feat(FN-4485): complete Step 2 — tighten branch conflict classifier

Fusion-Task-Id: FN-4485
Fusion-Task-Lineage: 034088dc-ebc4-4e12-8314-39419d41b23f

packages/engine/src/__tests__/branch-conflicts-self-owned.test.ts

@@ -0,0 +1,178 @@
+import { beforeEach, describe, expect, it, vi } from "vitest";
+import type { ExecException } from "node:child_process";
+
+vi.mock("node:child_process", async () => {
+  const { promisify } = await import("node:util");
+  const execSyncFn = vi.fn();
+
+  const execFn: any = vi.fn((cmd: string, opts: any, cb: any) => {
+    const callback = typeof opts === "function" ? opts : cb;
+    const options = typeof opts === "function" ? {} : (opts ?? {});
+    try {
+      const out = execSyncFn(cmd, { ...options, stdio: ["pipe", "pipe", "pipe"] });
+      const stdout = out === undefined ? "" : out.toString();
+      if (typeof callback === "function") callback(null, stdout, "");
+    } catch (err) {
+      if (typeof callback === "function") {
+        const error = err as ExecException & { stdout?: string; stderr?: string };
+        callback(err, error?.stdout?.toString?.() ?? "", error?.stderr?.toString?.() ?? "");
+      }
+    }
+  });
+
+  execFn[promisify.custom] = (cmd: string, opts?: any) =>
+    new Promise((resolve, reject) => {
+      execFn(cmd, opts, (err: any, stdout: string, stderr: string) => {
+        if (err) {
+          (err as Record<string, unknown>).stdout = stdout;
+          (err as Record<string, unknown>).stderr = stderr;
+          reject(err);
+        } else {
+          resolve({ stdout, stderr });
+        }
+      });
+    });
+
+  return { exec: execFn, execSync: execSyncFn };
+});
+
+vi.mock("node:fs", () => ({
+  existsSync: vi.fn(),
+}));
+
+import { execSync } from "node:child_process";
+import { existsSync } from "node:fs";
+import { inspectBranchConflict } from "../branch-conflicts.js";
+
+const mockedExecSync = vi.mocked(execSync);
+const mockedExistsSync = vi.mocked(existsSync);
+
+describe("branch-conflicts self-owned classifier", () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+    mockedExistsSync.mockReturnValue(true);
+  });
+
+  it("returns reclaimable for self-owned branch with zero task-attributed commits", async () => {
+    mockedExecSync.mockImplementation((cmd: string | string[]) => {
+      const command = typeof cmd === "string" ? cmd : cmd[0];
+      if (command === "git worktree prune") return Buffer.from("");
+      if (command === "git worktree list --porcelain") {
+        return Buffer.from(["worktree /tmp/wt-fn-4485", "HEAD 222", "branch refs/heads/fusion/fn-4485", ""].join("\n"));
+      }
+      if (command.includes("git rev-parse --verify 'refs/heads/fusion/fn-4485^{commit}'")) return Buffer.from("tipsha\n");
+      if (command.includes("git rev-parse --verify 'fusion/fn-4485^{commit}'")) return Buffer.from("tipsha\n");
+      if (command.includes("git rev-parse --verify 'main^{commit}'")) return Buffer.from("mainsha\n");
+      if (command === "git merge-base 'main' 'fusion/fn-4485'") return Buffer.from("base123\n");
+      if (command === "git cherry 'main' 'fusion/fn-4485' 'base123'") return Buffer.from("+ aaa111\n");
+      if (command.includes("git rev-parse --verify 'aaa111^{commit}'")) return Buffer.from("aaa111\n");
+      if (command === "git log -1 --format=%s 'aaa111'") return Buffer.from("prior work\n");
+      if (command.includes("git log --format=%H%x00%s%x00%b 'main..fusion/fn-4485'")) {
+        return Buffer.from("aaa111\u0000chore: prior work\u0000\u0000");
+      }
+      throw new Error(`Unexpected command: ${command}`);
+    });
+
+    const result = await inspectBranchConflict({
+      repoDir: "/tmp/repo",
+      branchName: "fusion/fn-4485",
+      conflictingWorktreePath: "/tmp/wt-fn-4485",
+      requestingTaskId: "FN-4485",
+      ownerTaskId: "FN-4485",
+      startPoint: "main",
+    });
+
+    expect(result.kind).toBe("reclaimable");
+    if (result.kind !== "reclaimable") throw new Error("expected reclaimable");
+    expect(result.taskAttributedCommitCount).toBe(0);
+  });
+
+  it("returns reclaimable for self-owned branch with positive task-attributed commits", async () => {
+    mockedExecSync.mockImplementation((cmd: string | string[]) => {
+      const command = typeof cmd === "string" ? cmd : cmd[0];
+      if (command === "git worktree prune") return Buffer.from("");
