[heft] Typescript plugin no longer calls path.resolve for configFilePath in compiler options, causing incorrect output paths

[barryhagan]

Summary

After upgrading heft to 0.51.0, our projects failed to build because the typescript compiler was no longer emitting files into the specified outDir location. Instead, the files were next to the sources as if outDir was not set in tsconfig.json.

Repro steps

Run heft build with these settings in tsconfig.json:

{
    "compilerOptions": {
        "composite": true,
        "outDir": "lib",
        "types": ["node", "jest"]
    },
    "include": ["./src/**/*", "./__tests__/**/*"],
    "exclude": [
        "./lib",
        "node_modules"
    ]
}

typescript.json in the rig should not have a project value set (defaults to ./tsconfig.json).

Expected result:

Compiled .js files will be in a folder structure under ./lib.

Actual result:

The tsconfig.tsbuildinfo file is under ./lib, but the compiled .js and .d.ts files remain next to the sources.

Details

As of heft 0.51.0 and heft-typescript-plugin 0.1.0, the configFilePath supplied to the typescript compiler program is no longer resolved, and this subtle difference changes where the compiler outputs files.

0.50.x versions with the built-in plugin would resolve the path:

https://github.com/microsoft/rushstack/blob/%40rushstack/heft_v0.50.7/apps/heft/src/plugins/TypeScriptPlugin/TypeScriptPlugin.ts#L209

producing a compiler option: "configFilePath”:”/path-to-project/tsconfig.json"

The new plugin simply concats the project with the build folder:

https://github.com/barryhagan/rushstack/blob/main/heft-plugins/heft-typescript-plugin/src/TypeScriptPlugin.ts#L176

producing a compiler option: "configFilePath”:”/path-to-project/./tsconfig.json"

This is might actually be a bug in the typescript compiler as the extra './' path segment should not do this, but it causes the compiler to not use the configured outDir value.

A simple workaround is to set project in typescript.json to be tsconfig.json instead of defaulting to ./tsconfig.json so the string concat works, but it would be nice to restore the path.resolve to avoid this problem.

Standard questions

Please answer these questions to help us investigate your issue more quickly:

Question	Answer
@rushstack/heft version?	0.51.0
Operating system?	Mac
Would you consider contributing a PR?	Yes
Node.js version (node -v)?	18.15.0