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- # Disallow using `expect` outside of `it` or `test` blocks (`no-standalone-expect`)
-
- Prevents `expect` statements outside of a `test` or `it` block. An `expect`
- within a helper function (but outside of a `test` or `it` block) will not
- trigger this rule.
-
- ## Rule Details
-
- This rule aims to eliminate `expect` statements that will not be executed. An
- `expect` inside of a `describe` block but outside of a `test` or `it` block or
- outside of a `describe` will not execute and therefore will trigger this rule.
- It is viable, however, to have an `expect` in a helper function that is called
- from within a `test` or `it` block so `expect` statements in a function will not
- trigger this rule.
-
- Statements like `expect.hasAssertions()` will NOT trigger this rule since these
- calls will execute if they are not in a test block.
-
- Examples of **incorrect** code for this rule:
-
- ```js
- // in describe
- describe('a test', () => {
- expect(1).toBe(1);
- });
-
- // below other tests
- describe('a test', () => {
- it('an it', () => {
- expect(1).toBe(1);
- });
-
- expect(1).toBe(1);
- });
- ```
-
- Examples of **correct** code for this rule:
-
- ```js
- // in it block
- describe('a test', () => {
- it('an it', () => {
- expect(1).toBe(1);
- });
- });
-
- // in helper function
- describe('a test', () => {
- const helper = () => {
- expect(1).toBe(1);
- };
-
- it('an it', () => {
- helper();
- });
- });
-
- describe('a test', () => {
- expect.hasAssertions(1);
- });
- ```
-
- \*Note that this rule will not trigger if the helper function is never used even
- thought the `expect` will not execute. Rely on a rule like no-unused-vars for
- this case.
-
- ### Options
-
- #### `additionalTestBlockFunctions`
-
- This array can be used to specify the names of functions that should also be
- treated as test blocks:
-
- ```json
- {
- "rules": {
- "jest/no-standalone-expect": [
- "error",
- { "additionalTestBlockFunctions": ["each.test"] }
- ]
- }
- }
- ```
-
- The following is _correct_ when using the above configuration:
-
- ```js
- each([
- [1, 1, 2],
- [1, 2, 3],
- [2, 1, 3],
- ]).test('returns the result of adding %d to %d', (a, b, expected) => {
- expect(a + b).toBe(expected);
- });
- ```
-
- ## When Not To Use It
-
- Don't use this rule on non-jest test files.
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