Function buildDiff

app/src/lib/git/diff.ts:811–859

(
  buffer: Buffer,
  repository: Repository,
  file: FileChange,
  newestCommitish: string,
  oldestCommitish: string,
  lineEndingsChange?: LineEndingsChange
)

}

async function buildDiff(
  buffer: Buffer,
  repository: Repository,
  file: FileChange,
  newestCommitish: string,
  oldestCommitish: string,
  lineEndingsChange?: LineEndingsChange
): Promise<IDiff> {
  if (file.status.submoduleStatus !== undefined) {
    return buildSubmoduleDiff(
      buffer,
      repository,
      file,
      file.status.submoduleStatus
    )
  }

  if (!isValidBuffer(buffer)) {
    // the buffer's diff is too large to be renderable in the UI
    return { kind: DiffType.Unrenderable }
  }

  const diff = diffFromRawDiffOutput(buffer)

  if (isBufferTooLarge(buffer) || isDiffTooLarge(diff)) {
    // we don't want to render by default
    // but we keep it as an option by
    // passing in text and hunks
    const largeTextDiff: ILargeTextDiff = {
      kind: DiffType.LargeText,
      text: diff.contents,
      hunks: diff.hunks,
      lineEndingsChange,
      maxLineNumber: diff.maxLineNumber,
      hasHiddenBidiChars: diff.hasHiddenBidiChars,
    }

    return largeTextDiff
  }

  return convertDiff(
    repository,
    file,
    diff,
    newestCommitish,
    oldestCommitish,
    lineEndingsChange
  )
}

/**
 * Retrieve the binary contents of a blob from the object database