| 1 | package replication |
| 2 | |
| 3 | import ( |
| 4 | "errors" |
| 5 | "io" |
| 6 | "os" |
| 7 | "path/filepath" |
| 8 | "testing" |
| 9 | ) |
| 10 | |
| 11 | func TestWriteArtifactFailurePreservesPreviousFile(t *testing.T) { |
| 12 | dir := t.TempDir() |
| 13 | path := filepath.Join(dir, "relay.json" ) |
| 14 | const previous = "previous artifact\n" |
| 15 | if err := os.WriteFile(path, []byte(previous), 0o600); err != nil { |
| 16 | t.Fatal(err) |
| 17 | } |
| 18 | wantErr := errors.New("generation failed" ) |
| 19 | if err := writeArtifact(path, func(w io.Writer) error { |
| 20 | if _, err := w.Write([]byte("partial replacement" )); err != nil { |
| 21 | return err |
| 22 | } |
| 23 | return wantErr |
| 24 | }); !errors.Is(err, wantErr) { |
| 25 | t.Fatalf("writeArtifact error = %v, want %v" , err, wantErr) |
| 26 | } |
| 27 | got, err := os.ReadFile(path) |
| 28 | if err != nil { |
| 29 | t.Fatal(err) |
| 30 | } |
| 31 | if string(got) != previous { |
| 32 | t.Fatalf("previous artifact changed: %q" , got) |
| 33 | } |
| 34 | entries, err := os.ReadDir(dir) |
| 35 | if err != nil { |
| 36 | t.Fatal(err) |
| 37 | } |
| 38 | if len(entries) != 1 || entries[0].Name() != "relay.json" { |
| 39 | t.Fatalf("staging file left behind: %#v" , entries) |
| 40 | } |
| 41 | } |