Method diff

packages/shell/src/filesystem.ts:1370–1388

(pathA: string, pathB: string)

  // ── Diff ───────────────────────────────────────────────────────

  async diff(pathA: string, pathB: string): Promise<string> {
    const contentA = await this.readFile(pathA);
    if (contentA === null) throw new Error(`ENOENT: no such file: ${pathA}`);
    const contentB = await this.readFile(pathB);
    if (contentB === null) throw new Error(`ENOENT: no such file: ${pathB}`);
    const linesA = contentA.split("\n").length;
    const linesB = contentB.split("\n").length;
    if (linesA > MAX_DIFF_LINES || linesB > MAX_DIFF_LINES) {
      throw new Error(
        `EFBIG: files too large for diff (max ${MAX_DIFF_LINES} lines)`
      );
    }
    return unifiedDiff(
      contentA,
      contentB,
      normalizePath(pathA),
      normalizePath(pathB)
    );
  }

  async diffContent(path: string, newContent: string): Promise<string> {
    const existing = await this.readFile(path);