New checkpoints algorithm

src/services/checkpoints/CheckpointService.ts

@@ -11,6 +11,12 @@ export type CheckpointServiceOptions = {
 	log?: (message: string) => void
 }
 
+export type StagedFile = {
+	path: string
+	isStaged: boolean
+	isPartiallyStaged: boolean
+}
+
 /**
  * The CheckpointService provides a mechanism for storing a snapshot of the
  * current VSCode workspace each time a Roo Code tool is executed. It uses Git
@@ -23,11 +29,11 @@ export type CheckpointServiceOptions = {
  *  - A hidden branch for storing checkpoints.
  *
  * Saving a checkpoint:
- *  - Current changes are stashed (including untracked files).
+ *  - A temporary branch is created to store the current state.
+ *  - All changes (including untracked files) are staged and committed on the temp branch.
  *  - The hidden branch is reset to match main.
- *  - Stashed changes are applied and committed as a checkpoint on the hidden
- *    branch.
- *  - We return to the main branch with the original state restored.
+ *  - The temporary branch commit is cherry-picked onto the hidden branch.
+ *  - The workspace is restored to its original state and the temp branch is deleted.
  *
  * Restoring a checkpoint:
  *  - The workspace is restored to the state of the specified checkpoint using
@@ -37,6 +43,7 @@ export type CheckpointServiceOptions = {
  *  - Non-destructive version control (main branch remains untouched).
  *  - Preservation of the full history of checkpoints.
  *  - Safe restoration to any previous checkpoint.
+ *  - Atomic checkpoint operations with proper error recovery.
  *
  * NOTES
  *
@@ -122,51 +129,188 @@ export class CheckpointService {
 		return result
 	}
 
+	private async restoreMain({
+		branch,
+		stashSha,
+		force = false,
+	}: {
+		branch: string
+		stashSha: string
+		force?: boolean
+	}) {
+		if (force) {
+			await this.git.checkout(["-f", this.mainBranch])
+		} else {
+			await this.git.checkout(this.mainBranch)
+		}
+
+		if (stashSha) {
+			console.log(`[restoreMain] applying stash ${stashSha}`)
+			await this.git.raw(["stash", "apply", "--index", stashSha])
+		}
+
+		console.log(`[restoreMain] restoring from ${branch}`)
+		await this.git.raw(["restore", "--source", branch, "--worktree", "--", "."])
+	}
+
 	public async saveCheckpoint(message: string) {
 		await this.ensureBranch(this.mainBranch)
 
-		// Create temporary branch with all current changes
-		const tempBranch = `${CheckpointService.STASH_BRANCH}-${Date.now()}`
-		await this.git.checkout(["-b", tempBranch])
+		const status = await this.git.status()
+		console.log(`[saveCheckpoint] status: ${JSON.stringify(status)}`)
+		const stashSha = (await this.git.raw(["stash", "create"])).trim()
+		console.log(`[saveCheckpoint] stashSha: ${stashSha}`)
+		const latestHash = await this.git.revparse([this.hiddenBranch])
+
+		/**
+		 * PHASE: Create stash
+		 * Mutations:
+		 *   - Create branch
+		 *   - Change branch
+		 */
+		const stashBranch = `${CheckpointService.STASH_BRANCH}-${Date.now()}`
+		await this.git.checkout(["-b", stashBranch])
+		this.log(`[saveCheckpoint] created and checked out ${stashBranch}`)
+
+		/**
+		 * Phase: Stage stash
+		 * Mutations: None
+		 * Recovery:
+		 *   - UNDO: Create branch
+		 *   - UNDO: Change branch
+		 */
+		try {
+			await this.git.add(["-A"])
+			const status = await this.git.status()
+			this.log(`[saveCheckpoint] status: ${JSON.stringify(status)}`)
+		} catch (err) {
+			await this.git.checkout(["-f", this.mainBranch])
+			await this.git.branch(["-D", stashBranch]).catch(() => {})
+
+			throw new Error(
+				`[saveCheckpoint] Failed in stage stash phase: ${err instanceof Error ? err.message : String(err)}`,
+			)
+		}
+
+		/**
+		 * Phase: Commit stash
+		 * Mutations:
+		 *   - Commit stash
+		 *   - Change branch
+		 * Recovery:
+		 *   - UNDO: Create branch
+		 *   - UNDO: Change branch
+		 */
+		try {
+			// TODO: Add a test to see if empty commits break this.
+			const tempCommit = await this.git.commit(message, undefined, { "--no-verify": null })
+			this.log(`[saveCheckpoint] tempCommit: ${message} -> ${JSON.stringify(tempCommit)}`)
+		} catch (err) {
+			await this.git.checkout(["-f", this.mainBranch])
+			await this.git.branch(["-D", stashBranch]).catch(() => {})
+
+			throw new Error(
+				`[saveCheckpoint] Failed in stash commit phase: ${err instanceof Error ? err.message : String(err)}`,
+			)
+		}
+
+		/**
+		 * PHASE: Diff
+		 * Mutations:
+		 *   - Checkout hidden branch
+		 * Recovery:
+		 *   - UNDO: Create branch
+		 *   - UNDO: Change branch
+		 *   - UNDO: Commit stash
+		 */
+		let diff
 
