Parameterised tests for Jest that enable running the same test multiple times with different data sets using arrays or tagged template literals
85
Mock implementation (mockImplementation, mockImplementationOnce)
Uses jest.fn()
0%
100%
Uses mockImplementation
0%
100%
Uses mockImplementationOnce
0%
100%
Mock return values
100%
100%
Mock error scenarios
100%
100%
Verifies mock calls
0%
100%
Lifecycle hooks (beforeAll, beforeEach, afterEach, afterAll)
beforeAll hook
100%
100%
beforeEach hook
100%
100%
afterEach hook
50%
100%
afterAll hook
100%
100%
Module mocker with metadata tracking
Uses jest.mock()
100%
100%
Accesses mocked module
100%
100%
Tracks call arguments
100%
100%
Checks call count
100%
100%
Accesses call history
100%
100%
Clears mock state
100%
100%
Snapshot property matchers
Uses toMatchSnapshot
0%
100%
Property matcher object
0%
100%
expect.any() matchers
0%
100%
Simple property matching
0%
100%
Nested property matching
0%
100%
Test coverage
100%
100%
Test timeout configuration
Default timeout usage
53%
100%
Per-test timeout parameter
100%
100%
Extended timeout configuration
100%
100%
Timeout failure test
100%
50%
Async test handling
100%
100%
Module mocking (jest.mock(), jest.unmock())
jest.mock() usage
0%
0%
Mock implementations
100%
100%
Failure scenario mocking
100%
100%
Mock verification
66%
100%
jest.unmock() usage
0%
0%
Mock cleanup
100%
80%
Mock return value configuration (mockReturnValue, mockResolvedValue, mockRejectedValue)
mockReturnValue usage
100%
100%
mockResolvedValue usage
100%
100%
mockRejectedValue usage
100%
100%
Test structure
100%
100%
Mock function creation (jest.fn())
Mock creation
100%
100%
Call verification
100%
100%
Argument verification
100%
100%
Negative assertions
100%
100%
Test completeness
100%
100%
Source map preservation
Transformer interface implementation
100%
100%
TypeScript compilation
100%
100%
Source map generation
100%
100%
Source map preservation
100%
100%
Jest configuration
100%
100%
Cache key implementation
100%
100%
Equality matchers (toBe, toEqual, toStrictEqual)
toBe for primitives
100%
0%
toEqual for objects
100%
0%
toBe fails reference
100%
0%
toEqual for arrays
100%
0%
toEqual for nested
100%
0%
toStrictEqual vs toEqual
100%
0%
Install with Tessl CLI
npx tessl i tessl/npm-jest-eachTable of Contents