| 11 | ) |
| 12 | |
| 13 | func TestTryLock(t *testing.T) { |
| 14 | tests := []struct { |
| 15 | name string |
| 16 | setup func(t *testing.T) string // returns lock path |
| 17 | wantErr error |
| 18 | verify func(t *testing.T, f *os.File) |
| 19 | }{ |
| 20 | { |
| 21 | name: "acquires lock and returns writable file handle", |
| 22 | setup: func(t *testing.T) string { |
| 23 | return filepath.Join(t.TempDir(), "test.lock") |
| 24 | }, |
| 25 | verify: func(t *testing.T, f *os.File) { |
| 26 | t.Helper() |
| 27 | _, err := f.WriteString("hello") |
| 28 | require.NoError(t, err) |
| 29 | _, err = f.Seek(0, 0) |
| 30 | require.NoError(t, err) |
| 31 | buf := make([]byte, 5) |
| 32 | n, err := f.Read(buf) |
| 33 | assert.NoError(t, err) |
| 34 | assert.Equal(t, "hello", string(buf[:n])) |
| 35 | }, |
| 36 | }, |
| 37 | { |
| 38 | name: "creates lock file if it does not exist", |
| 39 | setup: func(t *testing.T) string { |
| 40 | dir := filepath.Join(t.TempDir(), "subdir") |
| 41 | require.NoError(t, os.MkdirAll(dir, 0o755)) |
| 42 | return filepath.Join(dir, "new.lock") |
| 43 | }, |
| 44 | verify: func(t *testing.T, f *os.File) { |
| 45 | t.Helper() |
| 46 | _, err := os.Stat(f.Name()) |
| 47 | assert.NoError(t, err) |
| 48 | }, |
| 49 | }, |
| 50 | { |
| 51 | name: "second lock on same path returns ErrLocked", |
| 52 | setup: func(t *testing.T) string { |
| 53 | lockPath := filepath.Join(t.TempDir(), "contended.lock") |
| 54 | _, unlock, err := flock.TryLock(lockPath) |
| 55 | require.NoError(t, err) |
| 56 | t.Cleanup(unlock) |
| 57 | return lockPath |
| 58 | }, |
| 59 | wantErr: flock.ErrLocked, |
| 60 | }, |
| 61 | { |
| 62 | name: "lock succeeds after unlock", |
| 63 | setup: func(t *testing.T) string { |
| 64 | lockPath := filepath.Join(t.TempDir(), "reuse.lock") |
| 65 | _, unlock, err := flock.TryLock(lockPath) |
| 66 | require.NoError(t, err) |
| 67 | unlock() |
| 68 | return lockPath |
| 69 | }, |
| 70 | }, |