tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts(16,15): error TS2339: Property 'n' does not exist on type 'void'.
tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts(39,21): error TS2339: Property 'a' does not exist on type 'void'.
tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts(49,1): error TS2684: The 'this' context of type 'void' is not assignable to method's 'this' of type '{ a: number; }'.
tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts(51,1): error TS2684: The 'this' context of type 'void' is not assignable to method's 'this' of type 'I'.
tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts(56,21): error TS2339: Property 'notFound' does not exist on type '{ y: number; }'.
tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts(59,21): error TS2339: Property 'notSpecified' does not exist on type 'void'.
tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts(61,79): error TS2322: Type '{ y: number; explicitStructural: (this: { y: number; }, x: number) => number; }' is not assignable to type '{ y: number; f: (this: { y: number; }, x: number) => number; }'.
  Object literal may only specify known properties, and 'explicitStructural' does not exist in type '{ y: number; f: (this: { y: number; }, x: number) => number; }'.
tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts(62,97): error TS2322: Type '{ y: string; explicitStructural: (this: { y: number; }, x: number) => number; }' is not assignable to type '{ y: string; f: (this: { y: number; }, x: number) => number; }'.
  Object literal may only specify known properties, and 'explicitStructural' does not exist in type '{ y: string; f: (this: { y: number; }, x: number) => number; }'.
tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts(63,110): error TS2322: Type '{ wrongName: number; explicitStructural: (this: { y: number; }, x: number) => number; }' is not assignable to type '{ wrongName: number; f: (this: { y: number; }, x: number) => number; }'.
  Object literal may only specify known properties, and 'explicitStructural' does not exist in type '{ wrongName: number; f: (this: { y: number; }, x: number) => number; }'.
tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts(65,1): error TS2554: Expected 1 arguments, but got 0.
tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts(66,6): error TS2345: Argument of type '"wrong type"' is not assignable to parameter of type 'number'.
tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts(67,1): error TS2554: Expected 1 arguments, but got 2.
tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts(68,1): error TS2684: The 'this' context of type '{ y: string; f: (this: { y: number; }, x: number) => number; }' is not assignable to method's 'this' of type '{ y: number; }'.
  Types of property 'y' are incompatible.
    Type 'string' is not assignable to type 'number'.
tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts(69,1): error TS2684: The 'this' context of type '{ wrongName: number; f: (this: { y: number; }, x: number) => number; }' is not assignable to method's 'this' of type '{ y: number; }'.
  Property 'y' is missing in type '{ wrongName: number; f: (this: { y: number; }, x: number) => number; }' but required in type '{ y: number; }'.
tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts(72,1): error TS2554: Expected 1 arguments, but got 0.
tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts(73,13): error TS2345: Argument of type '"wrong type"' is not assignable to parameter of type 'number'.
tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts(74,1): error TS2554: Expected 1 arguments, but got 2.
tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts(75,1): error TS2554: Expected 1 arguments, but got 0.
tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts(76,16): error TS2345: Argument of type '"wrong type 2"' is not assignable to parameter of type 'number'.
tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts(77,1): error TS2554: Expected 1 arguments, but got 2.
tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts(78,1): error TS2554: Expected 1 arguments, but got 0.
tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts(79,16): error TS2345: Argument of type '"wrong type 2"' is not assignable to parameter of type 'number'.
tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts(80,1): error TS2554: Expected 1 arguments, but got 2.
tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts(81,1): error TS2554: Expected 1 arguments, but got 0.
tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts(82,20): error TS2345: Argument of type '"wrong type 3"' is not assignable to parameter of type 'number'.
tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts(83,1): error TS2554: Expected 1 arguments, but got 2.
tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts(86,5): error TS2322: Type '(this: { y: number; }, x: number) => number' is not assignable to type '(this: void, x: number) => number'.
  The 'this' types of each signature are incompatible.
    Type 'void' is not assignable to type '{ y: number; }'.
tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts(107,1): error TS2322: Type '(this: D, m: number) => number' is not assignable to type '(this: C, m: number) => number'.
  The 'this' types of each signature are incompatible.
    Type 'C' is missing the following properties from type 'D': x, explicitD
tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts(108,1): error TS2322: Type '(this: { x: number; }, m: number) => number' is not assignable to type '(this: { n: number; }, m: number) => number'.
  The 'this' types of each signature are incompatible.
    Property 'x' is missing in type '{ n: number; }' but required in type '{ x: number; }'.
tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts(110,1): error TS2322: Type '(this: D, m: number) => number' is not assignable to type '(this: C, m: number) => number'.
  The 'this' types of each signature are incompatible.
    Type 'C' is not assignable to type 'D'.
tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts(111,1): error TS2322: Type '(this: D, m: number) => number' is not assignable to type '(this: C, m: number) => number'.
  The 'this' types of each signature are incompatible.
    Type 'C' is not assignable to type 'D'.
tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts(112,1): error TS2322: Type '(this: D, m: number) => number' is not assignable to type '(this: C, m: number) => number'.
  The 'this' types of each signature are incompatible.
    Type 'C' is not assignable to type 'D'.
tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts(113,1): error TS2322: Type '(this: D, m: number) => number' is not assignable to type '(this: C, m: number) => number'.
  The 'this' types of each signature are incompatible.
    Type 'C' is not assignable to type 'D'.
tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts(114,1): error TS2322: Type '(this: D, m: number) => number' is not assignable to type '(this: { n: number; }, m: number) => number'.
  The 'this' types of each signature are incompatible.
    Type '{ n: number; }' is missing the following properties from type 'D': x, explicitThis, explicitD
tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts(115,1): error TS2322: Type '(this: D, m: number) => number' is not assignable to type '(this: C, m: number) => number'.
tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts(116,1): error TS2322: Type '(this: D, m: number) => number' is not assignable to type '(this: void, m: number) => number'.
  The 'this' types of each signature are incompatible.
    Type 'void' is not assignable to type 'D'.
tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts(117,1): error TS2322: Type '(this: D, m: number) => number' is not assignable to type '(this: void, m: number) => number'.
  The 'this' types of each signature are incompatible.
    Type 'void' is not assignable to type 'D'.
tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts(125,69): error TS2339: Property 'x' does not exist on type 'typeof Base1'.
tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts(145,1): error TS2322: Type '(this: Base2) => number' is not assignable to type '(this: Base1) => number'.
  The 'this' types of each signature are incompatible.
    Property 'y' is missing in type 'Base1' but required in type 'Base2'.
tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts(146,1): error TS2322: Type '(this: Base2) => number' is not assignable to type '(this: Base1) => number'.
  The 'this' types of each signature are incompatible.
    Type 'Base1' is not assignable to type 'Base2'.
tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts(148,1): error TS2322: Type '(this: Base2) => number' is not assignable to type '(this: Base1) => number'.
tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts(154,16): error TS2679: A function that is called with the 'new' keyword cannot have a 'this' type that is 'void'.
tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts(158,17): error TS2681: A constructor cannot have a 'this' parameter.
tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts(162,9): error TS2681: A constructor cannot have a 'this' parameter.
tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts(164,31): error TS2681: A constructor cannot have a 'this' parameter.
tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts(165,30): error TS2680: A 'this' parameter must be the first parameter.
tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts(168,26): error TS1003: Identifier expected.
tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts(168,26): error TS2680: A 'this' parameter must be the first parameter.
tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts(169,23): error TS1003: Identifier expected.
tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts(169,23): error TS2680: A 'this' parameter must be the first parameter.
tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts(170,23): error TS1005: ',' expected.
tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts(171,28): error TS1003: Identifier expected.
tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts(171,28): error TS2680: A 'this' parameter must be the first parameter.
tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts(172,30): error TS1005: ',' expected.
tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts(172,32): error TS1003: Identifier expected.
tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts(172,37): error TS1005: ',' expected.
tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts(172,38): error TS1109: Expression expected.
tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts(172,39): error TS1005: ';' expected.
tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts(172,40): error TS1128: Declaration or statement expected.
tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts(172,42): error TS2693: 'number' only refers to a type, but is being used as a value here.
tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts(172,49): error TS1005: ';' expected.
tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts(175,23): error TS2730: An arrow function cannot have a 'this' parameter.
tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts(176,16): error TS2730: An arrow function cannot have a 'this' parameter.
tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts(177,19): error TS2730: An arrow function cannot have a 'this' parameter.
tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts(178,22): error TS2730: An arrow function cannot have a 'this' parameter.


==== tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts (65 errors) ====
    class C {
        n: number;
        explicitThis(this: this, m: number): number {
            return this.n + m;
        }
        implicitThis(m: number): number {
            return this.n + m;
        }
        explicitC(this: C, m: number): number {
            return this.n + m;
        }
        explicitProperty(this: {n: number}, m: number): number {
            return this.n + m;
        }
        explicitVoid(this: void, m: number): number {
    		return this.n + m; // 'n' doesn't exist on type 'void'.
    		            ~
!!! error TS2339: Property 'n' does not exist on type 'void'.
        }
    }
    class D {
    	x: number;
    	explicitThis(this: this, m: number): number {
    		return this.x + m;
    	}
    	explicitD(this: D, m: number): number {
    		return this.x + m;
    	}
    }
    interface I {
        a: number;
        explicitVoid1(this: void): number;
        explicitVoid2(this: void): number;
        explicitStructural(this: {a: number}): number;
        explicitInterface(this: I): number;
        explicitThis(this: this): number; // TODO: Allow `this` types for interfaces
    }
    let impl: I = {
        a: 12,
        explicitVoid1() {
            return this.a; // error, no 'a' in 'void'
                        ~
!!! error TS2339: Property 'a' does not exist on type 'void'.
        },
        explicitVoid2: () => this.a, // ok, `this:any` because it refers to an outer object
        explicitStructural: () => 12,
        explicitInterface: () => 12,
        explicitThis() {
            return this.a;
        },
    }
    let implExplicitStructural = impl.explicitStructural;
    implExplicitStructural(); // error, no 'a' in 'void'
    ~~~~~~~~~~~~~~~~~~~~~~~~
!!! error TS2684: The 'this' context of type 'void' is not assignable to method's 'this' of type '{ a: number; }'.
    let implExplicitInterface = impl.explicitInterface;
    implExplicitInterface(); // error, no 'a' in 'void' 
    ~~~~~~~~~~~~~~~~~~~~~~~
!!! error TS2684: The 'this' context of type 'void' is not assignable to method's 'this' of type 'I'.
    function explicitStructural(this: { y: number }, x: number): number {
        return x + this.y;
    }
    function propertyName(this: { y: number }, x: number): number {
        return x + this.notFound;
                        ~~~~~~~~
!!! error TS2339: Property 'notFound' does not exist on type '{ y: number; }'.
    }
    function voidThisSpecified(this: void, x: number): number {
        return x + this.notSpecified;
                        ~~~~~~~~~~~~
!!! error TS2339: Property 'notSpecified' does not exist on type 'void'.
    }
    let ok: {y: number, f: (this: { y: number }, x: number) => number} = { y: 12, explicitStructural };
                                                                                  ~~~~~~~~~~~~~~~~~~
!!! error TS2322: Type '{ y: number; explicitStructural: (this: { y: number; }, x: number) => number; }' is not assignable to type '{ y: number; f: (this: { y: number; }, x: number) => number; }'.
!!! error TS2322:   Object literal may only specify known properties, and 'explicitStructural' does not exist in type '{ y: number; f: (this: { y: number; }, x: number) => number; }'.
    let wrongPropertyType: {y: string, f: (this: { y: number }, x: number) => number} = { y: 'foo', explicitStructural };
                                                                                                    ~~~~~~~~~~~~~~~~~~
!!! error TS2322: Type '{ y: string; explicitStructural: (this: { y: number; }, x: number) => number; }' is not assignable to type '{ y: string; f: (this: { y: number; }, x: number) => number; }'.
!!! error TS2322:   Object literal may only specify known properties, and 'explicitStructural' does not exist in type '{ y: string; f: (this: { y: number; }, x: number) => number; }'.
    let wrongPropertyName: {wrongName: number, f: (this: { y: number }, x: number) => number} = { wrongName: 12, explicitStructural };
                                                                                                                 ~~~~~~~~~~~~~~~~~~
!!! error TS2322: Type '{ wrongName: number; explicitStructural: (this: { y: number; }, x: number) => number; }' is not assignable to type '{ wrongName: number; f: (this: { y: number; }, x: number) => number; }'.
!!! error TS2322:   Object literal may only specify known properties, and 'explicitStructural' does not exist in type '{ wrongName: number; f: (this: { y: number; }, x: number) => number; }'.
    
