fix(entry): honor custom root for object entry (#1072)

Author: giaBaoJS

src/features/entry.test.ts

@@ -250,4 +250,53 @@ describe('toObjectEntry', () => {
       'src/utils/helper': path.join(testDir, 'src/utils/helper.ts'),
     })
   })
+
+  test('object entry with custom root', async (context) => {
+    const { testDir } = await writeFixtures(context, {
+      'src/index.ts': '',
+      'src/utils/helper.ts': '',
+    })
+    const root = testDir
+    const [result, resolvedRoot] = await toObjectEntry(
+      { main: 'src/index.ts', helper: 'src/utils/helper.ts' },
+      testDir,
+      root,
+    )
+    expect(resolvedRoot).toBe(root)
+    // Object entry keys are user-provided, so the root must not rename them.
+    expect(result).toEqual({
+      main: 'src/index.ts',
+      helper: 'src/utils/helper.ts',
+    })
+  })
+
+  test('object entry with glob key and custom root', async (context) => {
+    const { testDir } = await writeFixtures(context, {
+      'src/index.ts': '',
+      'src/utils/helper.ts': '',
+    })
+    const root = testDir
+    const [result, resolvedRoot] = await toObjectEntry(
+      { 'lib/*': 'src/**/*.ts' },
+      testDir,
+      root,
+    )
+    expect(resolvedRoot).toBe(root)
+    expect(result).toEqual({
+      'lib/index': path.join(testDir, 'src/index.ts'),
+      'lib/utils/helper': path.join(testDir, 'src/utils/helper.ts'),
+    })
+  })
+
+  test('object entry without custom root', async (context) => {
+    const { testDir } = await writeFixtures(context, {
+      'src/index.ts': '',
+      'src/utils/helper.ts': '',
+    })
+    const [, resolvedRoot] = await toObjectEntry(
+      { main: 'src/index.ts', helper: 'src/utils/helper.ts' },
+      testDir,
+    )
+    expect(resolvedRoot).toBe('src')
+  })
 })

src/features/entry.ts

@@ -50,7 +50,7 @@ export function toObjectEntry(
   }
 
   if (!Array.isArray(entry)) {
-    return resolveObjectEntry(entry, cwd)
+    return resolveObjectEntry(entry, cwd, root)
   }
   return resolveArrayEntry(entry, cwd, root)
 }
@@ -69,6 +69,7 @@ export function isGlobEntry(entry: TsdownInputOption | undefined): boolean {
 async function resolveObjectEntry(
   entries: Record<string, string | string[]>,
   cwd: string,
+  root?: string,
 ): Promise<[entry: Record<string, string>, root: string]> {
   const entry = Object.fromEntries(
     (
@@ -130,8 +131,8 @@ async function resolveObjectEntry(
       )
     ).flat(),
   )
-  const root = lowestCommonAncestor(...Object.values(entry))
-  return [entry, root]
+  const computedRoot = root || lowestCommonAncestor(...Object.values(entry))
+  return [entry, computedRoot]
 }
 
 async function resolveArrayEntry(