forceConsistentCasingInFileNames error message doesn't contain enough information

TypeScript Version:

1.9.0-dev.20160301

Code

a.ts

import B from './b';
console.log(B);

B.ts (note the casing here)

export default function B() {
}

Expected behavior: a.ts is never referred in the the error so it is impossible to know which file and line number is actually trying to import it.

Actual behavior:

tsc a.ts B.ts --forceConsistentCasingInFileNames
error TS1149: File name 'B.ts' differs from already included file name 'C:/dev/sample/a/b.ts' only in casing

Doesn’t work with --pretty flag enabled too.

[nickzelei]

I’ve been able to accurately reproduce this bug (in a single project) by using forceConsistentCasingInFileNames set to true and using the extends keyword. By removing the extends, the bug goes away. However, I’m not always seeing this in every project that utilizes this schema. I have randomly hit this bug.

[bitjson]

@Delagen – not sure, but maybe this is the issue you were facing? #16875

It happens reliably when using the extends property in tsconfig.json.