tsconfig paths not resolving in imported package

[IlyaSemenov]

Bug description

I have a monorepo with two packages a and b. I run a script in package a which imports a module from package b. The module in package b imports a submodule from package b using tsconfig paths.

I expect the script to run normally.

Instead, it crashes:

❯ p tsx test.ts 
Error: Cannot find module '@/lib'
Require stack:
- /Users/semenov/tmp/tsx-monorepo-alias/packages/b/index.ts
- /Users/semenov/tmp/tsx-monorepo-alias/packages/a/test.ts
    at Function.Module._resolveFilename (node:internal/modules/cjs/loader:933:15)
    at Function.u.default._resolveFilename (/Users/semenov/tmp/tsx-monorepo-alias/node_modules/.pnpm/@[email protected]/node_modules/@esbuild-kit/cjs-loader/dist/index.js:1:1486)
    at Function.Module._load (node:internal/modules/cjs/loader:778:27)
    at Module.require (node:internal/modules/cjs/loader:1005:19)
    at require (node:internal/modules/cjs/helpers:102:18)
    at Object.<anonymous> (/Users/semenov/tmp/tsx-monorepo-alias/packages/b/index.ts:1:8)
    at Module._compile (node:internal/modules/cjs/loader:1105:14)
    at Object.v (/Users/semenov/tmp/tsx-monorepo-alias/node_modules/.pnpm/@[email protected]/node_modules/@esbuild-kit/cjs-loader/dist/index.js:1:933)
    at Module.load (node:internal/modules/cjs/loader:981:32)
    at Function.Module._load (node:internal/modules/cjs/loader:822:12) {
  code: 'MODULE_NOT_FOUND',
  requireStack: [
    '/Users/semenov/tmp/tsx-monorepo-alias/packages/b/index.ts',
    '/Users/semenov/tmp/tsx-monorepo-alias/packages/a/test.ts'
  ]
}

Reproduction

https://github.com/IlyaSemenov/tsx-monorepo-import-reproduction includes step by step reproduction.

By the way, if you run pnpm add esbuild-runner and run the script with pnpm esr test.ts, it will work! (esbuild-runner is unfortunately abandoned and has other issues)

Environment

System:
    OS: macOS 12.5
    CPU: (8) arm64 Apple M1
    Memory: 74.92 MB / 16.00 GB
    Shell: 5.8.1 - /bin/zsh
  Binaries:
    Node: 16.15.0 - ~/.nodenv/versions/16.15.0/bin/node
    Yarn: 1.22.19 - ~/.nodenv/versions/16.15.0/bin/yarn
    npm: 8.5.5 - ~/.nodenv/versions/16.15.0/bin/npm

tsx is version 3.8.1

Can you contribute a fix?

• I’m interested in opening a pull request for this issue.

[privatenumber]

This is expected behavior.

A TypeScript compilation—which is happening at runtime in this case—, cannot load more than one tsconfig.json at once. I imagine esr is looking up a tsconfig.json for each file, but that's expensive and also not correct behavior.

I verified that tsx's behavior is consistent with ts-node.

[IlyaSemenov]

@privatenumber But this is not consistent with esbuild itself! In the reproduction repo:

❯ p esbuild test.ts --bundle > test.js

❯ cat test.js
"use strict";
(() => {
  // ../b/lib.ts
  console.log("imported lib");
})();

❯ node test.js
imported lib

So it's possible to build a production build with these aliases but not run it in dev mode with tsx? Please reconsider your decision.

[IlyaSemenov]

@privatenumber thoughts?

[privatenumber]

Curious how esbuild works if setting a different tsconfig path?

https://esbuild.github.io/api/#tsconfig

[IlyaSemenov]

@privatenumber esbuild supports multiple tsconfig.json from referenced folders - same as I would expect from tsx.

This is explicitly stated by Evan, e.g.:

• should follow tsconfig compilerOptions target when didn't pass target evanw/esbuild#277 (comment): "different directories can take their settings from different tsconfig.json files with esbuild"
• https://pullanswer.com/questions/esbuild-resolves-modules-by-using-the-typescript-modulesuffixes-per-package-instead-of-per-bundle#711300: "This is why esbuild supports multiple tsconfig.json files: because each folder with a tsconfig.json file in it is conceptually a thing that you would traditionally run tsc in for each one before bundling."

[privatenumber]

How does it handle custom tsconfig.json paths via the tsconfig CLI flag for multiple projects?

e.g. If project A uses tsconfig.a.json and its dependency project B uses tsconfig.b.json, how is it configured?

[IlyaSemenov]

I'm not following how is that related to the case. From what I've quickly gathered, there's no esbuild API option to provide different custom named tsconfig's for different projects. Why would that matter?

[privatenumber]

In case the uncompiled dependency project has a custom tsconfig (eg. with paths configured).

I'm going to lock this thread in favor of #96 since this one is already closed.