codemod-missing-await-act v0.1.0

codemod-missing-await-act

Adds missing await to act calls or methods that like contain an act call using jscodeshift. We all track usage of these methods throughout the file. For example, given

import { act } from "react-dom/test-utils";

function focus(element) {
	act(() => {
		element.focus();
	});
}

test("focusing", () => {
	const { container } = render("<button />");

	focus(container);
});

will add an await to act and also add await to focus since focus is now an async method. The end result will be

import { act } from "react-dom/test-utils";

async function focus(element) {
	await act(() => {
		element.focus();
	});
}

test("focusing", async () => {
	const { container } = await render("<button />");

	await focus(container);
});

The following methods will be awaited when the codemod is applied:

• from react:
  • unstable_act
• from react-dom/test-utils:
  • act
• from react-test-renderer:
  • act
• from @testing-library/react:
  • act
  • cleanup
  • fireEvent
  • fireEvent.*
  • render
  • renderHook

Right now we assume that any call to rerender and unmount should be awaited. These are all names of methods from React Testing Library.´

Getting started

$ npx codemod-missing-await-act ./src
Processing 4 files...
All done.
Results:
0 errors
3 unmodified
0 skipped
1 ok
Time elapsed: 0.428seconds

Usage

$ npx codemod-missing-await-act

codemod-missing-await-act <paths...>

Positionals:
  paths                                               [string] [required]

Options:
  --version         Show version number                         [boolean]
  --help            Show help                                   [boolean]
  --dry                                        [boolean] [default: false]
  --ignore-pattern               [string] [default: "**/node_modules/**"]
  --verbose                                    [boolean] [default: false]

Examples:
  codemod-missing-await-act ./              Ignores `node_modules` and
  --ignore-pattern                      `build` folders
  "**/{node_modules,build}/**"

Limitations

Forces call expressions to be awaited

const acting = act(scope);
await anotherPromise;
await acting;

will add await to the act call.

This codemod is targetted at act calls. They're not allowed to be interleaved anyway so the original code was already problematic since it could also contain an act call. I don't think this is common in practice (TODO: check if we use this pattern).

async class methods are not propagated

We don't track references to class methods. Only references to (arrow-) function declarations or expressions are tracked.

class MyTestUtils {
	render() {
		act(scope);
	}
}

const utils = new MyTestUtils();

utils.render();

will be transformed to

class MyTestUtils {
	async render() {
		await act(scope);
	}
}

const utils = new MyTestUtils();

// no `await` added
utils.render();

Supported platforms

The following list contains officially supported runtimes. Please file an issue for runtimes that are not included in this list.

• Node.js 14.x || 16.x || 18.x || 19.x || 20.x