Equality & Comparison Assertions

These assertions test equality, identity, and value comparisons.

{unknown} to equal {any}

✏️ Aliases:

{unknown} to equal {any}
{unknown} to be {any}
{unknown} equals {any}
{unknown} is {any}
{unknown} is equal to {any}
{unknown} to strictly equal {any}
{unknown} is strictly equal to {any}

Success:

expect(42, 'to be', 42);
expect('hello', 'to equal', 'hello');
expect(true, 'is', true);
expect(null, 'is equal to', null);
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Failure:

expect(42, 'to be', '42');
// AssertionError: Expected 42 to be '42'
expect({}, 'to equal', {});
// AssertionError: Expected {} to equal {}
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Negation:

expect(42, 'not to be', '42');
expect({}, 'not to equal', {});
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{unknown} to deep equal {any}

✏️ Aliases:

{unknown} to deep equal {any}
{unknown} to deep equal {any}

Success:

expect({ a: 1, b: 2 }, 'to deep equal', { a: 1, b: 2 });
expect([1, 2, 3], 'to deeply equal', [1, 2, 3]);
expect({ nested: { value: 42 } }, 'to deep equal', { nested: { value: 42 } });
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Failure:

expect({ a: 1 }, 'to deep equal', { a: 1, b: 2 });
// AssertionError: Expected { a: 1 } to deep equal { a: 1, b: 2 }
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Negation:

expect({ a: 1 }, 'not to deep equal', { a: 1, b: 2 });
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{unknown} to be one of {array}

Success:

expect(2, 'to be one of', [1, 2, 3]);
expect('blue', 'to be one of', ['red', 'green', 'blue']);
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Failure:

expect(5, 'to be one of', [1, 2, 3]);
// AssertionError: Expected 5 to be one of [1, 2, 3]
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Negation:

expect(5, 'not to be one of', [1, 2, 3]);
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{unknown} to be an instance of {constructor}

✏️ Aliases:

{unknown} to be an instance of {constructor}
{unknown} to be a {constructor}
{unknown} to be an {constructor}

Success:

expect(new Date(), 'to be an instance of', Date);
expect([], 'to be a', Array);
expect('hello', 'to be an instance of', String); // Note: primitive strings work too
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Failure:

expect('hello', 'to be an instance of', Number);
// AssertionError: Expected 'hello' to be an instance of Number
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Negation:

expect('hello', 'not to be an instance of', Number);
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{unknown} to be a {intrinsic-type}

✏️ Aliases:

{unknown} to be a {intrinsic-type}
{unknown} to be an {intrinsic-type}
{unknown} to have type {intrinsic-type}

An intrinsic type is a case-insensitive string matching: string, number, boolean, bigint, symbol, undefined, object, function, null, Map, Set, WeakMap, WeakSet, WeakRef, Date, Error, Array, RegExp, Promise. This is a mashup of the result of typeof and constructor names for built-in types.

Success:

expect(new Date(), 'to be a', 'Date');
expect(new Error(), 'to be an', 'Error');
expect([], 'to be an', 'Array');
expect(1, 'to be a', 'number');
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Failure:

expect('hello', 'to be a', Number);
// AssertionError: Expected 'hello' to be a Number
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Negation:

expect('hello', 'not to be a', Number);
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