Namespace: matchers

matchers

Methods

nothing()

expect nothing explicitly.

Example

expect().nothing();

toBe(expected)

expect the actual value to be === to the expected value.

Parameters:

Name	Type	Description
expected	Object	The expected value to compare against.

Example

expect(thing).toBe(realThing);

toBeCloseTo(expected, precisionopt)

expect the actual value to be within a specified precision of the expected value.

Parameters:

Name	Type	Attributes	Default	Description
expected	Object			The expected value to compare against.
precision	Number	<optional>	2	The number of decimal points to check.

Example

expect(number).toBeCloseTo(42.2, 3);

toBeDefined()

expect the actual value to be defined. (Not undefined)

Example

expect(result).toBeDefined();

toBeFalsy()

expect the actual value to be falsy

Example

expect(result).toBeFalsy();

toBeGreaterThan(expected)

expect the actual value to be greater than the expected value.

Parameters:

Name	Type	Description
expected	Number	The value to compare against.

Example

expect(result).toBeGreaterThan(3);

toBeGreaterThanOrEqual(expected)

expect the actual value to be greater than or equal to the expected value.

Parameters:

Name	Type	Description
expected	Number	The expected value to compare against.

Example

expect(result).toBeGreaterThanOrEqual(25);

toBeLessThan(expected)

expect the actual value to be less than the expected value.

Parameters:

Name	Type	Description
expected	Number	The expected value to compare against.

Example

expect(result).toBeLessThan(0);

toBeLessThanOrEqual(expected)

expect the actual value to be less than or equal to the expected value.

Parameters:

Name	Type	Description
expected	Number	The expected value to compare against.

Example

expect(result).toBeLessThanOrEqual(123);

toBeNaN()

expect the actual value to be NaN (Not a Number).

Example

expect(thing).toBeNaN();

toBeNegativeInfinity()

expect the actual value to be -Infinity (-infinity).

Example

expect(thing).toBeNegativeInfinity();

toBeNull()

expect the actual value to be null.

Example

expect(result).toBeNull();

toBePositiveInfinity()

expect the actual value to be Infinity (infinity).

Example

expect(thing).toBePositiveInfinity();

toBeTruthy()

expect the actual value to be truthy.

Example

expect(thing).toBeTruthy();

toBeUndefined()

expect the actual value to be undefined.

Example

expect(result).toBeUndefined():

toContain(expected)

expect the actual value to contain a specific value.

Parameters:

Name	Type	Description
expected	Object	The value to look for.

Example

expect(array).toContain(anElement);
expect(string).toContain(substring);

toEqual(expected)

expect the actual value to be equal to the expected, using deep equality comparison.

Parameters:

Name	Type	Description
expected	Object	Expected value

Example

expect(bigObject).toEqual({"foo": ['bar', 'baz']});

toHaveBeenCalled()

expect the actual (a Spy) to have been called.

Example

expect(mySpy).toHaveBeenCalled();
expect(mySpy).not.toHaveBeenCalled();

toHaveBeenCalledBefore(expected)

expect the actual value (a Spy) to have been called before another Spy.

Parameters:

Name	Type	Description
expected	Spy	Spy that should have been called after the actual Spy.

Example

expect(mySpy).toHaveBeenCalledBefore(otherSpy);

toHaveBeenCalledTimes(expected)

expect the actual (a Spy) to have been called the specified number of times.

Parameters:

Name	Type	Description
expected	Number	The number of invocations to look for.

Example

expect(mySpy).toHaveBeenCalledTimes(3);

toHaveBeenCalledWith()

expect the actual (a Spy) to have been called with particular arguments at least once.

Parameters:

Type	Attributes	Description
Object	<repeatable>	The arguments to look for

Example

expect(mySpy).toHaveBeenCalledWith('foo', 'bar', 2);

toHaveClass(expected)

expect the actual value to be a DOM element that has the expected class

Parameters:

Name	Type	Description
expected	Object	The class name to test for

Example

var el = document.createElement('div');
el.className = 'foo bar baz';
expect(el).toHaveClass('bar');

toMatch(expected)

expect the actual value to match a regular expression

Parameters:

Name	Type	Description
expected	RegExp | String	Value to look for in the string.

Example

expect("my string").toMatch(/string$/);
expect("other string").toMatch("her");

toThrow(expectedopt)

expect a function to throw something.

Parameters:

Name	Type	Attributes	Description
expected	Object	<optional>	Value that should be thrown. If not provided, simply the fact that something was thrown will be checked.

Example

expect(function() { return 'things'; }).toThrow('foo');
expect(function() { return 'stuff'; }).toThrow();

toThrowError(expectedopt, messageopt)

expect a function to throw an Error.

Parameters:

Name	Type	Attributes	Description
expected	Error	<optional>	Error constructor the object that was thrown needs to be an instance of. If not provided, Error will be used.
message	RegExp | String	<optional>	The message that should be set on the thrown Error

Example

expect(function() { return 'things'; }).toThrowError(MyCustomError, 'message');
expect(function() { return 'things'; }).toThrowError(MyCustomError, /bar/);
expect(function() { return 'stuff'; }).toThrowError(MyCustomError);
expect(function() { return 'other'; }).toThrowError(/foo/);
expect(function() { return 'other'; }).toThrowError();

toThrowMatching(predicate)

expect a function to throw something matching a predicate.

Parameters:

Name	Type	Description
predicate	function	A function that takes the thrown exception as its parameter and returns true if it matches.

Example

expect(function() { throw new Error('nope'); }).toThrowMatching(function(thrown) { return thrown.message === 'nope'; });