Preserve local changes option

README.md

@@ -96,6 +96,12 @@ Please refer to the [release page](https://github.com/actions/checkout/releases/
     # Default: true
     clean: ''
 
+    # Whether to preserve local changes during checkout. If true, tries to preserve
+    # local files that are not tracked by Git. By default, all files will be
+    # overwritten.
+    # Default: false
+    preserve-local-changes: ''
+
     # Partially clone against a given filter. Overrides sparse-checkout if set.
     # Default: null
     filter: ''
@@ -332,6 +338,21 @@ jobs:
 
 *NOTE:* The user email is `{user.id}+{user.login}@users.noreply.github.com`. See users API: https://api.github.com/users/github-actions%5Bbot%5D
 
+## Preserve local changes during checkout
+
+```yaml
+steps:
+  - name: Create file before checkout
+    shell: pwsh
+    run: New-Item -Path . -Name "example.txt" -ItemType "File"
+
+  - name: Checkout with preserving local changes
+    uses: actions/checkout@v5
+    with:
+      clean: false
+      preserve-local-changes: true
+```
+
 # Recommended permissions
 
 When using the `checkout` action in your GitHub Actions workflow, it is recommended to set the following `GITHUB_TOKEN` permissions to ensure proper functionality, unless alternative auth is provided via the `token` or `ssh-key` inputs:

action.yml

@@ -56,7 +56,10 @@ inputs:
     description: 'Relative path under $GITHUB_WORKSPACE to place the repository'
   clean:
     description: 'Whether to execute `git clean -ffdx && git reset --hard HEAD` before fetching'
-    default: true
+    default: 'true'
+  preserve-local-changes:
+    description: 'Whether to preserve local changes during checkout. If true, tries to preserve local files that are not tracked by Git. By default, all files will be overwritten.'
+    default: 'false'
   filter:
     description: >
       Partially clone against a given filter.

dist/index.js

@@ -609,9 +609,17 @@ class GitCommandManager {
             yield fs.promises.appendFile(sparseCheckoutPath, `\n${sparseCheckout.join('\n')}\n`);
         });
     }
-    checkout(ref, startPoint) {
-        return __awaiter(this, void 0, void 0, function* () {
-            const args = ['checkout', '--progress', '--force'];
+    checkout(ref_1, startPoint_1) {
+        return __awaiter(this, arguments, void 0, function* (ref, startPoint, options = []) {
+            const args = ['checkout', '--progress'];
+            // Add custom options (like --merge) if provided
+            if (options.length > 0) {
+                args.push(...options);
+            }
+            else {
+                // Default behavior - use force
+                args.push('--force');
+            }
             if (startPoint) {
                 args.push('-B', ref, startPoint);
             }
@@ -1025,13 +1033,17 @@ const fs = __importStar(__nccwpck_require__(7147));
 const fsHelper = __importStar(__nccwpck_require__(7219));
 const io = __importStar(__nccwpck_require__(7436));
 const path = __importStar(__nccwpck_require__(1017));
-function prepareExistingDirectory(git, repositoryPath, repositoryUrl, clean, ref) {
-    return __awaiter(this, void 0, void 0, function* () {
+function prepareExistingDirectory(git_1, repositoryPath_1, repositoryUrl_1, clean_1, ref_1) {
+    return __awaiter(this, arguments, void 0, function* (git, repositoryPath, repositoryUrl, clean, ref, preserveLocalChanges = false) {
         var _a;
         assert.ok(repositoryPath, 'Expected repositoryPath to be defined');
         assert.ok(repositoryUrl, 'Expected repositoryUrl to be defined');
         // Indicates whether to delete the directory contents
         let remove = false;
+        // If preserveLocalChanges is true, log it
+        if (preserveLocalChanges) {
+            core.info(`Preserve local changes is enabled, will attempt to keep local files`);
+        }
         // Check whether using git or REST API
         if (!git) {
             remove = true;
@@ -1112,14 +1124,26 @@ function prepareExistingDirectory(git, repositoryPath, repositoryUrl, clean, ref
                 remove = true;
             }
         }
-        if (remove) {
+        if (remove && !preserveLocalChanges) {
             // Delete the contents of the directory. Don't delete the directory itself
             // since it might be the current working directory.
             core.info(`Deleting the contents of '${repositoryPath}'`);
             for (const file of yield fs.promises.readdir(repositoryPath)) {
+                // Skip .git directory as we need it to determine if a file is tracked
+                if (file === '.git') {
+                    continue;
+                }
                 yield io.rmRF(path.join(repositoryPath, file));
             }
         }
+        else if (remove && preserveLocalChanges) {
+            core.info(`Skipping deletion of directory contents due to preserve-local-changes setting`);
+            // We still need to make sure we have a git repository to work with
+            if (!git) {
+                core.info(`Initializing git repository to prepare for checkout with preserved changes`);
+                yield fs.promises.mkdir(path.join(repositoryPath, '.git'), { recursive: true });
+            }
+        }
     });
 }
 
