[dev] Fix missing types from node_modules with at-loader on Windows

[reiv]

Changes proposed in this pull request:

This PR fixes a bug that affects at-loader on Windows: typings from node_modules aren't loaded automatically as they are in other environments, resulting in many errors during compilation, primarily when running unit tests. For example, running yarn test in the core package produces 836 errors, because the namespace for Mocha isn't loaded:

ERROR in [at-loader] ./test/alert/alertTests.tsx:15:1
    TS2304: Cannot find name 'describe'.

ERROR in [at-loader] ./test/alert/alertTests.tsx:16:5
    TS2304: Cannot find name 'it'.

...

(Note that tsc still emits correct code, but the type-checking process fails).

The fix is to explicitly instruct tsc to look in node_modules/@types for type declarations, which is something it should already be doing by default.

[reiv]

Fix missing types with at-loader on Windows

Preview: documentation | landing | table

[giladgray]

ok cool this is nice. is there an issue on at-loader that we can reference?

[reiv]

@giladgray not that I know of. I only found this one #2356 (comment) from angular-starter, where I got the fix from.

[giladgray]

@reiv i think you pasted the wrong link above?

[reiv]

@giladgray PatrickJS/PatrickJS-starter#1371

[giladgray]

@reiv thanks for the link. before merging this, would you mind trying one thing? upgrade awesome-typescript-loader to at least v4.0 for webpack 3 support (https://github.com/s-panferov/awesome-typescript-loader/releases). wondering if this bug has already been fixed?

[reiv]

@giladgray I just gave that a try.

λ yarn list --pattern awesome-typescript-loader
yarn list v1.5.1
└─ awesome-typescript-loader@4.0.1

It didn't fix the issue and now a lot more type definitions can't be found, including node_modules/typescript/lib/lib.*.d.ts and even these globals:

ERROR in [at-loader] TS2318: Cannot find global type 'Array'.
ERROR in [at-loader] TS2318: Cannot find global type 'Boolean'.
ERROR in [at-loader] TS2318: Cannot find global type 'Function'.
ERROR in [at-loader] TS2318: Cannot find global type 'IArguments'.
ERROR in [at-loader] TS2318: Cannot find global type 'Number'.
ERROR in [at-loader] TS2318: Cannot find global type 'Object'.
ERROR in [at-loader] TS2318: Cannot find global type 'RegExp'.
ERROR in [at-loader] TS2318: Cannot find global type 'String'.

It's really quite befuddling.

[giladgray]

@reiv yuck. alright let's merge this!