codemod-missing-await-act

Adds missing await to act calls or methods that contain an act call using jscodeshift. The codemod propagates these changes throughout the file. For example, given

import { act } from "react";

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";

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

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

	await focus(container);
});

Right now we assume that any call to rerender and unmount should be awaited.

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/**"]
  --import-config   A path to a JS file importing all methods whose calls should
                    be awaited.                                         [string]
  --verbose                                           [boolean] [default: false]

Examples:
  codemod-missing-await-act ./              Ignores `node_modules` and `build`
  --ignore-pattern                          folders
  "**/{node_modules,build}/**"
  codemod-missing-await-act ./              Adds await to to all calls of
  --import-confg                            methods imported in that file.
  ./missing-await-import-config.js

Custom import config

When a newly async function is exported, the codemod will not automatically update all references. However, the codemod summarizes at the end which files are impacted and will generate an import config that can be used to update the remaining references if these are imported via relative imports.

codemod-missing-await/config/default-import-config.json

{
	"$schema": "https://github.com/eps1lon/codemod-missing-await-act/tree/main/config/schema-latest.json",
	"version": 1,
	"imports": [
		{
			"sources": [
				"@testing-library/react",
				"@testing-library/react/pure",
				"@testing-library/react-native",
				"@testing-library/react-native/pure"
			],
			"specifiers": [
				"act",
				"cleanup",
				{ "imported": "fireEvent", "includeMemberCalls": true },
				"render",
				"renderHook"
			]
		},
		{
			"sources": "react",
			"specifiers": ["act", "unstable_act"]
		},
		{
			"sources": ["react-dom/test-utils", "react-test-renderer"],
			"specifiers": ["act"]
		}
	]
}

Type:

interface ImportConfig {
	version: number;
	imports: Array<{
		/**
		 * The module specifier.
		 */
		sources: string;
		/**
		 * The specifiers that should be awaited.
		 * `Array<string>` and `Array<{ imported: string>` are equivalent
		 */
		specifiers: Array<
			| string
			| {
					imported: string;
					/**
					 * If `true` all member calls of the imported specifier will be awaited.
					 * For example, `{ imported: 'fireEvent', includeMemberCalls: true }` will await `fireEvent()` as well as `fireEvent.mouseEnter(element)`, `fireEvent.click(element)` etc..
					 */
					includeMemberCalls?: boolean;
					/**
					 * If true, the imported specifier is assumed to be a factor for a newly
					 * async function.
					 * For example, in `export const makeRender = () => () => render(...)`
					 * we'd specify `{ imported: 'makeRender', asyncFunctionFactory: true }`Ï
					 */
					asyncFunctionFactory?: boolean;
			  }
		>;
	}>;
}

Latest JSON schema all versions

For example, when we transform this ~/src/utils.js file

export function hoverAndClick(element) {
	fireEvent.mouseEnter(element);
	fireEvent.click(element);
}

hoverAndClick will now be async. The codemod generates an import config that will look something like this

{
	"$schema": "",
	"imports": [
		{
			"sources": ["file:///Users/you/repo/src/utils.js"],
			"specifiers": ["hoverAndClick"]
		}
	]
}

You can then run the codemod again with the --import-config option.

The codemod will now also await hoverAndClick if utils.js is imported via a relative path.

import { render } from "@testing-library/react";
import { hoverAndClick } from "./utils";

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

	hoverAndClick(container);
});

will be transformed into

import { render } from "@testing-library/react";
import { hoverAndClick } from "./utils";

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

	await hoverAndClick(container);
});

You need to repeat this process until the codemod no longer prompts you at the end to update the import config.

If you use path aliases or modules with newly async exports are imported via package specifiers, you need to manually adjust the import config e.g.

 {
 	"$schema": "",
 	"imports": [
 		{
-			"sources": ["file:///Users/you/repo/src/utils.js"],
+			"sources": ["@my/module", "file:///Users/you/repo/src/utils.js"],
 			"specifiers": ["hoverAndClick"]
 		}
 	]
 }

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. act() calls are not allowed to overlap anyway so the original code was already problematic since acting could also contain an act call.

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 18.x || 20.x || 22.x || 23.x