 		try {
-			// Stage and commit all changes to temporary branch
-			await this.git.add(["-A"])
-			await this.git.commit(message, undefined, {
-				"--allow-empty": null,
-				"--no-verify": null,
-			})
-
-			// Get the latest commit on the hidden branch before we reset it
-			const latestHash = await this.git.revparse([this.hiddenBranch])
-			await this.git.checkout(this.hiddenBranch)
-
-			try {
-				// Reset hidden branch to match main and apply the changes
-				await this.git.reset(["--hard", this.mainBranch])
-
-				// Cherry-pick the temporary commit
-				const commit = await this.git.raw(["cherry-pick", tempBranch])
-
-				// Return to main branch and cleanup
-				await this.git.checkout(this.mainBranch)
-				await this.git.branch(["-D", tempBranch])
-
-				this.currentCheckpoint = commit
-				return { commit }
-			} catch (err) {
-				// If something went wrong after switching to hidden branch
-				await this.git.reset(["--hard", latestHash])
-				await this.git.checkout(["-f", this.mainBranch])
-				await this.git.branch(["-D", tempBranch])
-				throw err
-			}
+			diff = await this.git.diff([latestHash, stashBranch])
 		} catch (err) {
-			// If something went wrong before switching to hidden branch
-			await this.git.checkout(["-f", this.mainBranch])
-			await this.git.branch(["-D", tempBranch])
-			throw new Error(`Failed to save checkpoint: ${err instanceof Error ? err.message : String(err)}`)
+			await this.restoreMain({ branch: stashBranch, stashSha, force: true })
+			await this.git.branch(["-D", stashBranch]).catch(() => {})
+
+			throw new Error(
+				`[saveCheckpoint] Failed in diff phase: ${err instanceof Error ? err.message : String(err)}`,
+			)
 		}
+
+		if (!diff) {
+			this.log("[saveCheckpoint] no diff")
+			await this.restoreMain({ branch: stashBranch, stashSha })
+			await this.git.branch(["-D", stashBranch])
+			return undefined
+		}
+
+		/**
+		 * PHASE: Reset
+		 * Mutations:
+		 *   - Reset hidden branch
+		 * Recovery:
+		 *   - UNDO: Create branch
+		 *   - UNDO: Change branch
+		 *   - UNDO: Commit stash
+		 */
+		try {
+			await this.git.checkout(this.hiddenBranch)
+			this.log(`[saveCheckpoint] checked out ${this.hiddenBranch}`)
+			await this.git.reset(["--hard", this.mainBranch])
+			this.log(`[saveCheckpoint] reset ${this.hiddenBranch}`)
+		} catch (err) {
+			await this.restoreMain({ branch: stashBranch, stashSha, force: true })
+			await this.git.branch(["-D", stashBranch]).catch(() => {})
+
+			throw new Error(
+				`[saveCheckpoint] Failed in reset phase: ${err instanceof Error ? err.message : String(err)}`,
+			)
+		}
+
+		/**
+		 * PHASE: Cherry pick
+		 * Mutations:
+		 *   - Hidden commit (NOTE: reset on hidden branch no longer needed in
+		 *     success scenario.)
+		 * Recovery:
+		 *   - UNDO: Create branch
+		 *   - UNDO: Change branch
+		 *   - UNDO: Commit stash
+		 *   - UNDO: Reset hidden branch
+		 */
+		let commit = ""
+
+		try {
+			try {
+				await this.git.raw(["cherry-pick", stashBranch])
+			} catch (err) {
+				// Check if we're in the middle of a cherry-pick.
+				// If the cherry-pick resulted in an empty commit (e.g., only
+				// deletions) then complete it with --allow-empty.
+				// Otherwise, rethrow the error.
+				if (existsSync(path.join(this.baseDir, ".git/CHERRY_PICK_HEAD"))) {
+					await this.git.raw(["commit", "--allow-empty", "--no-edit"])
+				} else {
+					throw err
+				}
+			}
+
+			commit = await this.git.revparse(["HEAD"])
+			this.currentCheckpoint = commit
+			this.log(`[saveCheckpoint] cherry-pick commit = ${commit}`)
+		} catch (err) {
+			await this.git.reset(["--hard", latestHash]).catch(() => {})
+			await this.restoreMain({ branch: stashBranch, stashSha, force: true })
+			await this.git.branch(["-D", stashBranch]).catch(() => {})
+
+			throw new Error(
+				`[saveCheckpoint] Failed in cherry pick phase: ${err instanceof Error ? err.message : String(err)}`,
+			)
+		}
+
+		await this.restoreMain({ branch: stashBranch, stashSha })
+		await this.git.branch(["-D", stashBranch])
+
+		return { commit }
 	}
 
