Bug Report

🔎 Search Terms

import mappings, nodenext, node16, import extensions placed wrong

🕗 Version & Regression Information

• This is the behavior in every version I tried, and I reviewed the FAQ

⏯ Playground Repository Link

Repository where the issue can be seen: https://github.com/vladfrangu/typescript-import-mapping-issue

💻 Code

package.json

{
	"type": "module",
	"scripts": {
		"build": "tsc"
	},
	"devDependencies": {
		"@sapphire/ts-config": "^3.3.4",
		"@types/node": "^17.0.35",
		"typescript": "^4.7.2"
	},
	"imports": {
		"#internals/*": "./dist/internals/*.js"
	}
}

tsconfig.json

{
	"extends": "@sapphire/ts-config",
	"compilerOptions": {
		"target": "ESNext",
		"module": "Node16",
		"moduleResolution": "Node16",
		"rootDir": "./src",
		"outDir": "./dist",
		"paths": {
			"#internals/*": ["./src/internals/*.ts"]
		}
	},
	"include": ["src", "src/**/*.d.ts"]
}

src/internals/example.ts

export function helloWorld() {
	console.log('Hello world!');
}

src/index.ts

// Attempt to import this method with your editor with the "typescript.preferences.importModuleSpecifierEnding" set to "auto"
// Then try the same autoimport with the "typescript.preferences.importModuleSpecifierEnding" set to "index"
helloWorld();

🙁 Actual behavior

Given a package.json with import mappings, attempting to import a file defined in the mapping while typescript.preferences.importModuleSpecifierEnding is set to "auto" will cause the extension to be appended to the import, which in turn immediately causes TypeScript to report a Cannot find module '#internals/example.js' or its corresponding type declarations..

Setting typescript.preferences.importModuleSpecifierEnding to "index" works but it will have side effects for relative imports, which is not ideal.

🙂 Expected behavior

TypeScript should only append the extension to imports that are relative, and not from imports seen from import mapping/paths. (maybe this also ties into #48120 but I am not sure if they're separate issues)