    ok.f(); // not enough arguments
    ~~~~~~
!!! error TS2554: Expected 1 arguments, but got 0.
!!! related TS6210 tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts:61:46: An argument for 'x' was not provided.
    ok.f('wrong type');
         ~~~~~~~~~~~~
!!! error TS2345: Argument of type '"wrong type"' is not assignable to parameter of type 'number'.
    ok.f(13, 'too many arguments');
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
!!! error TS2554: Expected 1 arguments, but got 2.
    wrongPropertyType.f(13);
    ~~~~~~~~~~~~~~~~~
!!! error TS2684: The 'this' context of type '{ y: string; f: (this: { y: number; }, x: number) => number; }' is not assignable to method's 'this' of type '{ y: number; }'.
!!! error TS2684:   Types of property 'y' are incompatible.
!!! error TS2684:     Type 'string' is not assignable to type 'number'.
    wrongPropertyName.f(13);
    ~~~~~~~~~~~~~~~~~
!!! error TS2684: The 'this' context of type '{ wrongName: number; f: (this: { y: number; }, x: number) => number; }' is not assignable to method's 'this' of type '{ y: number; }'.
!!! error TS2684:   Property 'y' is missing in type '{ wrongName: number; f: (this: { y: number; }, x: number) => number; }' but required in type '{ y: number; }'.
!!! related TS2728 tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts:63:56: 'y' is declared here.
    
