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small-rules

Prefer Expect Assertions

SuggestionAuto-fixable
small-rules/prefer-expect-assertions

Enforce expect assertion guards in tests and prefer expect.assertions(n) over expect.hasAssertions() when the count is known.

Diagnostic Messages

assertionsRequiresNumberArgument
This argument should be a number
assertionsRequiresOneArgument
`expect.assertions` expects a single argument of type number
hasAssertionsTakesNoArguments
`expect.hasAssertions` expects no arguments
haveExpectAssertions
Every test should have either `expect.assertions(<number of assertions>)` or `expect.hasAssertions()` as its first expression
preferAssertionsCount
Use `expect.assertions({{count}})` instead of `expect.hasAssertions()` when the count is known
suggestAddingAssertions
Add `expect.assertions({{count}})`
suggestAddingHasAssertions
Add `expect.hasAssertions()`
wrongAssertionCount
Expected {{expected}} assertions, but test has {{actual}} expect calls

Configuration

This rule accepts one options object after the severity.

additionalAssertionFunctionsOptional

Additional assertion function names counted as test assertions.

Type
Array<string>
Default
additionalExpectCallNamesOptional

Additional expect-like call names counted when checking assertion counts.

Type
Array<string>
Default
onlyFunctionsWithAsyncKeywordOptional

Only require assertion guards for test callbacks marked async.

Type
boolean
Default
false
onlyFunctionsWithExpectInCallbackOptional

Only require assertion guards when expect is called inside a nested callback.

Type
boolean
Default
false
onlyFunctionsWithExpectInLoopOptional

Only require assertion guards when expect is called inside a loop.

Type
boolean
Default
false
{
  "jsPlugins": [
    "@pobammer-ts/small-rules"
  ],
  "rules": {
    "small-rules/prefer-expect-assertions": [
      "error",
      {
        "additionalAssertionFunctions": [],
        "additionalExpectCallNames": [],
        "onlyFunctionsWithAsyncKeyword": false,
        "onlyFunctionsWithExpectInCallback": false,
        "onlyFunctionsWithExpectInLoop": false
      }
    ]
  }
}

Examples

Prefer assertion count over hasAssertions
test('works', () => { expect.hasAssertions(); expect(value).toBe(1); });

After auto-fix

test('works', () => { expect.assertions(1); expect(value).toBe(1); });
Explicit assertion count
test('works', () => { expect.assertions(1); expect(value).toBe(1); });