Numeric Assertions

These assertions test numeric values, ranges, and mathematical relationships.

{unknown} to be a number

👉 See to be a number

{unknown} to be infinite

Success:

expect(Infinity, 'to be infinite');
expect(-Infinity, 'to be infinite');

Failure:

expect(42, 'to be infinite');
// AssertionError: Expected 42 to be infinite

Negation:

expect(42, 'not to be infinite');

{unknown} to be Infinity

Success:

expect(Infinity, 'to be Infinity');

Failure:

expect(-Infinity, 'to be Infinity');
// AssertionError: Expected -Infinity to be Infinity

Negation:

expect(-Infinity, 'not to be Infinity');

{unknown} to be -Infinity

Success:

expect(-Infinity, 'to be -Infinity');

Failure:

expect(Infinity, 'to be -Infinity');
// AssertionError: Expected Infinity to be -Infinity

Negation:

expect(Infinity, 'not to be -Infinity');

{unknown} to be positive

✏️ Aliases:

{unknown} to be positive
{unknown} to be a positive number

Success:

expect(42, 'to be positive');
expect(3.14, 'to be positive');

Failure:

expect(-5, 'to be positive');
// AssertionError: Expected -5 to be positive
expect(0, 'to be positive');

Negation:

expect(-5, 'not to be positive');
expect(0, 'not to be positive');

{unknown} to be a positive integer

✏️ Aliases:

{unknown} to be a positive integer
{unknown} to be a positive int

Success:

expect(42, 'to be a positive integer');
expect(1, 'to be a positive integer');

Failure:

expect(3.14, 'to be a positive integer');
// AssertionError: Expected 3.14 to be a positive integer
expect(-5, 'to be a positive integer');

Negation:

expect(3.14, 'not to be a positive integer');

{unknown} to be negative

✏️ Aliases:

{unknown} to be negative
{unknown} to be a negative number

Success:

expect(-42, 'to be negative');
expect(-3.14, 'to be negative');

Failure:

expect(5, 'to be negative');
// AssertionError: Expected 5 to be negative
expect(0, 'to be negative');

Negation:

expect(5, 'not to be negative');
expect(0, 'not to be negative');

{unknown} to be a negative integer

✏️ Aliases:

{unknown} to be a negative integer
{unknown} to be a negative int

Success:

expect(-42, 'to be a negative integer');
expect(-1, 'to be a negative integer');

Failure:

expect(-3.14, 'to be a negative integer');
// AssertionError: Expected -3.14 to be a negative integer
expect(5, 'to be a negative integer');

Negation:

expect(-3.14, 'not to be a negative integer');

{unknown} to be NaN

Success:

expect(NaN, 'to be NaN');
expect(Number.NaN, 'to be NaN');

Failure:

expect(42, 'to be NaN');
// AssertionError: Expected 42 to be NaN

Negation:

expect(42, 'not to be NaN');

{unknown} to be an integer

✏️ Aliases:

{unknown} to be an integer
{unknown} to be a safe integer
{unknown} to be an int
{unknown} to be a safe int

Success:

expect(42, 'to be an integer');
expect(-17, 'to be an integer');
expect(0, 'to be an integer');

Failure:

expect(3.14, 'to be an integer');
// AssertionError: Expected 3.14 to be an integer

Negation:

expect(3.14, 'not to be an integer');

{unknown} to be greater than {number}

Success:

expect(10, 'to be greater than', 5);
expect(3.14, 'to be greater than', 3);

Failure:

expect(5, 'to be greater than', 10);
// AssertionError: Expected 5 to be greater than 10

Negation:

expect(5, 'not to be greater than', 10);

{unknown} to be less than {number}

✏️ Aliases:

{unknown} to be less than {number}
{unknown} to be lt {number}

Success:

expect(5, 'to be less than', 10);
expect(3, 'to be less than', 3.14);

Failure:

expect(10, 'to be less than', 5);
// AssertionError: Expected 10 to be less than 5

Negation:

expect(10, 'not to be less than', 5);

{unknown} to be greater than or equal to {number}

✏️ Aliases:

{unknown} to be greater than or equal to {number}
{unknown} to be at least {number}
{unknown} to be gte {number}

Success:

expect(10, 'to be greater than or equal to', 10);
expect(15, 'to be at least', 10);

Failure:

expect(5, 'to be greater than or equal to', 10);
// AssertionError: Expected 5 to be greater than or equal to 10

Negation:

expect(5, 'not to be greater than or equal to', 10);

{unknown} to be less than or equal to {number}

✏️ Aliases:

{unknown} to be less than or equal to {number}
{unknown} to be at most {number}
{unknown} to be lte {number}

Success:

expect(10, 'to be less than or equal to', 10);
expect(5, 'to be at most', 10);

Failure:

expect(15, 'to be less than or equal to', 10);
// AssertionError: Expected 15 to be less than or equal to 10

Negation:

expect(15, 'not to be less than or equal to', 10);

{number} to be within {number} and {number}

✏️ Aliases:

{number} to be within {number} and {number}
{number} to be between {number} and {number}

ℹ️ This assertion is inclusive of the boundary values.

Success:

expect(5, 'to be within', 1, 10);
expect(7.5, 'to be between', 7, 8);

Failure:

expect(15, 'to be within', 1, 10);
// AssertionError: Expected 15 to be within 1 and 10

Negation:

expect(15, 'not to be within', 1, 10);

{number} to be close to {number} within {number}

ℹ️ The first number is the subject, the second number is the target, and the third number is the tolerance.

Success:

expect(1.0, 'to be close to', 1.1, 0.2);
expect(3.14159, 'to be close to', 3.14, 0.01);

Failure:

expect(1.0, 'to be close to', 2.0, 0.5);
// AssertionError: Expected 1.0 to be close to 2.0 within 0.5

Negation:

expect(1.0, 'not to be close to', 2.0, 0.5);