Jest Testing Cheat Sheet

Basic Equality

.toBe(value)

===

.toEqual(value)

Asserts equal using deep equal comparison

Spies

.toHaveBeenCalled()

Asserts mock function was called

.toHaveBeenCalledTimes(n)

Asserts mock function was called

times

.toHaveBeenCalledWith(arg1, arg2, ...)

Asserts mock function was called with provided arguments

.toHaveBeenLastCalledWith(arg1, arg2, ...)

Asserts mock function was called with provided arguments on last invocation

Booleanish

.toBeTruthy()

Asserts value is true in a boolean context

.toBeFalsy()

Asserts value is false in a boolean context

Numeric Comparisons

.toBeGreaterThan(number)

.toBeGreaterThanOrEqual(number)

>==

.toBeLessThan(number)

.toBeLessThanOrEqual(number)

<==

 .toBeCloseTo(number, numDigits)

Asserts number is close to another at given precision

Type Assertions

.toBeInstanceOf(Class)

Containment

.toContain(item)

Asserts an array contains item using

===

.toContainEqual(item)

Asserts an array contains item using deep equal comparison

.toMatchObject(object)

.toMatch(regexpOrString)

Errors

.toThrow(error)

Snapshot Testing

.toMatchSnapshot(optionalString)

.toThrowErrorMatchingSnapshot()

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Jest Testing Cheat Sheet (DRAFT) by slavsquatch