    let c = new C();
    c.explicitC(); // not enough arguments
    ~~~~~~~~~~~~~
!!! error TS2554: Expected 1 arguments, but got 0.
!!! related TS6210 tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts:9:24: An argument for 'm' was not provided.
    c.explicitC('wrong type');
                ~~~~~~~~~~~~
!!! error TS2345: Argument of type '"wrong type"' is not assignable to parameter of type 'number'.
    c.explicitC(13, 'too many arguments');
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
!!! error TS2554: Expected 1 arguments, but got 2.
    c.explicitThis(); // not enough arguments
    ~~~~~~~~~~~~~~~~
!!! error TS2554: Expected 1 arguments, but got 0.
!!! related TS6210 tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts:3:30: An argument for 'm' was not provided.
    c.explicitThis('wrong type 2');
                   ~~~~~~~~~~~~~~
!!! error TS2345: Argument of type '"wrong type 2"' is not assignable to parameter of type 'number'.
    c.explicitThis(14, 'too many arguments 2');
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
!!! error TS2554: Expected 1 arguments, but got 2.
    c.implicitThis(); // not enough arguments
    ~~~~~~~~~~~~~~~~
!!! error TS2554: Expected 1 arguments, but got 0.
!!! related TS6210 tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts:6:18: An argument for 'm' was not provided.
    c.implicitThis('wrong type 2');
                   ~~~~~~~~~~~~~~
!!! error TS2345: Argument of type '"wrong type 2"' is not assignable to parameter of type 'number'.
    c.implicitThis(14, 'too many arguments 2');
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
!!! error TS2554: Expected 1 arguments, but got 2.
    c.explicitProperty(); // not enough arguments
    ~~~~~~~~~~~~~~~~~~~~
!!! error TS2554: Expected 1 arguments, but got 0.
!!! related TS6210 tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts:12:41: An argument for 'm' was not provided.
    c.explicitProperty('wrong type 3');
                       ~~~~~~~~~~~~~~
!!! error TS2345: Argument of type '"wrong type 3"' is not assignable to parameter of type 'number'.
    c.explicitProperty(15, 'too many arguments 3');
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
!!! error TS2554: Expected 1 arguments, but got 2.
    
    // oops, this triggers contextual typing, which needs to be updated to understand that =>'s `this` is void.
    let specifiedToVoid: (this: void, x: number) => number = explicitStructural;
        ~~~~~~~~~~~~~~~
!!! error TS2322: Type '(this: { y: number; }, x: number) => number' is not assignable to type '(this: void, x: number) => number'.
!!! error TS2322:   The 'this' types of each signature are incompatible.
!!! error TS2322:     Type 'void' is not assignable to type '{ y: number; }'.
    
    let reconstructed: { 
        n: number,
        explicitThis(this: C, m: number): number, // note: this: this is not allowed in an object literal type.
        explicitC(this: C, m: number): number,
        explicitProperty: (this: {n : number}, m: number) => number,
        explicitVoid(this: void, m: number): number,
    } = { 
        n: 12,
        explicitThis: c.explicitThis,
        explicitC: c.explicitC,
        explicitProperty: c.explicitProperty,
        explicitVoid: c.explicitVoid
    };;
    
