fix: rootDir calculation should ignore declaration files

packages/plugin-dts/src/dts.ts

@@ -133,9 +133,17 @@ export async function generateDts(data: DtsGenOptions): Promise<void> {
     throw new Error();
   }
   const { options: rawCompilerOptions, fileNames } = loadTsconfig(configPath);
+
+  // The longest common path of all non-declaration input files.
+  // If composite is set, the default is instead the directory containing the tsconfig.json file.
+  // see https://www.typescriptlang.org/tsconfig/#rootDir
   const rootDir =
     rawCompilerOptions.rootDir ??
-    (await calcLongestCommonPath(fileNames)) ??
+    (rawCompilerOptions.composite
+      ? dirname(configPath)
+      : await calcLongestCommonPath(
+          fileNames.filter((fileName) => !/\.d\.(ts|mts|cts)$/.test(fileName)),
+        )) ??
     dirname(configPath);
 
   const outDir = distPath

scripts/dictionary.txt

@@ -93,6 +93,7 @@ pxtorem
 quxx
 rebranded
 rolldown
+rootdir
 rsbuild
 rsdoctor
 rsfamily

tests/integration/dts/__snapshots__/index.test.ts.snap

@@ -60,3 +60,44 @@ export { }
 ",
 }
 `;
+
+exports[`dts when bundle: true > rootdir calculation should ignore declaration files 3`] = `
+{
+  "cjs": "export declare const num1 = 1;
+
+export declare const num2 = 2;
+
+export declare const num3 = 3;
+
+export declare const numSum: number;
+
+export declare const str1 = "str1";
+
+export declare const str2 = "str2";
+
+export declare const str3 = "str3";
+
+export declare const strSum: string;
+
+export { }
+",
+  "esm": "export declare const num1 = 1;
+
+export declare const num2 = 2;
+
+export declare const num3 = 3;
+
+export declare const numSum: number;
+
+export declare const str1 = "str1";
+
+export declare const str2 = "str2";
+
+export declare const str3 = "str3";
+
+export declare const strSum: string;
+
+export { }
+",
+}
+`;

tests/integration/dts/bundle/rootdir/package.json

@@ -0,0 +1,9 @@
+{
+  "name": "dts-bundle-rootdir-test",
+  "version": "1.0.0",
+  "private": true,
+  "type": "module",
+  "devDependencies": {
+    "@types/chromecast-caf-sender": "^1.0.10"
+  }
+}

tests/integration/dts/bundle/rootdir/rslib.config.ts

@@ -0,0 +1,22 @@
+import { defineConfig } from '@rslib/core';
+import { generateBundleCjsConfig, generateBundleEsmConfig } from 'test-helper';
+
+export default defineConfig({
+  lib: [
+    generateBundleEsmConfig({
+      dts: {
+        bundle: true,
+      },
+    }),
+    generateBundleCjsConfig({
+      dts: {
+        bundle: true,
+      },
+    }),
+  ],
+  source: {
+    entry: {
+      index: '../__fixtures__/src/index.ts',
+    },
+  },
+});

tests/integration/dts/bundle/rootdir/tsconfig.json

@@ -0,0 +1,4 @@
+{
+  "extends": "@rslib/tsconfig/base",
+  "include": ["../__fixtures__/src", "node_modules/@types"]
+}

tests/integration/dts/index.test.ts

@@ -221,6 +221,28 @@ describe('dts when bundle: true', () => {
     `,
     );
   });
+
+  test('rootdir calculation should ignore declaration files', async () => {
+    const fixturePath = join(__dirname, 'bundle', 'rootdir');
+    const { files, entries } = await buildAndGetResults({
+      fixturePath,
+      type: 'dts',
+    });
+
+    expect(files.esm).toMatchInlineSnapshot(`
+      [
+        "<ROOT>/tests/integration/dts/bundle/rootdir/dist/esm/index.d.ts",
+      ]
+    `);
+
+    expect(files.cjs).toMatchInlineSnapshot(`
+      [
+        "<ROOT>/tests/integration/dts/bundle/rootdir/dist/cjs/index.d.ts",
+      ]
+    `);
+
+    expect(entries).toMatchSnapshot();
+  });
 });
 
 describe('dts when build: true', () => {