@@ -1216,7 +1240,7 @@ function getSource(settings) {
             }
             // Prepare existing directory, otherwise recreate
             if (isExisting) {
-                yield gitDirectoryHelper.prepareExistingDirectory(git, settings.repositoryPath, repositoryUrl, settings.clean, settings.ref);
+                yield gitDirectoryHelper.prepareExistingDirectory(git, settings.repositoryPath, repositoryUrl, settings.clean, settings.ref, settings.preserveLocalChanges);
             }
             if (!git) {
                 // Downloading using REST API
@@ -1329,7 +1353,104 @@ function getSource(settings) {
             }
             // Checkout
             core.startGroup('Checking out the ref');
-            yield git.checkout(checkoutInfo.ref, checkoutInfo.startPoint);
+            if (settings.preserveLocalChanges) {
+                core.info('Attempting to preserve local changes during checkout');
+                // List and store local files before checkout
+                const fs = __nccwpck_require__(7147);
+                const path = __nccwpck_require__(1017);
+                const localFiles = new Map();
+                try {
+                    // Get all files in the workspace that aren't in the .git directory
+                    const workspacePath = process.cwd();
+                    core.info(`Current workspace path: ${workspacePath}`);
+                    // List all files in the current directory using fs
+                    const listFilesRecursively = (dir) => {
+                        let results = [];
+                        const list = fs.readdirSync(dir);
+                        list.forEach((file) => {
+                            const fullPath = path.join(dir, file);
+                            const relativePath = path.relative(workspacePath, fullPath);
+                            // Skip .git directory
+                            if (relativePath.startsWith('.git'))
+                                return;
+                            const stat = fs.statSync(fullPath);
+                            if (stat && stat.isDirectory()) {
+                                // Recursively explore subdirectories
+                                results = results.concat(listFilesRecursively(fullPath));
+                            }
+                            else {
+                                // Store file content in memory
+                                try {
+                                    const content = fs.readFileSync(fullPath);
+                                    localFiles.set(relativePath, content);
+                                    results.push(relativePath);
+                                }
+                                catch (readErr) {
+                                    core.warning(`Failed to read file ${relativePath}: ${readErr}`);
+                                }
+                            }
+                        });
+                        return results;
+                    };
+                    const localFilesList = listFilesRecursively(workspacePath);
+                    core.info(`Found ${localFilesList.length} local files to preserve:`);
+                    localFilesList.forEach(file => core.info(`  - ${file}`));
+                }
+                catch (error) {
+                    core.warning(`Failed to list local files: ${error}`);
+                }
+                // Perform normal checkout
+                yield git.checkout(checkoutInfo.ref, checkoutInfo.startPoint);
+                // Restore local files that were not tracked by git
+                core.info('Restoring local files after checkout');
+                try {
+                    let restoredCount = 0;
+                    const execOptions = {
+                        cwd: process.cwd(),
+                        silent: true,
+                        ignoreReturnCode: true
+                    };
+                    for (const [filePath, content] of localFiles.entries()) {
+                        // Check if file exists in git using a child process instead of git.execGit
+                        const { exec } = __nccwpck_require__(1514);
+                        let exitCode = 0;
+                        const output = {
+                            stdout: '',
+                            stderr: ''
+                        };
+                        // Capture output
+                        const options = Object.assign(Object.assign({}, execOptions), { listeners: {
+                                stdout: (data) => {
+                                    output.stdout += data.toString();
+                                },
+                                stderr: (data) => {
+                                    output.stderr += data.toString();
+                                }
+                            } });
+                        exitCode = yield exec('git', ['ls-files', '--error-unmatch', filePath], options);
+                        if (exitCode !== 0) {
+                            // File is not tracked by git, safe to restore
+                            const fullPath = path.join(process.cwd(), filePath);
+                            // Ensure directory exists
+                            fs.mkdirSync(path.dirname(fullPath), { recursive: true });
+                            fs.writeFileSync(fullPath, content);
+                            core.info(`Restored local file: ${filePath}`);
+                            restoredCount++;
+                        }
+                        else {
+                            core.info(`Skipping ${filePath} as it's tracked by git`);
+                        }
+                    }
+                    core.info(`Successfully restored ${restoredCount} local files`);
+                }
+                catch (error) {
+                    core.warning(`Failed to restore local files: ${error}`);
+                }
+            }
+            else {
+                // Use the default behavior with --force
+                yield git.checkout(checkoutInfo.ref, checkoutInfo.startPoint);
+            }
             core.endGroup();
             // Submodules
             if (settings.submodules) {
@@ -1766,6 +1887,9 @@ function getInputs() {
         // Clean
         result.clean = (core.getInput('clean') || 'true').toUpperCase() === 'TRUE';
         core.debug(`clean = ${result.clean}`);
+        // Preserve local changes
+        result.preserveLocalChanges = (core.getInput('preserve-local-changes') || 'false').toUpperCase() === 'TRUE';
+        core.debug(`preserveLocalChanges = ${result.preserveLocalChanges}`);
         // Filter
         const filter = core.getInput('filter');
         if (filter) {