+      if (command === "git worktree list --porcelain") {
+        return Buffer.from(["worktree /tmp/wt-fn-4485", "HEAD 222", "branch refs/heads/fusion/fn-4485", ""].join("\n"));
+      }
+      if (command.includes("git rev-parse --verify 'refs/heads/fusion/fn-4485^{commit}'")) return Buffer.from("tipsha\n");
+      if (command.includes("git rev-parse --verify 'fusion/fn-4485^{commit}'")) return Buffer.from("tipsha\n");
+      if (command.includes("git rev-parse --verify 'main^{commit}'")) return Buffer.from("mainsha\n");
+      if (command === "git merge-base 'main' 'fusion/fn-4485'") return Buffer.from("base123\n");
+      if (command === "git cherry 'main' 'fusion/fn-4485' 'base123'") return Buffer.from("+ aaa111\n");
+      if (command.includes("git rev-parse --verify 'aaa111^{commit}'")) return Buffer.from("aaa111\n");
+      if (command === "git log -1 --format=%s 'aaa111'") return Buffer.from("owned work\n");
+      if (command.includes("git log --format=%H%x00%s%x00%b 'main..fusion/fn-4485'")) {
+        return Buffer.from("aaa111\u0000feat(FN-4485): owned\u0000Fusion-Task-Id: FN-4485\u0000");
+      }
+      throw new Error(`Unexpected command: ${command}`);
+    });
+
+    const result = await inspectBranchConflict({
+      repoDir: "/tmp/repo",
+      branchName: "fusion/fn-4485",
+      conflictingWorktreePath: "/tmp/wt-fn-4485",
+      requestingTaskId: "FN-4485",
+      startPoint: "main",
+    });
+
+    expect(result.kind).toBe("reclaimable");
+    if (result.kind !== "reclaimable") throw new Error("expected reclaimable");
+    expect(result.taskAttributedCommitCount).toBe(1);
+  });
+
+  it("keeps foreign worktree conflicts as live-foreign", async () => {
+    mockedExecSync.mockImplementation((cmd: string | string[]) => {
+      const command = typeof cmd === "string" ? cmd : cmd[0];
+      if (command === "git worktree prune") return Buffer.from("");
+      if (command === "git worktree list --porcelain") {
+        return Buffer.from(["worktree /tmp/wt-fn-9999", "HEAD 222", "branch refs/heads/topic/other", ""].join("\n"));
+      }
+      if (command.includes("git rev-parse --verify 'refs/heads/topic/other^{commit}'")) return Buffer.from("tipsha\n");
+      if (command.includes("git rev-parse --verify 'topic/other^{commit}'")) return Buffer.from("tipsha\n");
+      if (command.includes("git rev-parse --verify 'main^{commit}'")) return Buffer.from("mainsha\n");
+      if (command === "git merge-base 'main' 'topic/other'") return Buffer.from("base123\n");
+      if (command === "git cherry 'main' 'topic/other' 'base123'") return Buffer.from("+ aaa111\n");
+      if (command.includes("git rev-parse --verify 'aaa111^{commit}'")) return Buffer.from("aaa111\n");
+      if (command === "git log -1 --format=%s 'aaa111'") return Buffer.from("foreign work\n");
+      if (command.includes("git log --format=%H%x00%s%x00%b 'main..topic/other'")) {
+        return Buffer.from("aaa111\u0000feat(FN-9999): foreign\u0000Fusion-Task-Id: FN-9999\u0000");
+      }
+      throw new Error(`Unexpected command: ${command}`);
+    });
+
+    const result = await inspectBranchConflict({
+      repoDir: "/tmp/repo",
+      branchName: "topic/other",
+      conflictingWorktreePath: "/tmp/requesting-wt",
+      requestingTaskId: "FN-4485",
+      ownerTaskId: "FN-4485",
+      startPoint: "main",
+    });
+
+    expect(result.kind).toBe("live-foreign");
+  });
+
+  it("keeps stale-resolved when branch ref is gone", async () => {
+    mockedExecSync.mockImplementation((cmd: string | string[]) => {
+      const command = typeof cmd === "string" ? cmd : cmd[0];
+      if (command === "git worktree prune") return Buffer.from("");
+      if (command === "git worktree list --porcelain") {
+        return Buffer.from(["worktree /tmp/wt", "HEAD 222", "branch refs/heads/main", ""].join("\n"));
+      }
+      if (command.includes("git rev-parse --verify 'refs/heads/fusion/fn-4485^{commit}'")) {
+        throw new Error("missing");
+      }
+      throw new Error(`Unexpected command: ${command}`);
+    });
+
+    const result = await inspectBranchConflict({
+      repoDir: "/tmp/repo",
+      branchName: "fusion/fn-4485",
+      conflictingWorktreePath: "/tmp/wt-fn-4485",
+      requestingTaskId: "FN-4485",
+      startPoint: "main",
+    });
+
+    expect(result).toEqual({ kind: "stale-resolved" });
+  });
+});