tests/cases/compiler/assignmentCompatBug2.ts(1,27): error TS2322: Type '{ a: number; }' is not assignable to type '{ b: number; }'. Object literal may only specify known properties, and 'a' does not exist in type '{ b: number; }'. tests/cases/compiler/assignmentCompatBug2.ts(3,8): error TS2322: Type '{ a: number; }' is not assignable to type '{ b: number; }'. Object literal may only specify known properties, and 'a' does not exist in type '{ b: number; }'. tests/cases/compiler/assignmentCompatBug2.ts(5,13): error TS2322: Type '{ b: number; a: number; }' is not assignable to type '{ b: number; }'. Object literal may only specify known properties, and 'a' does not exist in type '{ b: number; }'. tests/cases/compiler/assignmentCompatBug2.ts(15,1): error TS2322: Type '{ f: (n: number) => number; g: (s: string) => number; }' is not assignable to type '{ f(n: number): number; g(s: string): number; m: number; n?: number; k?(a: any): any; }'. Property 'm' is missing in type '{ f: (n: number) => number; g: (s: string) => number; }'. tests/cases/compiler/assignmentCompatBug2.ts(20,1): error TS2322: Type '{ f: (n: number) => number; m: number; }' is not assignable to type '{ f(n: number): number; g(s: string): number; m: number; n?: number; k?(a: any): any; }'. Property 'g' is missing in type '{ f: (n: number) => number; m: number; }'. tests/cases/compiler/assignmentCompatBug2.ts(33,1): error TS2322: Type '{ f: (n: number) => number; g: (s: string) => number; n: number; k: (a: any) => any; }' is not assignable to type '{ f(n: number): number; g(s: string): number; m: number; n?: number; k?(a: any): any; }'. Property 'm' is missing in type '{ f: (n: number) => number; g: (s: string) => number; n: number; k: (a: any) => any; }'. ==== tests/cases/compiler/assignmentCompatBug2.ts (6 errors) ==== var b2: { b: number;} = { a: 0 }; // error ~~~~ !!! error TS2322: Type '{ a: number; }' is not assignable to type '{ b: number; }'. !!! error TS2322: Object literal may only specify known properties, and 'a' does not exist in type '{ b: number; }'. b2 = { a: 0 }; // error ~~~~ !!! error TS2322: Type '{ a: number; }' is not assignable to type '{ b: number; }'. !!! error TS2322: Object literal may only specify known properties, and 'a' does not exist in type '{ b: number; }'. b2 = {b: 0, a: 0 }; ~~~~ !!! error TS2322: Type '{ b: number; a: number; }' is not assignable to type '{ b: number; }'. !!! error TS2322: Object literal may only specify known properties, and 'a' does not exist in type '{ b: number; }'. var b3: { f(n: number): number; g(s: string): number; m: number; n?: number; k?(a: any): any; }; b3 = { f: (n) => { return 0; }, g: (s) => { return 0; }, m: 0, }; // ok b3 = { ~~ !!! error TS2322: Type '{ f: (n: number) => number; g: (s: string) => number; }' is not assignable to type '{ f(n: number): number; g(s: string): number; m: number; n?: number; k?(a: any): any; }'. !!! error TS2322: Property 'm' is missing in type '{ f: (n: number) => number; g: (s: string) => number; }'. f: (n) => { return 0; }, g: (s) => { return 0; }, }; // error b3 = { ~~ !!! error TS2322: Type '{ f: (n: number) => number; m: number; }' is not assignable to type '{ f(n: number): number; g(s: string): number; m: number; n?: number; k?(a: any): any; }'. !!! error TS2322: Property 'g' is missing in type '{ f: (n: number) => number; m: number; }'. f: (n) => { return 0; }, m: 0, }; // error b3 = { f: (n) => { return 0; }, g: (s) => { return 0; }, m: 0, n: 0, k: (a) =>{ return null; }, }; // ok b3 = { ~~ !!! error TS2322: Type '{ f: (n: number) => number; g: (s: string) => number; n: number; k: (a: any) => any; }' is not assignable to type '{ f(n: number): number; g(s: string): number; m: number; n?: number; k?(a: any): any; }'. !!! error TS2322: Property 'm' is missing in type '{ f: (n: number) => number; g: (s: string) => number; n: number; k: (a: any) => any; }'. f: (n) => { return 0; }, g: (s) => { return 0; }, n: 0, k: (a) =>{ return null; }, }; // error