Function deriveNewContentsFromChunks

packages/opencode/src/patch/index.ts:307–340

(
  filePath: string,
  chunks: UpdateFileChunk[],
  originalText: string,
)

}

export function deriveNewContentsFromChunks(
  filePath: string,
  chunks: UpdateFileChunk[],
  originalText: string,
): ApplyPatchFileUpdate {
  const originalContent = Bom.split(originalText)

  let originalLines = originalContent.text.split("\n")

  // Drop trailing empty element for consistent line counting
  if (originalLines.length > 0 && originalLines[originalLines.length - 1] === "") {
    originalLines.pop()
  }

  const replacements = computeReplacements(originalLines, filePath, chunks)
  let newLines = applyReplacements(originalLines, replacements)

  // Ensure trailing newline
  if (newLines.length === 0 || newLines[newLines.length - 1] !== "") {
    newLines.push("")
  }

  const next = Bom.split(newLines.join("\n"))
  const newContent = next.text

  // Generate unified diff
  const unifiedDiff = generateUnifiedDiff(originalContent.text, newContent)

  return {
    unified_diff: unifiedDiff,
    content: newContent,
    bom: originalContent.bom || next.bom,
  }
}

function computeReplacements(
  originalLines: string[],