 	public async restoreCheckpoint(commitHash: string) {
@@ -264,12 +408,12 @@ export class CheckpointService {
 		const currentBranch = await git.revparse(["--abbrev-ref", "HEAD"])
 		const currentSha = await git.revparse(["HEAD"])
 
-		const hiddenBranch = `roo-code-checkpoints-${taskId}`
+		const hiddenBranch = `${CheckpointService.CHECKPOINT_BRANCH}-${taskId}`
 		const branchSummary = await git.branch()
 
 		if (!branchSummary.all.includes(hiddenBranch)) {
-			await git.checkoutBranch(hiddenBranch, currentBranch) // git checkout -b <hiddenBranch> <currentBranch>
-			await git.checkout(currentBranch) // git checkout <currentBranch>
+			await git.checkoutBranch(hiddenBranch, currentBranch)
+			await git.checkout(currentBranch)
 		}
 
 		return { currentBranch, currentSha, hiddenBranch }

src/services/checkpoints/__tests__/CheckpointService.test.ts

@@ -68,7 +68,7 @@ describe("CheckpointService", () => {
 
 		git = repo.git
 		testFile = repo.testFile
-		service = await CheckpointService.create({ taskId, git, baseDir, log: () => {} })
+		service = await CheckpointService.create({ taskId, git, baseDir })
 	})
 
 	afterEach(async () => {
@@ -295,8 +295,11 @@ describe("CheckpointService", () => {
 			await fs.writeFile(testFile, "I am tracked!")
 			const untrackedFile = path.join(service.baseDir, "new.txt")
 			await fs.writeFile(untrackedFile, "I am untracked!")
+
 			const commit1 = await service.saveCheckpoint("First checkpoint")
 			expect(commit1?.commit).toBeTruthy()
+			expect(await fs.readFile(testFile, "utf-8")).toBe("I am tracked!")
+			expect(await fs.readFile(untrackedFile, "utf-8")).toBe("I am untracked!")
 
 			await fs.unlink(testFile)
 			await fs.unlink(untrackedFile)