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Add support for custom module resolution conditions in tsconfig.json #53213
Description
Suggestion
🔍 Search Terms
package.json exports condition
✅ Viability Checklist
My suggestion meets these guidelines:
- [√] This wouldn't be a breaking change in existing TypeScript/JavaScript code
- [√] This wouldn't change the runtime behavior of existing JavaScript code
- [√] This could be implemented without emitting different JS based on the types of the expressions
- [√] This isn't a runtime feature (e.g. library functionality, non-ECMAScript syntax with JavaScript output, new syntax sugar for JS, etc.)
- [√] This feature would agree with the rest of TypeScript's Design Goals.
⭐ Suggestion
New config in tsconfig.json about custom module resolution conditions: https://nodejs.org/api/packages.html#community-conditions-definitions.
📃 Motivating Example
Sharing same typescript source codes and generating outputs for different targets in monorepo.
💻 Use Cases
My monorepo:
- packages
- my-lib
- src
- dist
- dev
- prod
- package.json
- tsconfig.dev.json
- tsconfig.prod.json
- my-app
- src
- dist
- dev
- prod
- package.json
- tsconfig.dev.json
- tsconfig.prod.json
packages/my-lib/tsconfig.dev.json:
{
"compilerOptions": {
"rootDir": "./src",
"outDir": "./dist/dev",
},
}
packages/my-lib/tsconfig.prod.json:
{
"compilerOptions": {
"rootDir": "./src",
"outDir": "./dist/prod",
},
}
packages/my-lib/package.json:
{
"exports": {
"dev": "./dist/dev/index.d.ts",
"prod": "./dist/prod/index.d.ts",
},
}
packages/my-app/tsconfig.dev.json:
{
"compilerOptions": {
"rootDir": "./src",
"outDir": "./dist/dev",
"module": "commonjs",
"moduleResolution": "node16",
"moduleResolutionConditions": ["dev"], // feature request
},
"references": [
{ "path": "../my-lib/tsconfig.dev.json }
],
}
packages/my-app/tsconfig.prod.json:
{
"compilerOptions": {
"rootDir": "./src",
"outDir": "./dist/prod",
"module": "commonjs",
"moduleResolution": "node16",
"moduleResolutionConditions": ["prod"], // feature request
},
"references": [
{ "path": "../my-lib/tsconfig.prod.json }
],
}
Switch target between "dev" and "prod" may be an unnecessary demand, but switch between something like "server" and "client", or "node" and "dom" may be impossible without this feature.
Activity
pilaoda commentedon Mar 12, 2023
https://webpack.js.org/guides/package-exports/#conditions-custom
Since packages like webpack already support such custom conditions, I think there is no reason that typescript should abandon this feature.
npenin commentedon Apr 4, 2023
Even though it is hard to find in the doc, the feature already exists: https://www.typescriptlang.org/tsconfig#customConditions
pilaoda commentedon Apr 4, 2023
Great job! I guess this issue is created on version 4.9 which does't support this feature. Any way, Thanks!