| 245 | ) |
| 246 | |
| 247 | func colorDiffLines(w io.Writer, r io.Reader) error { |
| 248 | diffLines := bufio.NewReaderSize(r, lineBufferSize) |
| 249 | wasPrefix := false |
| 250 | needsReset := false |
| 251 | |
| 252 | for { |
| 253 | diffLine, isPrefix, err := diffLines.ReadLine() |
| 254 | if err != nil { |
| 255 | if errors.Is(err, io.EOF) { |
| 256 | break |
| 257 | } |
| 258 | return fmt.Errorf("error reading pull request diff: %w", err) |
| 259 | } |
| 260 | |
| 261 | var color []byte |
| 262 | if !wasPrefix { |
| 263 | if isHeaderLine(diffLine) { |
| 264 | color = colorHeader |
| 265 | } else if isAdditionLine(diffLine) { |
| 266 | color = colorAddition |
| 267 | } else if isRemovalLine(diffLine) { |
| 268 | color = colorRemoval |
| 269 | } |
| 270 | } |
| 271 | |
| 272 | if color != nil { |
| 273 | if _, err := w.Write(color); err != nil { |
| 274 | return err |
| 275 | } |
| 276 | needsReset = true |
| 277 | } |
| 278 | |
| 279 | if _, err := w.Write(diffLine); err != nil { |
| 280 | return err |
| 281 | } |
| 282 | |
| 283 | if !isPrefix { |
| 284 | if needsReset { |
| 285 | if _, err := w.Write(colorReset); err != nil { |
| 286 | return err |
| 287 | } |
| 288 | needsReset = false |
| 289 | } |
| 290 | if _, err := w.Write([]byte{'\n'}); err != nil { |
| 291 | return err |
| 292 | } |
| 293 | } |
| 294 | wasPrefix = isPrefix |
| 295 | } |
| 296 | return nil |
| 297 | } |
| 298 | |
| 299 | var diffHeaderPrefixes = []string{"+++", "---", "diff", "index"} |
| 300 | |