feat(infra/git): worktree add/remove/list with porcelain parser

internal/infra/git/worktree.go

@@ -0,0 +1,85 @@
+package git
+
+import (
+	"bufio"
+	"bytes"
+	"context"
+	"strings"
+)
+
+// WorktreeAdd 在 dir（main worktree）创建一个支线 worktree。
+//
+//	path:   绝对路径，由 workspace 包计算
+//	branch: 用 -B 强制创建/重置 — 已存在的分支会被 reset 到 origin/HEAD
+//	        （本地未推送 commit 会丢失，可从 reflog 找回）；--track 让分支
+//	        默认 track origin/HEAD（通常是 main），首次 push 时由 service
+//	        层 set-upstream 到对应远端分支。
+//
+// 失败时如果 stderr 含 "already exists" / "is already used by worktree"，
+// errors.IsConflict 返回 true，调用方应映射为 WORKTREE_BRANCH_CONFLICT。
+func (r *DefaultRunner) WorktreeAdd(ctx context.Context, dir, branch, path string) error {
+	ctx, cancel := withCtx(ctx, r.cfg.OpsTimeout)
+	defer cancel()
+	args := []string{"worktree", "add", "--track", "-B", branch, path}
+	_, _, err := r.exec(ctx, dir, nil, args...)
+	return err
+}
+
+// WorktreeRemove 删除 path 这个 worktree（包含磁盘目录）。
+// 即使 worktree 当前不存在 / 已被外部 rm 掉，调用 git worktree remove --force 也会成功
+// 或返回特定 stderr，调用方据此决定是否吞错。
+func (r *DefaultRunner) WorktreeRemove(ctx context.Context, dir, path string) error {
+	ctx, cancel := withCtx(ctx, r.cfg.OpsTimeout)
+	defer cancel()
+	_, _, err := r.exec(ctx, dir, nil, "worktree", "remove", "--force", path)
+	return err
+}
+
+// WorktreeList 返回 dir 下所有 worktree 的元数据（含 main）。
+func (r *DefaultRunner) WorktreeList(ctx context.Context, dir string) ([]Worktree, error) {
+	ctx, cancel := withCtx(ctx, r.cfg.OpsTimeout)
+	defer cancel()
+	out, _, err := r.exec(ctx, dir, nil, "worktree", "list", "--porcelain")
+	if err != nil {
+		return nil, err
+	}
+	return parseWorktreeList(out), nil
+}
+
+// parseWorktreeList 解析 git worktree list --porcelain 输出。
+// 每个 worktree 由若干 KV 行组成，记录间空行分隔：
+//
+//	worktree /abs/path
+//	HEAD     <sha>
+//	branch   refs/heads/<name>     (or "detached")
+//	bare                            (only for bare main)
+func parseWorktreeList(buf []byte) []Worktree {
+	var out []Worktree
+	var cur Worktree
+	flush := func() {
+		if cur.Path != "" {
+			out = append(out, cur)
+		}
+		cur = Worktree{}
+	}
+	sc := bufio.NewScanner(bytes.NewReader(buf))
+	for sc.Scan() {
+		line := sc.Text()
+		if line == "" {
+			flush()
+			continue
+		}
+		switch {
+		case strings.HasPrefix(line, "worktree "):
+			cur.Path = strings.TrimPrefix(line, "worktree ")
+		case strings.HasPrefix(line, "HEAD "):
+			cur.HEAD = strings.TrimPrefix(line, "HEAD ")
+		case strings.HasPrefix(line, "branch "):
+			cur.Branch = strings.TrimPrefix(strings.TrimPrefix(line, "branch "), "refs/heads/")
+		case line == "bare":
+			cur.Bare = true
+		}
+	}
+	flush()
+	return out
+}

internal/infra/git/worktree_test.go

@@ -0,0 +1,51 @@
+package git
+
+import (
+	"context"
+	"path/filepath"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestWorktree_AddListRemove(t *testing.T) {
+	t.Parallel()
+	gitAvailable(t)
+	bare := makeBareRepo(t)
+	r := newTestRunner(t)
+	main := filepath.Join(t.TempDir(), "main")
+	ctx, cancel := context.WithTimeout(context.Background(), 60*time.Second)
+	defer cancel()
+	require.NoError(t, r.Clone(ctx, main, bare, "main", nil))
+
+	feat := filepath.Join(filepath.Dir(main), "feat-x")
+	require.NoError(t, r.WorktreeAdd(ctx, main, "feat-x", feat))
+
+	list, err := r.WorktreeList(ctx, main)
+	require.NoError(t, err)
+	require.GreaterOrEqual(t, len(list), 2)
+	var found bool
+	for _, w := range list {
+		if w.Branch == "feat-x" {
+			found = true
+		}
+	}
+	require.True(t, found, "feat-x worktree not in list")
+
+	require.NoError(t, r.WorktreeRemove(ctx, main, feat))
+	list, err = r.WorktreeList(ctx, main)
+	require.NoError(t, err)
+	for _, w := range list {
+		require.NotEqual(t, "feat-x", w.Branch)
+	}
+}
+
+func TestParseWorktreeList(t *testing.T) {
+	t.Parallel()
+	buf := []byte("worktree /m\nHEAD aaa\nbranch refs/heads/main\n\nworktree /f\nHEAD bbb\nbranch refs/heads/feat-x\n\n")
+	got := parseWorktreeList(buf)
+	require.Len(t, got, 2)
+	require.Equal(t, "main", got[0].Branch)
+	require.Equal(t, "feat-x", got[1].Branch)
+}