feat(infra/git): Runner interface + Credential injection + GitError

internal/infra/git/errors.go

@@ -0,0 +1,91 @@
+package git
+
+import (
+	"errors"
+	"fmt"
+)
+
+// GitError 是 git 子进程返回非零或超时时的统一错误形式。Stderr 已截断 ≤2000 字符；
+// 上层（workspace.Service）会根据 stderr 内容映射到具体业务错误码。
+type GitError struct {
+	Args     []string
+	ExitCode int
+	Stderr   string
+	Cause    error
+}
+
+func (e *GitError) Error() string {
+	return fmt.Sprintf("git %v: exit %d: %s", e.Args, e.ExitCode, e.Stderr)
+}
+
+func (e *GitError) Unwrap() error { return e.Cause }
+
+// IsAuthError 通过 stderr 关键字识别 401/403 类型的远端拒绝（PAT 失效、SSH key
+// 不被信任等）。grep 的关键字源自常见 git 远端的英文响应；模糊但可用。
+func IsAuthError(err error) bool {
+	var ge *GitError
+	if !errors.As(err, &ge) {
+		return false
+	}
+	for _, k := range []string{
+		"Authentication failed",
+		"could not read Username",
+		"Permission denied (publickey)",
+		"403 Forbidden",
+		"401 Unauthorized",
+		"fatal: Authentication",
+	} {
+		if containsCase(ge.Stderr, k) {
+			return true
+		}
+	}
+	return false
+}
+
+// IsConflict 用于识别 "branch already exists" 等 worktree add 冲突场景。
+func IsConflict(err error) bool {
+	var ge *GitError
+	if !errors.As(err, &ge) {
+		return false
+	}
+	for _, k := range []string{
+		"already exists",
+		"is already checked out",
+		"already used by worktree",
+	} {
+		if containsCase(ge.Stderr, k) {
+			return true
+		}
+	}
+	return false
+}
+
+// containsCase 大小写不敏感子串匹配；避免引入 strings.EqualFold 之类逐字符开销。
+func containsCase(s, sub string) bool {
+	if len(sub) == 0 || len(s) < len(sub) {
+		return false
+	}
+	S, Sub := lower(s), lower(sub)
+	return indexOf(S, Sub) >= 0
+}
+
+func lower(s string) string {
+	b := make([]byte, len(s))
+	for i := 0; i < len(s); i++ {
+		c := s[i]
+		if c >= 'A' && c <= 'Z' {
+			c += 'a' - 'A'
+		}
+		b[i] = c
+	}
+	return string(b)
+}
+
+func indexOf(s, sub string) int {
+	for i := 0; i+len(sub) <= len(s); i++ {
+		if s[i:i+len(sub)] == sub {
+			return i
+		}
+	}
+	return -1
+}