Array of objects with same fields but mapped to different enum types causes "Error: Debug Failure. False expression".

[markwongsk]

TypeScript Version:

1.8.7

Code

file1.ts:

export enum MyEnum {
    FOO
};

export var object1 = {
    foo: MyEnum.FOO
};

file2.ts:

export enum MyEnum {
    BAR
}

export var object2 = {
    foo: MyEnum.BAR
};

file3.ts

import * as file1 from "./file1";
import * as file2 from "./file2";

let broken = [
    file1.object1,
    file2.object2
];

Run tsc file1.ts file2.ts file3.ts
Expected behavior:
Either compiler emits an error saying that it cannot find a common type for broken, or compilation succeeds.

Actual behavior:

/usr/local/lib/node_modules/typescript/lib/tsc.js:32996
                throw e;
                ^

Error: Debug Failure. False expression: 
    at Object.assert (/usr/local/lib/node_modules/typescript/lib/tsc.js:757:23)
    at reportError (/usr/local/lib/node_modules/typescript/lib/tsc.js:15894:26)
    at enumRelatedTo (/usr/local/lib/node_modules/typescript/lib/tsc.js:16444:29)
    at isRelatedTo (/usr/local/lib/node_modules/typescript/lib/tsc.js:15922:34)
    at propertiesRelatedTo (/usr/local/lib/node_modules/typescript/lib/tsc.js:16256:43)
    at objectTypeRelatedTo (/usr/local/lib/node_modules/typescript/lib/tsc.js:16178:30)
    at isRelatedTo (/usr/local/lib/node_modules/typescript/lib/tsc.js:15991:38)
    at checkTypeRelatedTo (/usr/local/lib/node_modules/typescript/lib/tsc.js:15882:26)
    at checkTypeSubtypeOf (/usr/local/lib/node_modules/typescript/lib/tsc.js:15757:20)
    at isTypeSubtypeOf (/usr/local/lib/node_modules/typescript/lib/tsc.js:15751:20)

Note that casting the array explicitly, eg:

let broken: any[] = [
    file1.object1,
    file2.object2
];

let broken: any = [
    file1.object1,
    file2.object2
];

let broken = [
    file1.object1,
    file2.object2
] as any;

let broken = <any[]>[
    file1.object1,
    file2.object2
];

all fail, but casting either object1 or object2 to any would make compilation succeed. For example,

let broken = [
    file1.object1 as any,
    file2.object2
];

I'm guessing this is because the compiler does a subtype checking after it figures out the array type (which it fails to).

[mhegazy]

@markwongsk can you give typescript@next a try tomorrow and let us know if you are still running into issue?

[markwongsk]

Will do. Thanks!