only allowed in return type position for functions and methods.

tests/baselines/reference/typePredicateOnVariableDeclaration02.errors.txt

@@ -0,0 +1,20 @@
+tests/cases/conformance/expressions/typeGuards/typePredicateOnVariableDeclaration02.ts(2,8): error TS2304: Cannot find name 'z'.
+tests/cases/conformance/expressions/typeGuards/typePredicateOnVariableDeclaration02.ts(2,8): error TS4025: Exported variable 'y' has or is using private name 'z'.
+tests/cases/conformance/expressions/typeGuards/typePredicateOnVariableDeclaration02.ts(2,10): error TS1005: '=' expected.
+tests/cases/conformance/expressions/typeGuards/typePredicateOnVariableDeclaration02.ts(2,10): error TS2304: Cannot find name 'is'.
+tests/cases/conformance/expressions/typeGuards/typePredicateOnVariableDeclaration02.ts(2,13): error TS1005: ',' expected.
+
+
+==== tests/cases/conformance/expressions/typeGuards/typePredicateOnVariableDeclaration02.ts (5 errors) ====
+    
+    var y: z is number;
+           ~
+!!! error TS2304: Cannot find name 'z'.
+           ~
+!!! error TS4025: Exported variable 'y' has or is using private name 'z'.
+             ~~
+!!! error TS1005: '=' expected.
+             ~~
+!!! error TS2304: Cannot find name 'is'.
+                ~~~~~~
+!!! error TS1005: ',' expected.

tests/baselines/reference/unionAndIntersectionInference1.types

@@ -110,7 +110,7 @@ function foo1<a>(value: void|a): void {
 >a : a
 
     if (isVoid(value)) {
->isVoid(value) : value is void
+>isVoid(value) : boolean
 >isVoid : <a>(value: void | a) => value is void
 >value : void | a
 
@@ -130,7 +130,7 @@ function baz1<a>(value: void|a): void {
 >a : a
 
       if (isNonVoid(value)) {
->isNonVoid(value) : value is a
+>isNonVoid(value) : boolean
 >isNonVoid : <a>(value: void | a) => value is a
 >value : void | a