Function parseOneHunk

src/core/tools/apply-patch/parser.ts:201–288

* Parse a single hunk (file operation) from lines. * Returns the parsed hunk and number of lines consumed.

(lines: string[], lineNumber: number)

 * Returns the parsed hunk and number of lines consumed.
 */
function parseOneHunk(lines: string[], lineNumber: number): { hunk: Hunk; linesConsumed: number } {
	const firstLine = lines[0]?.trim()

	// Add File
	if (firstLine?.startsWith(ADD_FILE_MARKER)) {
		const path = firstLine.substring(ADD_FILE_MARKER.length)
		let contents = ""
		let parsedLines = 1

		for (let i = 1; i < lines.length; i++) {
			const line = lines[i]
			if (line?.startsWith("+")) {
				contents += line.substring(1) + "\n"
				parsedLines++
			} else {
				break
			}
		}

		return {
			hunk: { type: "AddFile", path, contents },
			linesConsumed: parsedLines,
		}
	}

	// Delete File
	if (firstLine?.startsWith(DELETE_FILE_MARKER)) {
		const path = firstLine.substring(DELETE_FILE_MARKER.length)
		return {
			hunk: { type: "DeleteFile", path },
			linesConsumed: 1,
		}
	}

	// Update File
	if (firstLine?.startsWith(UPDATE_FILE_MARKER)) {
		const path = firstLine.substring(UPDATE_FILE_MARKER.length)
		let remainingLines = lines.slice(1)
		let parsedLines = 1

		// Check for optional Move to line
		let movePath: string | null = null
		if (remainingLines[0]?.startsWith(MOVE_TO_MARKER)) {
			movePath = remainingLines[0].substring(MOVE_TO_MARKER.length)
			remainingLines = remainingLines.slice(1)
			parsedLines++
		}

		const chunks: UpdateFileChunk[] = []

		while (remainingLines.length > 0) {
			// Skip blank lines between chunks
			if (remainingLines[0]?.trim() === "") {
				parsedLines++
				remainingLines = remainingLines.slice(1)
				continue
			}