codex-agent-manager/internal/agents/writeback_test.go

package agents

import (
	"errors"
	"os"
	"path/filepath"
	"strings"
	"testing"
)

func TestValidateInvalidTOMLReturnsInvalidAndDoesNotWrite(t *testing.T) {
	store, target := writebackFixture(t, `name = "旧名称"`+"\n")

	got, err := store.ValidateDraft("backend", `name = "未闭合`+"\n")
	if err != nil {
		t.Fatalf("ValidateDraft returned error: %v", err)
	}
	if got.Valid {
		t.Fatalf("validation should be invalid: %#v", got)
	}
	if len(got.Errors) == 0 {
		t.Fatalf("expected validation errors: %#v", got)
	}
	assertFileContent(t, target, `name = "旧名称"`+"\n")
}

func TestValidateValidTOMLReturnsDiffAndCurrentHash(t *testing.T) {
	store, _ := writebackFixture(t, `name = "旧名称"`+"\ndescription = \"旧描述\"\n")

	got, err := store.ValidateDraft("backend", `name = "新名称"`+"\ndescription = \"旧描述\"\n")
	if err != nil {
		t.Fatalf("ValidateDraft returned error: %v", err)
	}
	if !got.Valid {
		t.Fatalf("validation should be valid: %#v", got)
	}
	if got.CurrentHash == "" {
		t.Fatalf("current hash must be returned: %#v", got)
	}
	if !strings.Contains(got.Diff, `-name = "旧名称"`) || !strings.Contains(got.Diff, `+name = "新名称"`) {
		t.Fatalf("diff does not show changed line: %q", got.Diff)
	}
	if len(got.FieldChanges) != 1 || got.FieldChanges[0].Field != "name" {
		t.Fatalf("unexpected field changes: %#v", got.FieldChanges)
	}
}

func TestWriteInvalidTOMLRejectsAndLeavesOriginal(t *testing.T) {
	store, target := writebackFixture(t, `name = "旧名称"`+"\n")
	validation, err := store.ValidateDraft("backend", `name = "新名称"`+"\n")
	if err != nil {
		t.Fatal(err)
	}

	_, err = store.WriteDraft("backend", `name = "未闭合`+"\n", validation.CurrentHash)
	if err == nil {
		t.Fatal("expected invalid TOML write to be rejected")
	}
	assertFileContent(t, target, `name = "旧名称"`+"\n")
}

func TestWriteExpectedHashMismatchRejectsAndLeavesOriginal(t *testing.T) {
	store, target := writebackFixture(t, `name = "旧名称"`+"\n")
	validation, err := store.ValidateDraft("backend", `name = "新名称"`+"\n")
	if err != nil {
		t.Fatal(err)
	}
	if err := os.WriteFile(target, []byte(`name = "用户已改"`+"\n"), 0o644); err != nil {
		t.Fatal(err)
	}

	_, err = store.WriteDraft("backend", `name = "新名称"`+"\n", validation.CurrentHash)
	if !errors.Is(err, ErrWriteConflict) {
		t.Fatalf("expected conflict error, got %v", err)
	}
	assertFileContent(t, target, `name = "用户已改"`+"\n")
}

func TestWriteSuccessCreatesBackupAndAtomicallyWrites(t *testing.T) {
	store, target := writebackFixture(t, `name = "旧名称"`+"\n")
	validation, err := store.ValidateDraft("backend", `name = "新名称"`+"\n")
	if err != nil {
		t.Fatal(err)
	}

	got, err := store.WriteDraft("backend", `name = "新名称"`+"\n", validation.CurrentHash)
	if err != nil {
		t.Fatalf("WriteDraft returned error: %v", err)
	}
	if got.Status != "written" || got.TargetPath != target || got.BackupPath == "" {
		t.Fatalf("unexpected write result: %#v", got)
	}
	assertFileContent(t, target, `name = "新名称"`+"\n")
	assertFileContent(t, got.BackupPath, `name = "旧名称"`+"\n")
}

func TestWriteRejectsUnsafeIDAndSymlinks(t *testing.T) {
	store, target := writebackFixture(t, `name = "旧名称"`+"\n")
	validation, err := store.ValidateDraft("backend", `name = "新名称"`+"\n")
	if err != nil {
		t.Fatal(err)
	}

	for _, id := range []string{"../backend", "nested/backend", "/tmp/backend", "backend.toml"} {
		t.Run("unsafe id "+id, func(t *testing.T) {
			if _, err := store.ValidateDraft(id, `name = "x"`+"\n"); err == nil {
				t.Fatal("expected unsafe validate id to be rejected")
			}
			if _, err := store.WriteDraft(id, `name = "x"`+"\n", validation.CurrentHash); err == nil {
				t.Fatal("expected unsafe write id to be rejected")
			}
		})
	}

	if err := os.Remove(target); err != nil {
		t.Fatal(err)
	}
	if err := os.Symlink("../config.toml", target); err != nil {
		t.Fatal(err)
	}
	if _, err := store.WriteDraft("backend", `name = "新名称"`+"\n", validation.CurrentHash); err == nil {
		t.Fatal("expected symlink leaf to be rejected")
	}

	root := t.TempDir()
	if err := os.WriteFile(filepath.Join(root, "config.toml"), []byte(`name = "secret"`), 0o600); err != nil {
		t.Fatal(err)
	}
	if err := os.Symlink(".", filepath.Join(root, "agents")); err != nil {
		t.Fatal(err)
	}
	symlinkedStore := Store{CodexHome: root}
	if _, err := symlinkedStore.WriteDraft("backend", `name = "x"`+"\n", validation.CurrentHash); err == nil {
		t.Fatal("expected symlinked agents directory to be rejected")
	}
}

func writebackFixture(t *testing.T, content string) (Store, string) {
	t.Helper()
	root := t.TempDir()
	agentsDir := filepath.Join(root, "agents")
	if err := os.MkdirAll(agentsDir, 0o755); err != nil {
		t.Fatal(err)
	}
	target := filepath.Join(agentsDir, "backend.toml")
	if err := os.WriteFile(target, []byte(content), 0o644); err != nil {
		t.Fatal(err)
	}
	return Store{CodexHome: root}, target
}

func assertFileContent(t *testing.T, path string, want string) {
	t.Helper()
	got, err := os.ReadFile(path)
	if err != nil {
		t.Fatal(err)
	}
	if string(got) != want {
		t.Fatalf("%s content = %q, want %q", path, string(got), want)
	}
}