fix(create): normalize add-to-app output paths on Windows

Normalize generated and deleted output file paths to project-relative keys before compare/write/delete, preventing duplicated path segments when Windows drive letters are missing.

Fixes #329

Author: tannerlinsley

.changeset/ten-wombats-learn.md

@@ -0,0 +1,5 @@
+---
+'@tanstack/create': patch
+---
+
+Fix `tanstack add` on Windows when generated output paths lose the drive letter, preventing duplicated project paths from being written.

packages/create/src/add-to-app.ts

@@ -88,6 +88,41 @@ export async function writeFiles(
   },
   forced: boolean,
 ) {
+  const toRelativePath = (filePath: string) => {
+    const normalizedFilePath = filePath.replace(/\\/g, '/')
+    const normalizedCwd = cwd.replace(/\\/g, '/')
+    const cwdWithoutDrive = normalizedCwd.replace(/^[a-zA-Z]:/, '')
+    const cwdWithoutDriveNoLeading = cwdWithoutDrive.replace(/^\/+/, '')
+
+    if (normalizedFilePath === normalizedCwd) {
+      return ''
+    }
+    if (normalizedFilePath.startsWith(`${normalizedCwd}/`)) {
+      return normalizedFilePath.slice(normalizedCwd.length + 1)
+    }
+    if (normalizedFilePath === cwdWithoutDrive) {
+      return ''
+    }
+    if (normalizedFilePath.startsWith(`${cwdWithoutDrive}/`)) {
+      return normalizedFilePath.slice(cwdWithoutDrive.length + 1)
+    }
+    if (normalizedFilePath === cwdWithoutDriveNoLeading) {
+      return ''
+    }
+    if (normalizedFilePath.startsWith(`${cwdWithoutDriveNoLeading}/`)) {
+      return normalizedFilePath.slice(cwdWithoutDriveNoLeading.length + 1)
+    }
+
+    return normalizedFilePath.replace(/^\/+/, '')
+  }
+
+  const relativeOutputFiles = Object.keys(output.files).reduce<
+    Record<string, string>
+  >((acc, filePath) => {
+    acc[toRelativePath(filePath)] = output.files[filePath]
+    return acc
+  }, {})
+
   const currentFiles = await recursivelyGatherFilesFromEnvironment(
     environment,
     cwd,
@@ -96,10 +131,9 @@ export async function writeFiles(
 
   const overwrittenFiles: Array<string> = []
   const changedFiles: Array<string> = []
-  for (const file of Object.keys(output.files)) {
-    const relativeFile = file.replace(cwd, '')
+  for (const relativeFile of Object.keys(relativeOutputFiles)) {
     if (currentFiles[relativeFile]) {
-      if (currentFiles[relativeFile] !== output.files[file]) {
+      if (currentFiles[relativeFile] !== relativeOutputFiles[relativeFile]) {
         overwrittenFiles.push(relativeFile)
       }
     } else {
@@ -118,9 +152,10 @@ export async function writeFiles(
     }
   }
 
-  for (const file of output.deletedFiles) {
-    if (environment.exists(resolve(cwd, file))) {
-      await environment.deleteFile(resolve(cwd, file))
+  for (const filePath of output.deletedFiles) {
+    const relativeFilePath = toRelativePath(filePath)
+    if (environment.exists(resolve(cwd, relativeFilePath))) {
+      await environment.deleteFile(resolve(cwd, relativeFilePath))
     }
   }
 
@@ -132,7 +167,7 @@ export async function writeFiles(
 
   for (const file of [...changedFiles, ...overwrittenFiles]) {
     const fName = basename(file)
-    const contents = output.files[file]
+    const contents = relativeOutputFiles[file]
     if (fName === 'package.json') {
       const currentJson = JSON.parse(
         await environment.readFile(resolve(cwd, file)),

packages/create/tests/add-to-app.test.ts

@@ -297,6 +297,43 @@ describe('writeFiles', () => {
     environment.finishRun()
     expect(output.deletedFiles).toEqual(['bloop.txt'])
   })
+
+  it('should normalize windows-style output paths before writing', async () => {
+    const writePaths: Array<string> = []
+    const environment = {
+      readdir: async () => [],
+      isDirectory: () => false,
+      readFile: async () => '',
+      exists: () => false,
+      deleteFile: async () => {},
+      writeFileBase64: async () => {},
+      writeFile: async (path: string) => {
+        writePaths.push(path)
+      },
+      startStep: () => {},
+      finishStep: () => {},
+      warn: () => {},
+      confirm: async () => true,
+    } as any
+
+    await writeFiles(
+      environment,
+      'C:\\Users\\marv\\workspace\\fenbi-tanstack',
+      {
+        files: {
+          'Users/marv/workspace/fenbi-tanstack/src/components.json': '{}',
+        },
+        deletedFiles: [],
+      },
+      true,
+    )
+
+    expect(writePaths).toHaveLength(1)
+    expect(writePaths[0]).toMatch(/components\.json$/)
+    expect(writePaths[0]).not.toMatch(
+      /Users[\\/]marv[\\/]workspace[\\/]fenbi-tanstack[\\/]Users[\\/]marv[\\/]workspace[\\/]fenbi-tanstack/,
+    )
+  })
 })
 
 describe('runNewCommands', () => {