feat: new rule await-async-utils #69
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,72 @@ | ||
| # Enforce async utils to be awaited properly (await-async-utils) | ||
|
|
||
| Ensure that promises returned by async utils are handled properly. | ||
|
|
||
| ## Rule Details | ||
|
|
||
| Testing library provides several utilities for dealing with asynchronous code. These are useful to wait for an element until certain criteria or situation happens. The available async utils are: | ||
|
|
||
| - `wait` | ||
| - `waitForElement` | ||
| - `waitForDomChange` | ||
| - `waitForElementToBeRemoved` | ||
|
|
||
| This rule aims to prevent users from forgetting to handle the returned promise from those async utils, which could lead to unexpected errors in the tests execution. The promises can be handled by using either `await` operator or `then` method. | ||
|
|
||
| Examples of **incorrect** code for this rule: | ||
|
|
||
| ```js | ||
| test('something incorrectly', async () => { | ||
| // ... | ||
| wait(() => getByLabelText('email')); | ||
|
|
||
| const [usernameElement, passwordElement] = waitForElement( | ||
| () => [ | ||
| getByLabelText(container, 'username'), | ||
| getByLabelText(container, 'password'), | ||
| ], | ||
| { container } | ||
| ); | ||
|
|
||
| waitForDomChange(() => { | ||
| return { container }; | ||
| }); | ||
|
|
||
| waitForElementToBeRemoved(() => document.querySelector('div.getOuttaHere')); | ||
| // ... | ||
| }); | ||
| ``` | ||
|
|
||
| Examples of **correct** code for this rule: | ||
|
|
||
| ```js | ||
| test('something correctly', async () => { | ||
| // ... | ||
| // `await` operator is correct | ||
| await wait(() => getByLabelText('email')); | ||
|
|
||
| const [usernameElement, passwordElement] = await waitForElement( | ||
| () => [ | ||
| getByLabelText(container, 'username'), | ||
| getByLabelText(container, 'password'), | ||
| ], | ||
| { container } | ||
| ); | ||
|
|
||
| // `then` chained method is correct | ||
| waitForDomChange(() => { | ||
| return { container }; | ||
| }) | ||
| .then(() => console.log('DOM changed!')) | ||
| .catch(err => console.log(`Error you need to deal with: ${err}`)); | ||
|
|
||
| // return the promise within a function is correct too! | ||
| const makeCustomWait = () => | ||
| waitForElementToBeRemoved(() => document.querySelector('div.getOuttaHere')); | ||
| // ... | ||
| }); | ||
| ``` | ||
|
|
||
| ## Further Reading | ||
|
|
||
| - [Async Utilities](https://testing-library.com/docs/dom-testing-library/api-async) |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,103 @@ | ||
| 'use strict'; | ||
|
There was a problem hiding this comment. This rule implementation is almost the same as |
||
|
|
||
| const { getDocsUrl, ASYNC_UTILS } = require('../utils'); | ||
|
|
||
| const VALID_PARENTS = [ | ||
| 'AwaitExpression', | ||
| 'ArrowFunctionExpression', | ||
| 'ReturnStatement', | ||
| ]; | ||
|
|
||
| const ASYNC_UTILS_REGEXP = new RegExp(`^(${ASYNC_UTILS.join('|')})$`); | ||
|
|
||
| module.exports = { | ||
| meta: { | ||
| type: 'problem', | ||
| docs: { | ||
| description: 'Enforce async utils to be awaited properly', | ||
| category: 'Best Practices', | ||
| recommended: true, | ||
| url: getDocsUrl('await-async-utils'), | ||
| }, | ||
| messages: { | ||
| awaitAsyncUtil: 'Promise returned from `{{ name }}` must be handled', | ||
| }, | ||
| fixable: null, | ||
| schema: [], | ||
| }, | ||
|
|
||
| create: function(context) { | ||
| const testingLibraryUtilUsage = []; | ||
| return { | ||
| [`CallExpression > Identifier[name=${ASYNC_UTILS_REGEXP}]`](node) { | ||
| if (!isAwaited(node.parent.parent) && !isPromiseResolved(node)) { | ||
| testingLibraryUtilUsage.push(node); | ||
| } | ||
| }, | ||
| 'Program:exit'() { | ||
|
There was a problem hiding this comment. Ah interesting, I didn’t know about this There was a problem hiding this comment. Me either! I learnt about it thanks to @thomlom, you can find more info here |
||
| testingLibraryUtilUsage.forEach(node => { | ||
| const variableDeclaratorParent = node.parent.parent; | ||
|
|
||
| const references = | ||
| (variableDeclaratorParent.type === 'VariableDeclarator' && | ||
| context | ||
| .getDeclaredVariables(variableDeclaratorParent)[0] | ||
| .references.slice(1)) || | ||
| []; | ||
|
|
||
| if ( | ||
| references && | ||
| references.length === 0 && | ||
| !isAwaited(node.parent.parent) && | ||
| !isPromiseResolved(node) | ||
| ) { | ||
| context.report({ | ||
| node, | ||
| messageId: 'awaitAsyncUtil', | ||
| data: { | ||
| name: node.name, | ||
| }, | ||
| }); | ||
| } else { | ||
| for (const reference of references) { | ||
| const referenceNode = reference.identifier; | ||
| if ( | ||
| !isAwaited(referenceNode.parent) && | ||
| !isPromiseResolved(referenceNode) | ||
| ) { | ||
| context.report({ | ||
| node, | ||
| messageId: 'awaitAsyncUtil', | ||
| data: { | ||
| name: node.name, | ||
| }, | ||
| }); | ||
|
|
||
| break; | ||
| } | ||
| } | ||
| } | ||
| }); | ||
| }, | ||
| }; | ||
| }, | ||
| }; | ||
|
|
||
| function isAwaited(node) { | ||
| return VALID_PARENTS.includes(node.type); | ||
| } | ||
|
|
||
| function isPromiseResolved(node) { | ||
| const parent = node.parent; | ||
|
|
||
| const hasAThenProperty = node => | ||
|
There was a problem hiding this comment. Does this need to be declared inside the There was a problem hiding this comment. Not really, let me move this outside. |
||
| node.type === 'MemberExpression' && node.property.name === 'then'; | ||
|
|
||
| // wait(...).then(...) | ||
| if (parent.type === 'CallExpression') { | ||
| return hasAThenProperty(parent.parent); | ||
| } | ||
|
|
||
| // promise.then(...) | ||
| return hasAThenProperty(parent); | ||
| } | ||
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Oops, something went wrong.
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
I removed this by mistake in that PR trying to fix the badges.