| 225 | ) |
| 226 | |
| 227 | func colorDiffLines(w io.Writer, r io.Reader) error { |
| 228 | diffLines := bufio.NewReaderSize(r, lineBufferSize) |
| 229 | wasPrefix := false |
| 230 | needsReset := false |
| 231 | |
| 232 | for { |
| 233 | diffLine, isPrefix, err := diffLines.ReadLine() |
| 234 | if err != nil { |
| 235 | if errors.Is(err, io.EOF) { |
| 236 | break |
| 237 | } |
| 238 | return fmt.Errorf("error reading pull request diff: %w", err) |
| 239 | } |
| 240 | |
| 241 | var color []byte |
| 242 | if !wasPrefix { |
| 243 | if isHeaderLine(diffLine) { |
| 244 | color = colorHeader |
| 245 | } else if isAdditionLine(diffLine) { |
| 246 | color = colorAddition |
| 247 | } else if isRemovalLine(diffLine) { |
| 248 | color = colorRemoval |
| 249 | } |
| 250 | } |
| 251 | |
| 252 | if color != nil { |
| 253 | if _, err := w.Write(color); err != nil { |
| 254 | return err |
| 255 | } |
| 256 | needsReset = true |
| 257 | } |
| 258 | |
| 259 | if _, err := w.Write(diffLine); err != nil { |
| 260 | return err |
| 261 | } |
| 262 | |
| 263 | if !isPrefix { |
| 264 | if needsReset { |
| 265 | if _, err := w.Write(colorReset); err != nil { |
| 266 | return err |
| 267 | } |
| 268 | needsReset = false |
| 269 | } |
| 270 | if _, err := w.Write([]byte{'\n'}); err != nil { |
| 271 | return err |
| 272 | } |
| 273 | } |
| 274 | wasPrefix = isPrefix |
| 275 | } |
| 276 | return nil |
| 277 | } |
| 278 | |
| 279 | var diffHeaderPrefixes = []string{"+++", "---", "diff", "index"} |
| 280 | |