add confirm-destructive, git-checkpoint, notify extensions

extensions/git-checkpoint.ts

@@ -0,0 +1,76 @@
+/**
+ * Git Checkpoint Extension
+ *
+ * Creates a git stash checkpoint at the start of each turn, keyed to the
+ * session entry ID. If you /fork from a past entry, you're offered the option
+ * to restore the code state from that point.
+ *
+ * Silently skips turns where the working directory isn't inside a git repo or
+ * where there are no changes to stash.
+ *
+ * Status bar shows the number of checkpoints saved in the current session.
+ */
+
+import type { ExtensionAPI } from "@mariozechner/pi-coding-agent";
+
+export default function (pi: ExtensionAPI) {
+  // entryId → stash ref (e.g. "refs/stash" or a full sha)
+  const checkpoints = new Map<string, string>();
+
+  async function inGitRepo(): Promise<boolean> {
+    try {
+      const result = await pi.exec("git", ["rev-parse", "--git-dir"]);
+      return result.exitCode === 0;
+    } catch {
+      return false;
+    }
+  }
+
+  function updateStatus(ctx: { ui: { setStatus: (id: string, text: string) => void } }): void {
+    const n = checkpoints.size;
+    if (n > 0) {
+      ctx.ui.setStatus("git-checkpoint", `⎇ ${n} checkpoint${n === 1 ? "" : "s"}`);
+    } else {
+      ctx.ui.setStatus("git-checkpoint", "");
+    }
+  }
+
+  pi.on("turn_start", async (_event, ctx) => {
+    if (!(await inGitRepo())) return;
+
+    // Capture the current entry ID at turn start — this is the entry the
+    // user will fork from if they want to restore code to this point.
+    const entryId = ctx.sessionManager.getLeafId();
+    if (!entryId) return;
+
+    // git stash create makes a stash object without touching the working tree.
+    // Returns the stash ref on stdout, or empty string if nothing to stash.
+    const result = await pi.exec("git", ["stash", "create"]);
+    const ref = result.stdout.trim();
+
+    if (ref) {
+      checkpoints.set(entryId, ref);
+      updateStatus(ctx);
+    }
+  });
+
+  pi.on("session_before_fork", async (event, ctx) => {
+    const ref = checkpoints.get(event.entryId);
+    if (!ref) return;
+    if (!ctx.hasUI) return;
+
+    const choice = await ctx.ui.select(
+      "Restore code to this checkpoint?",
+      ["Yes, restore code state", "No, keep current code"],
+    );
+
+    if (choice?.startsWith("Yes")) {
+      await pi.exec("git", ["stash", "apply", ref]);
+      ctx.ui.notify("Code restored to checkpoint", "success");
+    }
+  });
+
+  pi.on("session_shutdown", () => {
+    checkpoints.clear();
+  });
+}