Function applyPatch

src/apply-patch.ts:317–360

(root: string, patch: string)

}

export async function applyPatch(root: string, patch: string): Promise<ApplyPatchResult> {
  const actions = parsePatch(patch);
  const results: AppliedPatchFile[] = [];
  const patches: string[] = [];

  for (const action of actions) {
    if (action.kind === "add") {
      const absolute = await resolveConfinedPath(root, action.path);
      const original = await readOptionalTextFile(absolute, action.path);
      await writeTextFile(absolute, action.content, original?.mode);
      patches.push(unifiedFilePatch(action.path, action.path, original?.content ?? null, action.content));
      results.push({ path: action.path, operation: "add" });
      continue;
    }

    const absolute = await resolveConfinedPath(root, action.path);
    const file = await readRequiredTextFile(absolute, action.path);

    if (action.kind === "delete") {
      await rm(absolute);
      patches.push(unifiedFilePatch(action.path, action.path, file.content, null));
      results.push({ path: action.path, operation: "delete" });
      continue;
    }

    const updated = applyHunks(action.path, file.content, action.hunks);
    if (action.moveTo) {
      const destination = await resolveConfinedPath(root, action.moveTo);
      if (destination !== absolute) await readOptionalTextFile(destination, action.moveTo);
      await writeTextFile(destination, updated, file.mode);
      if (destination !== absolute) await rm(absolute);
      patches.push(unifiedFilePatch(action.path, action.moveTo, file.content, updated));
      results.push({ path: action.moveTo, previousPath: action.path, operation: "move" });
    } else {
      await writeTextFile(absolute, updated, file.mode);
      patches.push(unifiedFilePatch(action.path, action.path, file.content, updated));
      results.push({ path: action.path, operation: "update" });
    }
  }

  const unifiedPatch = patches.filter(Boolean).join("\n");
  const stats = countPatchStats(unifiedPatch);
  return { files: results, patch: unifiedPatch, ...stats };
}

async function readRequiredTextFile(absolute: string, displayPath: string): Promise<TextFile> {
  if (!(await fileExists(absolute))) throw patchError(`file does not exist: ${displayPath}`);