[Bug] Couldn't find package "tslib" error in a nested project structure

[mcmxcdev]

🐛 Bug report

Description

I am working on a frontend that had the expected structure with tsconfig.json at the root of the project, no error was reported.

Now the frontend was integrated as git submodule within a project with a nested folder structure and I always get the error:

Couldn't find package "tslib".
(typescript-config/import-helpers)

This error pops up even though tslib is installed (v2.0.3) and importHelpers: true is enabled in the tsconfig.json

Environment

• hint version: 1.5.9 (VSCode)
• Node.js version: v14.12.0
• OS: Ubuntu

[antross]

Thanks for reporting @mhatvan!

You mentioned tslib is installed. Is it part of the top-level project or part of the project being loaded as a submodule?

I ask because when I just took another look at the implementation for this hint it looks like it currently only checks the top-level node_modules for tslib which may be the source of the bug:

hint/packages/hint-typescript-config/src/import-helpers.ts

Line 36 in accf822

const pathToTslib = path.join(process.cwd(), 'node_modules', 'tslib');

If so, a fix here likely requires updating the hint to scope the check to opened/included tsconfig.json files. Then it can look for tslib relative to the location of the file as opposed to only at the top-level.

[mcmxcdev]

It is part of the project being loaded as a sub module, so the checking for tslib can definitely be improved to also include subdirectories.

[antross]

@mhatvan would you be interested in putting together a PR for this fix?

Looks like the hint is already triggered after parsing a tsconfig.json so we just need to update the logic to search for tslib relative to the path of the tsconfig.json we just parsed instead of the current working directory. I bet require.resolve with the paths option could do the trick.

[mcmxcdev]

Sure thing, will provide a PR soonish ;)

[mcmxcdev]

@antross After taking an initial look, I am wondering how I can receive the current full path where the tsconfig.json was found through webhint in import-helpers.ts ?

Then this would work: path.dirname(require.resolve("tslib", {paths: ["<path-to-tsconfig.json>"] }))

[antross]

@mhatvan thanks for taking a look!

I think we already have the path to the tsconfig.json as the resource string pulled off the event that triggered the validation:

hint/packages/hint-typescript-config/src/import-helpers.ts

Line 34 in 461a19b

const { resource } = evt;

Does that help?

[mcmxcdev]

Yep, that's it! I got confused because it is not an absolute path but is prefixed by file:///, but works nonetheless!