    // lambdas have this: void for assignability purposes (and this unbound (free) for body checking)
    let d = new D();
    let explicitXProperty: (this: { x: number }, m: number) => number;
    
    // from differing object types
    c.explicitC = function(this: D, m: number) { return this.x + m };
    ~~~~~~~~~~~
!!! error TS2322: Type '(this: D, m: number) => number' is not assignable to type '(this: C, m: number) => number'.
!!! error TS2322:   The 'this' types of each signature are incompatible.
!!! error TS2322:     Type 'C' is missing the following properties from type 'D': x, explicitD
    c.explicitProperty = explicitXProperty;
    ~~~~~~~~~~~~~~~~~~
!!! error TS2322: Type '(this: { x: number; }, m: number) => number' is not assignable to type '(this: { n: number; }, m: number) => number'.
!!! error TS2322:   The 'this' types of each signature are incompatible.
!!! error TS2322:     Property 'x' is missing in type '{ n: number; }' but required in type '{ x: number; }'.
!!! related TS2728 tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts:104:33: 'x' is declared here.
    
    c.explicitC = d.explicitD;
    ~~~~~~~~~~~
!!! error TS2322: Type '(this: D, m: number) => number' is not assignable to type '(this: C, m: number) => number'.
!!! error TS2322:   The 'this' types of each signature are incompatible.
!!! error TS2322:     Type 'C' is not assignable to type 'D'.
    c.explicitC = d.explicitThis;
    ~~~~~~~~~~~
!!! error TS2322: Type '(this: D, m: number) => number' is not assignable to type '(this: C, m: number) => number'.
!!! error TS2322:   The 'this' types of each signature are incompatible.
!!! error TS2322:     Type 'C' is not assignable to type 'D'.
    c.explicitThis = d.explicitD;
    ~~~~~~~~~~~~~~
!!! error TS2322: Type '(this: D, m: number) => number' is not assignable to type '(this: C, m: number) => number'.
!!! error TS2322:   The 'this' types of each signature are incompatible.
!!! error TS2322:     Type 'C' is not assignable to type 'D'.
    c.explicitThis = d.explicitThis;
    ~~~~~~~~~~~~~~
!!! error TS2322: Type '(this: D, m: number) => number' is not assignable to type '(this: C, m: number) => number'.
!!! error TS2322:   The 'this' types of each signature are incompatible.
!!! error TS2322:     Type 'C' is not assignable to type 'D'.
    c.explicitProperty = d.explicitD;
    ~~~~~~~~~~~~~~~~~~
!!! error TS2322: Type '(this: D, m: number) => number' is not assignable to type '(this: { n: number; }, m: number) => number'.
!!! error TS2322:   The 'this' types of each signature are incompatible.
!!! error TS2322:     Type '{ n: number; }' is missing the following properties from type 'D': x, explicitThis, explicitD
    c.explicitThis = d.explicitThis;
    ~~~~~~~~~~~~~~
!!! error TS2322: Type '(this: D, m: number) => number' is not assignable to type '(this: C, m: number) => number'.
    c.explicitVoid = d.explicitD;
    ~~~~~~~~~~~~~~
!!! error TS2322: Type '(this: D, m: number) => number' is not assignable to type '(this: void, m: number) => number'.
!!! error TS2322:   The 'this' types of each signature are incompatible.
!!! error TS2322:     Type 'void' is not assignable to type 'D'.
    c.explicitVoid = d.explicitThis;
    ~~~~~~~~~~~~~~
!!! error TS2322: Type '(this: D, m: number) => number' is not assignable to type '(this: void, m: number) => number'.
!!! error TS2322:   The 'this' types of each signature are incompatible.
!!! error TS2322:     Type 'void' is not assignable to type 'D'.
    
    /// class-based polymorphic assignability (with inheritance!) ///
    
    class Base1 {
        x: number
        public polymorphic(this: this): number { return this.x; }
        explicit(this: Base1): number { return this.x; }
        static explicitStatic(this: typeof Base1): number { return this.x; }
                                                                        ~
!!! error TS2339: Property 'x' does not exist on type 'typeof Base1'.
    }
    class Derived1 extends Base1 {
        y: number
    }
    class Base2 {
        y: number
        polymorphic(this: this): number { return this.y; }
        explicit(this: Base1): number { return this.x; }
    }
    class Derived2 extends Base2 {
        x: number
    }
    
    
    let b1 = new Base1();
    let d1 = new Derived1();
    let b2 = new Base2();
    let d2 = new Derived2();
    
