Module resolution: self-references file are resolved after 5.7

[FoundTheWOUT]

Demo Repo

https://github.com/FoundTheWOUT/tsc-resolved-non-inclued-file

Which of the following problems are you reporting?

Something else more complicated which I'll explain in more detail

Demonstrate the defect described above with a code sample.

import { name } from "@scope/lib/a"; // should not error

Run tsc --showConfig and paste its output here

{
    "compilerOptions": {
        "rootDir": "./b",
        "outDir": "./dist/b",
        "types": [],
        "noEmit": true,
        "target": "esnext",
        "module": "esnext",
        "moduleResolution": "bundler",
        "resolveJsonModule": true,
        "skipLibCheck": true,
        "allowSyntheticDefaultImports": true,
        "resolvePackageJsonExports": true,
        "resolvePackageJsonImports": true,
        "useDefineForClassFields": true
    },
    "files": [
        "./b/index.ts"
    ],
    "include": [
        "./b/**/*.ts"
    ],
    "exclude": [
        "dist"
    ]
}

Run tsc --traceResolution and paste its output here

sry, too long and file upload is not allowed

Paste the package.json of the importing module, if it exists

/

Paste the package.json of the target module, if it exists

/

Any other comments can go here

File 'x' is not under 'rootDir' 'y'. 'rootDir' is expected to contain all source files.

Our project uses self-references (importing the package itself), but we encountered errors after upgrading TypeScript to 5.7+. We are splitting each feature into an independent folder and bundling/typing them separately. Using self-references makes it easier to configure externals for the bundler.

Project structure

dist/
|- a/
|-- index.d.ts
|-- index.js
|- b/
|-- src/
|--- utils.d.ts
|-- index.d.ts <- we structure declaration file like that
|-- index.js
a/
|- index.ts
b/
|- src/
|-- utils.ts
|- index.ts
tsconfig.b.tmp.json <- generate at build time

// dist/b/index.js
// this is not emit by tsc, we use rollup and set my-pack to external, we use tsc to generate declaration file
import a from "my-pack/a";

// tsconfig.b.tmp.json
{
    "compilerOptions": {
        "rootDir": "./b",
        "outDir": "./dist/b",
        "noEmit": false,
        "target": "esnext",
        "module": "esnext",
        "moduleResolution": "bundler",
    },
    "include": [
        "./b/**/*.ts"
    ],
}

// package.json
{
  "name": "my-pack",
  "type": "module",
  "exports": {
    "./*": {
      "types": "./dist/*/index.d.ts",
      "import": "./dist/*/index.js"
    }
  }
}

[RyanCavanaugh]

This is a correct error. The resolution resolved to a .ts file, not a .d.ts file. You need to have built a first in this scenario, and/or used a project reference.