Webpack watch missing changed files

[KnisterPeter]

Expected Behaviour

Detect all changed files used in a compilation

Actual Behaviour

Some files are missing in some cases

Steps to Reproduce the Problem

https://github.com/KnisterPeter/webpack-multi-app-test

Run npm run watch and change src/core/plugin.ts.
It is expected that src/sub/index.tsx fails afterswards.

Location of a Minimal Repository that Demonstrates the Issue.

https://github.com/KnisterPeter/webpack-multi-app-test

The problem is within the watch-run. Changed files are filtered here. Maybe its deeper and webpack does not set correct timestamps.

https://github.com/TypeStrong/ts-loader/blob/master/src/watch-run.ts#L25

[johnnyreilly]

Thanks for the minimal repro repo - that's always appreciated. I suspect the issue is that the file in question is interfaces only; i.e. it produces no JS output which means file changes result in no changes to the JS output. As far as webpack is concerned, there wasn't any output before; there isn't now either.

There's not an immediately obvious solution to this. However, I'm hopeful that when the new watch API changes get merged (#685) this may resolve the issue.

[KnisterPeter]

Right now there is at least the defintion file updated. Wouldn't it this idea be possible:

1. Filter the list of files as it is done now but exclude .d.ts files.
2. Always handle .d.ts files as if they where touched.

[KnisterPeter]

As well, right now it does not even help to touch those files and there is no hook into the loader to trigger it manually (I know what was updated and when).

[KnisterPeter]

To give some more info here, this is the content of the times object in watch-run.ts:

{
  '/x/webpack-test/src/sub/app.tsx': 1513681246518,
  '/x/webpack-test/src/sub/index.tsx': 1513691257828,
  '/x/webpack-test/src/sub/package.json': 1513679868805,
  '/x/webpack-test/src/sub/tsconfig.json': 1513679868805,
  '/x/webpack-test/dist/core/index.d.ts': 1,
  '/x/webpack-test/dist/core/plugin.d.ts': 1,
  '/x/webpack-test/node_modules/@types/node/index.d.ts': 1,
  '/x/webpack-test/node_modules/@types/node/inspector.d.ts': 1,
  '/x/webpack-test/node_modules/@types/react-dom/index.d.ts': 1,
  '/x/webpack-test/node_modules/@types/react/global.d.ts': 1,
  '/x/webpack-test/node_modules/@types/react/index.d.ts': 1,
  '/x/webpack-test/node_modules/typescript/lib/lib.d.ts': 1
}

Everything with a timestamp of 1 and not 'living' in node_modules could be seen as updated. These files are all part of the current compilation and therefore part of the ts Program.

[johnnyreilly]

I'm open to PRs that fix the issue - I'd be happy to advise along the way

[ZSkycat]

I have encountered the same problem. The reason for this problem is not just a pure types file, but a ts file that is not actually used. That is, only type or interface is imported.

This problem can be solved by import './type';

Don't worry. The webpack production mode can removes empty modules and tree shaking. This won't have extra code being packaged. 😄

my case

type.ts

export interface InterfaceA {
    a1: number;
    a2: string;
}

export function test() {
    console.log('test');
}

index.ts

import { InterfaceA } from './type';
// import './type';

export function app(value: InterfaceA) {
    console.log(value.a1.toFixed(0));
    console.log(value.a2.trim());
}