    b1.polymorphic = b2.polymorphic // error, 'this.y' not in Base1: { x }
    ~~~~~~~~~~~~~~
!!! error TS2322: Type '(this: Base2) => number' is not assignable to type '(this: Base1) => number'.
!!! error TS2322:   The 'this' types of each signature are incompatible.
!!! error TS2322:     Property 'y' is missing in type 'Base1' but required in type 'Base2'.
!!! related TS2728 tests/cases/conformance/types/thisType/thisTypeInFunctionsNegative.ts:131:5: 'y' is declared here.
    b1.explicit = b2.polymorphic // error, 'y' not in Base1: { x }
    ~~~~~~~~~~~
!!! error TS2322: Type '(this: Base2) => number' is not assignable to type '(this: Base1) => number'.
!!! error TS2322:   The 'this' types of each signature are incompatible.
!!! error TS2322:     Type 'Base1' is not assignable to type 'Base2'.
    
    d1.explicit = b2.polymorphic // error, 'y' not in Base1: { x }
    ~~~~~~~~~~~
!!! error TS2322: Type '(this: Base2) => number' is not assignable to type '(this: Base1) => number'.
    
    ////// use this-type for construction with new ////
    function VoidThis(this: void) {
    
    }
    let voidThis = new VoidThis();
                   ~~~~~~~~~~~~~~
!!! error TS2679: A function that is called with the 'new' keyword cannot have a 'this' type that is 'void'.
    
    ///// syntax-ish errors /////
    class ThisConstructor {
        constructor(this: ThisConstructor, private n: number) {
                    ~~~~~~~~~~~~~~~~~~~~~
!!! error TS2681: A constructor cannot have a 'this' parameter.
        }
    }
    interface ThisConstructorInterface {
        new(this: ThisConstructor, n: number);
            ~~~~~~~~~~~~~~~~~~~~~
!!! error TS2681: A constructor cannot have a 'this' parameter.
    }
    var thisConstructorType: new (this: number) => number;
                                  ~~~~~~~~~~~~
!!! error TS2681: A constructor cannot have a 'this' parameter.
    function notFirst(a: number, this: C): number { return this.n; }
                                 ~~~~~~~
!!! error TS2680: A 'this' parameter must be the first parameter.
    
    ///// parse errors /////
    function modifiers(async this: C): number { return this.n; }
                             ~~~~
!!! error TS1003: Identifier expected.
                             ~~~~~~~
!!! error TS2680: A 'this' parameter must be the first parameter.
    function restParam(...this: C): number { return this.n; }
                          ~~~~
!!! error TS1003: Identifier expected.
                          ~~~~~~~
!!! error TS2680: A 'this' parameter must be the first parameter.
    function optional(this?: C): number { return this.n; }
                          ~
!!! error TS1005: ',' expected.
    function decorated(@deco() this: C): number { return this.n; }
                               ~~~~
!!! error TS1003: Identifier expected.
                               ~~~~~~~
!!! error TS2680: A 'this' parameter must be the first parameter.
    function initializer(this: C = new C()): number { return this.n; }
                                 ~
!!! error TS1005: ',' expected.
                                   ~~~
!!! error TS1003: Identifier expected.
                                        ~
!!! error TS1005: ',' expected.
                                         ~
!!! error TS1109: Expression expected.
                                          ~
!!! error TS1005: ';' expected.
                                           ~
!!! error TS1128: Declaration or statement expected.
                                             ~~~~~~
!!! error TS2693: 'number' only refers to a type, but is being used as a value here.
                                                    ~
!!! error TS1005: ';' expected.
    
    // can't name parameters 'this' in a lambda.
    c.explicitProperty = (this, m) => m + this.n;
                          ~~~~
!!! error TS2730: An arrow function cannot have a 'this' parameter.
    const f2 = <T>(this: {n: number}, m: number) => m + this.n;
                   ~~~~~~~~~~~~~~~~~
!!! error TS2730: An arrow function cannot have a 'this' parameter.
    const f3 = async (this: {n: number}, m: number) => m + this.n;
                      ~~~~~~~~~~~~~~~~~
!!! error TS2730: An arrow function cannot have a 'this' parameter.
    const f4 = async <T>(this: {n: number}, m: number) => m + this.n;
                         ~~~~~~~~~~~~~~~~~
!!! error TS2730: An arrow function cannot have a 'this' parameter.