Issue when combining yarn workspaces, type-only imports, webpack --watch, fork-ts-checker-webpack-plugin

Type-only imports (import type X, or import X where X is only used as a type) result in incorrect webpack --watch behavior. When files residing in workspace packages are modified, the importing code does not always get recompiled.

Steps to reproduce:

1. Run yarn install && yarn webpack --watch --progress --mode=development

2. Modify type Example1 in packages/pkg1/index.ts. Observe that webpack does not recompile src/index.ts nor display new type errors. ❌

3. Modify function Example2 in packages/pkg2/index.ts. Observe that webpack does recompile src/index.ts and display new type errors (this is not a type-only import). ✅

4. Add "compilerOptions": { "importsNotUsedAsValues": "preserve" } to tsconfig.json. Now, observe that changing pkg1/index.ts does cause webpack to recompile. ✅

   • Change import {Example1} from 'pkg1' to import type {Example1} from 'pkg1' in src/index.ts. Observe that changing pkg1/index.ts again does not result in a recompile. ❌ (This is because "importsNotUsedAsValues": "preserve" does not affect explicit import type imports, which are always removed.)