src/git-command-manager.ts

@@ -22,7 +22,7 @@ export interface IGitCommandManager {
   disableSparseCheckout(): Promise<void>
   sparseCheckout(sparseCheckout: string[]): Promise<void>
   sparseCheckoutNonConeMode(sparseCheckout: string[]): Promise<void>
-  checkout(ref: string, startPoint: string): Promise<void>
+  checkout(ref: string, startPoint: string, options?: string[]): Promise<void>
   checkoutDetach(): Promise<void>
   config(
     configKey: string,
@@ -203,8 +203,21 @@ class GitCommandManager {
     )
   }
 
-  async checkout(ref: string, startPoint: string): Promise<void> {
-    const args = ['checkout', '--progress', '--force']
+  async checkout(
+    ref: string,
+    startPoint: string,
+    options: string[] = []
+  ): Promise<void> {
+    const args = ['checkout', '--progress']
+
+    // Add custom options (like --merge) if provided
+    if (options.length > 0) {
+      args.push(...options)
+    } else {
+      // Default behavior - use force
+      args.push('--force')
+    }
+
     if (startPoint) {
       args.push('-B', ref, startPoint)
     } else {

src/git-directory-helper.ts

@@ -11,13 +11,19 @@ export async function prepareExistingDirectory(
   repositoryPath: string,
   repositoryUrl: string,
   clean: boolean,
-  ref: string
+  ref: string,
+  preserveLocalChanges: boolean = false
 ): Promise<void> {
   assert.ok(repositoryPath, 'Expected repositoryPath to be defined')
   assert.ok(repositoryUrl, 'Expected repositoryUrl to be defined')
 
   // Indicates whether to delete the directory contents
   let remove = false
+
+  // If preserveLocalChanges is true, log it
+  if (preserveLocalChanges) {
+    core.info(`Preserve local changes is enabled, will attempt to keep local files`)
+  }
 
   // Check whether using git or REST API
   if (!git) {
@@ -114,12 +120,23 @@ export async function prepareExistingDirectory(
     }
   }
 
-  if (remove) {
+  if (remove && !preserveLocalChanges) {
     // Delete the contents of the directory. Don't delete the directory itself
     // since it might be the current working directory.
     core.info(`Deleting the contents of '${repositoryPath}'`)
     for (const file of await fs.promises.readdir(repositoryPath)) {
+      // Skip .git directory as we need it to determine if a file is tracked
+      if (file === '.git') {
+        continue
+      }
       await io.rmRF(path.join(repositoryPath, file))
     }
+  } else if (remove && preserveLocalChanges) {
+    core.info(`Skipping deletion of directory contents due to preserve-local-changes setting`)
+    // We still need to make sure we have a git repository to work with
+    if (!git) {
+      core.info(`Initializing git repository to prepare for checkout with preserved changes`)
+      await fs.promises.mkdir(path.join(repositoryPath, '.git'), { recursive: true })
+    }
   }
 }