Function parseUpdateDiff

sdk/src/tools/apply-patch.ts:349–414

(
  lines: string[],
  input: string,
)

}

function parseUpdateDiff(
  lines: string[],
  input: string,
): { chunks: Chunk[]; fuzz: number } {
  const parser: ParserState = {
    lines: [...lines, END_PATCH],
    index: 0,
    fuzz: 0,
  }

  const inputLines = input.split('\n')
  const chunks: Chunk[] = []
  let cursor = 0

  while (!isDone(parser, END_SECTION_MARKERS)) {
    const current = parser.lines[parser.index]
    const line = typeof current === 'string' ? current : ''

    let anchor = ''
    const hasBareHeader = line === '@@'
    const hasWrappedHeader = isWrappedAtHeader(line)
    const hasAnchorHeader = line.startsWith('@@ ') && !hasWrappedHeader
    const hasAnyHeader = hasBareHeader || hasWrappedHeader || hasAnchorHeader

    if (hasAnchorHeader) {
      anchor = line.slice(3)
      parser.index += 1
    } else if (hasBareHeader || hasWrappedHeader) {
      parser.index += 1
    }

    if (!(hasAnyHeader || cursor === 0)) {
      throw new Error(`Invalid Line:\n${parser.lines[parser.index]}`)
    }

    if (anchor.trim()) {
      cursor = advanceCursorToAnchor(anchor, inputLines, cursor, parser)
    }

    const { nextContext, sectionChunks, endIndex, eof } = readSection(
      parser.lines,
      parser.index,
    )

    const { newIndex, fuzz } = findContext(inputLines, nextContext, cursor, eof)

    if (newIndex === -1) {
      const nextContextText = nextContext.join('\n')
      if (eof) {
        throw new Error(`Invalid EOF Context ${cursor}:\n${nextContextText}`)
      }

      throw new Error(`Invalid Context ${cursor}:\n${nextContextText}`)
    }

    parser.fuzz += fuzz
    for (const chunk of sectionChunks) {
      chunks.push({ ...chunk, origIndex: chunk.origIndex + newIndex })