Const enum by-const-enum-reference value not elided in incremental build

[jkieboom]

TypeScript Version: 2.7.0-dev.20171109

Code

// file1.ts
export const enum E1 {
  V = 1
}

// file2.ts
import { E1 } from "./file1";

export const enum E2 {
  V = E1.V
}

// file3.ts
import { E2 } from "./file2";

const v: E2 = E2.V;

Expected behavior:

The value of v in file3 when compiled should always be 1.

Actual behavior:

When running tsc in watch mode, when file3 changes and is recompiled, the resulting javascript now contains v = E2.V instead of the constant 1, and fails at runtime with an unknown reference.

[mhegazy]

@sheetalkamat can you take a look.. let's try to get a fix in 2.6.2 for this

[mhegazy]

@jkieboom please give tomorrow's typescript@next a try and let us know if you are still running into issues.

[jkieboom]

I can confirm that typescript@next fixes the issue, thanks a lot for the very quick response!