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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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