Add utility to restore back up files

Author: mayank1513

lib/.merge-backups/tmp-test/clean.txt

@@ -1,7 +1,7 @@
 import { describe, it, expect, beforeAll, afterAll } from "vitest";
 import fs from "node:fs/promises";
 import path from "node:path";
-import { hasConflict, createSkipDirectoryMatcher, listMatchingFiles, backupFile } from "./utils"; // adjust import
+import { hasConflict, listMatchingFiles, backupFile, restoreBackups } from "./utils"; // adjust import
 import { basicMatcher } from "./matcher";
 
 const matcher = basicMatcher;
@@ -26,6 +26,7 @@ beforeAll(async () => {
 
 afterAll(async () => {
   await fs.rm(TMP, { recursive: true, force: true });
+  await fs.rm(".merge-backups", { recursive: true, force: true });
 });
 
 describe("hasConflict", () => {
@@ -83,3 +84,33 @@ describe("backupFile", () => {
     expect(backup).toMatch(/\.merge-backups/);
   });
 });
+
+describe("restoreBackups", () => {
+  it("restores files from backup directory", async () => {
+    process.chdir(TMP);
+    const backupDir = "test-backup";
+    const testFile = "restore-test.txt";
+
+    await fs.mkdir(backupDir, { recursive: true });
+    await fs.writeFile(path.join(backupDir, "restore-test.txt"), "restored");
+
+    await restoreBackups(backupDir);
+
+    const content = await fs.readFile(testFile, "utf8");
+    expect(content).toBe("restored");
+  });
+
+  it("restores nested directory structure", async () => {
+    const backupDir = "nested-backup";
+    const nestedDir = path.join(backupDir, "sub", "deep");
+
+    await fs.mkdir(nestedDir, { recursive: true });
+    await fs.writeFile(path.join(nestedDir, "nested.txt"), "deep file");
+
+    await restoreBackups(backupDir);
+
+    const content = await fs.readFile(path.join("sub", "deep", "nested.txt"), "utf8");
+    expect(content).toBe("deep file");
+    process.chdir("..");
+  });
+});

lib/src/utils.test.ts

@@ -19,7 +19,7 @@ export const hasConflict = (content: string): boolean => {
 
 export type CollectFilesOptions = Pick<
   NormalizedConfig,
-  "include" | "exclude" | "matcher" | "includeNonConflicted" | "debug"
+  "include" | "exclude" | "matcher" | "includeNonConflicted" | "debug" | "backupDir"
 > & {
   /** Root directory to start traversal (defaults to `process.cwd()`). */
   root?: string;
@@ -34,9 +34,15 @@ export type CollectFilesOptions = Pick<
  * @param options - Collection options, including `fileFilter` and traversal root.
  * @returns A promise that resolves with an array of `{ filePath, content }`.
  */
-export const listMatchingFiles = async (options: CollectFilesOptions): Promise<FileEntry[]> => {
-  const { root = process.cwd(), include, exclude, matcher, includeNonConflicted, debug } = options;
-
+export const listMatchingFiles = async ({
+  root = process.cwd(),
+  include,
+  exclude,
+  matcher,
+  includeNonConflicted,
+  debug,
+  backupDir,
+}: CollectFilesOptions): Promise<FileEntry[]> => {
   for (const p of [...include, ...exclude]) {
     if (p.startsWith("!")) throw new Error(`Negation not allowed in include/exclude: ${p}`);
     if (p.includes("\\")) console.warn(`Use '/' as path separator: ${p}`);
@@ -47,7 +53,11 @@ export const listMatchingFiles = async (options: CollectFilesOptions): Promise<F
     return matcher.isMatch(posixPath, include) && !matcher.isMatch(posixPath, exclude);
   };
 
-  const skipDirMatcher = createSkipDirectoryMatcher(include, exclude, matcher);
+  const skipDirMatcher = createSkipDirectoryMatcher(
+    include,
+    backupDir ? [...exclude, backupDir] : exclude,
+    matcher,
+  );
 
   const fileEntries: FileEntry[] = [];
 
@@ -147,3 +157,24 @@ export const backupFile = async (filePath: string, backupDir = ".merge-backups")
 
   return backupPath;
 };
+
+export const restoreBackups = async (backupDir = ".merge-backups") => {
+  const walk = async (dir: string, relativeDir = "") => {
+    const entries = await fs.readdir(dir, { withFileTypes: true });
+    
+    for (const entry of entries) {
+      const srcPath = path.join(dir, entry.name);
+      const relativePath = path.join(relativeDir, entry.name);
+      const destPath = path.join(process.cwd(), relativePath);
+      
+      if (entry.isDirectory()) {
+        await walk(srcPath, relativePath);
+      } else {
+        await fs.mkdir(path.dirname(destPath), { recursive: true });
+        await fs.copyFile(srcPath, destPath);
+      }
+    }
+  };
+  
+  await walk(backupDir);
+};