feat: preflight update runner before rebase

src/infra/update-runner.test.ts

@@ -74,7 +74,9 @@ describe("runGatewayUpdate", () => {
         stdout: "origin/main",
       },
       [`git -C ${tempDir} fetch --all --prune --tags`]: { stdout: "" },
-      [`git -C ${tempDir} rebase @{upstream}`]: { code: 1, stderr: "conflict" },
+      [`git -C ${tempDir} rev-parse @{upstream}`]: { stdout: "upstream123" },
+      [`git -C ${tempDir} rev-list --max-count=10 upstream123`]: { stdout: "upstream123\n" },
+      [`git -C ${tempDir} rebase upstream123`]: { code: 1, stderr: "conflict" },
       [`git -C ${tempDir} rebase --abort`]: { stdout: "" },
     });
 

src/infra/update-runner.ts

@@ -1,4 +1,5 @@
 import fs from "node:fs/promises";
+import os from "node:os";
 import path from "node:path";
 
 import { type CommandOptions, runCommandWithTimeout } from "../process/exec.js";
@@ -63,6 +64,7 @@ type UpdateRunnerOptions = {
 
 const DEFAULT_TIMEOUT_MS = 20 * 60_000;
 const MAX_LOG_CHARS = 8000;
+const PREFLIGHT_MAX_COMMITS = 10;
 const START_DIRS = ["cwd", "argv1", "process"];
 
 function normalizeDir(value?: string | null) {
@@ -420,8 +422,152 @@ export async function runGatewayUpdate(opts: UpdateRunnerOptions = {}): Promise<
       );
       steps.push(fetchStep);
 
+      const upstreamShaStep = await runStep(
+        step(
+          "git rev-parse @{upstream}",
+          ["git", "-C", gitRoot, "rev-parse", "@{upstream}"],
+          gitRoot,
+        ),
+      );
+      steps.push(upstreamShaStep);
+      const upstreamSha = upstreamShaStep.stdoutTail?.trim();
+      if (!upstreamShaStep.stdoutTail || !upstreamSha) {
+        return {
+          status: "error",
+          mode: "git",
+          root: gitRoot,
+          reason: "no-upstream-sha",
+          before: { sha: beforeSha, version: beforeVersion },
+          steps,
+          durationMs: Date.now() - startedAt,
+        };
+      }
+
+      const revListStep = await runStep(
+        step(
+          "git rev-list",
+          ["git", "-C", gitRoot, "rev-list", `--max-count=${PREFLIGHT_MAX_COMMITS}`, upstreamSha],
+          gitRoot,
+        ),
+      );
+      steps.push(revListStep);
+      if (revListStep.exitCode !== 0) {
+        return {
+          status: "error",
+          mode: "git",
+          root: gitRoot,
+          reason: "preflight-revlist-failed",
+          before: { sha: beforeSha, version: beforeVersion },
+          steps,
+          durationMs: Date.now() - startedAt,
+        };
+      }
+
+      const candidates = (revListStep.stdoutTail ?? "")
+        .split("\n")
+        .map((line) => line.trim())
+        .filter(Boolean);
+      if (candidates.length === 0) {
+        return {
+          status: "error",
+          mode: "git",
+          root: gitRoot,
+          reason: "preflight-no-candidates",
+          before: { sha: beforeSha, version: beforeVersion },
+          steps,
+          durationMs: Date.now() - startedAt,
+        };
+      }
+
+      const manager = await detectPackageManager(gitRoot);
+      const preflightRoot = await fs.mkdtemp(path.join(os.tmpdir(), "clawdbot-update-preflight-"));
+      const worktreeDir = path.join(preflightRoot, "worktree");
+      const worktreeStep = await runStep(
+        step(
+          "preflight worktree",
+          ["git", "-C", gitRoot, "worktree", "add", "--detach", worktreeDir, upstreamSha],
+          gitRoot,
+        ),
+      );
+      steps.push(worktreeStep);
+      if (worktreeStep.exitCode !== 0) {
+        await fs.rm(preflightRoot, { recursive: true, force: true }).catch(() => {});
+        return {
+          status: "error",
+          mode: "git",
+          root: gitRoot,
+          reason: "preflight-worktree-failed",
+          before: { sha: beforeSha, version: beforeVersion },
+          steps,
+          durationMs: Date.now() - startedAt,
+        };
+      }
+
+      let selectedSha: string | null = null;
+      try {
+        for (const sha of candidates) {
+          const shortSha = sha.slice(0, 8);
+          const checkoutStep = await runStep(
+            step(
+              `preflight checkout (${shortSha})`,
+              ["git", "-C", worktreeDir, "checkout", "--detach", sha],
+              worktreeDir,
+            ),
+          );
+          steps.push(checkoutStep);
+          if (checkoutStep.exitCode !== 0) continue;
+
+          const depsStep = await runStep(
+            step(`preflight deps install (${shortSha})`, managerInstallArgs(manager), worktreeDir),
+          );
+          steps.push(depsStep);
+          if (depsStep.exitCode !== 0) continue;
+
+          const lintStep = await runStep(
+            step(`preflight lint (${shortSha})`, managerScriptArgs(manager, "lint"), worktreeDir),
+          );
+          steps.push(lintStep);
+          if (lintStep.exitCode !== 0) continue;
+
+          const buildStep = await runStep(
+            step(`preflight build (${shortSha})`, managerScriptArgs(manager, "build"), worktreeDir),
+          );
+          steps.push(buildStep);
+          if (buildStep.exitCode !== 0) continue;
+
+          selectedSha = sha;
+          break;
+        }
+      } finally {
+        const removeStep = await runStep(
+          step(
+            "preflight cleanup",
+            ["git", "-C", gitRoot, "worktree", "remove", "--force", worktreeDir],
+            gitRoot,
+          ),
+        );
+        steps.push(removeStep);
+        await runCommand(["git", "-C", gitRoot, "worktree", "prune"], {
+          cwd: gitRoot,
+          timeoutMs,
+        }).catch(() => null);
+        await fs.rm(preflightRoot, { recursive: true, force: true }).catch(() => {});
+      }
+
+      if (!selectedSha) {
+        return {
+          status: "error",
+          mode: "git",
+          root: gitRoot,
+          reason: "preflight-no-good-commit",
+          before: { sha: beforeSha, version: beforeVersion },
+          steps,
+          durationMs: Date.now() - startedAt,
+        };
+      }
+
       const rebaseStep = await runStep(
-        step("git rebase", ["git", "-C", gitRoot, "rebase", "@{upstream}"], gitRoot),
+        step("git rebase", ["git", "-C", gitRoot, "rebase", selectedSha], gitRoot),
       );
       steps.push(rebaseStep);
       if (rebaseStep.exitCode !== 0) {