Assert

Node.js wrapper aroudn the assert core module.

- Assert
- Goals
- Install
- Methods
- Equality
- Assert.deepStrictEqual()
- Assert.deepNarrowStrictEqual()
- Assert.strictEqual()
- Similarity
- Assert.startsWith()
- Assert.endsWith()
- Assert.includes()
- Math
- Assert.isLessThan()
- Assert.isAtMost()
- Assert.isAtLeast()
- Assert.isGreaterThan()
- Assert.isBetween()
- Emptiness
- Assert.isEmpty()
- Assert.isNotEmpty()
- Kind
- Assert.deepKind()
- Assert.deepNarrowKind()
- Assert.isArray()
- Assert.isBoolean()
- Assert.isBuffer()
- Assert.isDate()
- Assert.isError()
- Assert.isFunction()
- Assert.isMap()
- Assert.isNull()
- Assert.isNumber()
- Assert.isObject()
- Assert.isPromise()
- Assert.isRegexp()
- Assert.isSet()
- Assert.isString()
- Assert.isSymbol()
- Assert.isUint8Array()
- Assert.isUndefined()
- Misc
- Assert.fail()
- Assert.ok()
- Assert.throws()

Goals

- Extend functionality of the assert core module
- Provide more helpful error messages

Install

``bash
npm install @ravdocs/assert
`

Methods

Equality

$3

- label (required) Name of the variable used as the actual parameter. The error message will refer to the actual parameter by this label.
- actual (required) Actual value to test.
- expected (required) Expected value of the actual parameter.

Test for deep equality between the actual and expected parameters. It behaves similar to assert.deepStrictEqual but with these differences:

- Set items are compared ordered.
- Circular references are unsupported; they will result in a stack overflow.

`js
var Assert = require('@ravdocs/assert');

var actual1 = {a: 1};
var expected1 = {a: 1};
Assert.deepStrictEqual('actual1', actual1, expected1);
// OK

var actual2 = {a: 1};
var expected2 = {a: '1'};
Assert.deepStrictEqual('actual2', actual2, expected2);
// AssertionError: Expected kind of 'actual2[a]' to be 'string' but got 'number'.
`

$3

- label (required) Name of the variable used as the actual parameter. The error message will refer to the actual parameter by this label.
- actual (required) Actual value to test.
- expected (required) Expected value of the actual parameter.

Similar to Assert.deepStrictEqual() except that it will pass when the expected parameter is a subset of the actual parameter. Any objects in the expected parameter must exist in the actual parameter, and the keys of these expected objects must exist in the corresponding actual objects, but the actual objects can have more keys than those in the expected ones. This rule applies for objects, arrays, Maps, and Sets. The built-in assert module does not have a counterpart to this method.

`js
var Assert = require('@ravdocs/assert');

var actual1 = {a: 1, b: 1};
var expected1 = {a: 1};
Assert.deepNarrowStrictEqual('actual1', actual1, expected1);
// OK

var actual2 = {a: 1};
var expected2 = {a: 1, b: 1};
Assert.deepNarrowStrictEqual('actual2', actual2, expected2);
// AssertionError: Expected kind of 'actual2[b]' to be 'number' but got 'undefined'.

var actual3 = ['a', 'b'];
var expected3 = ['a'];
Assert.deepNarrowStrictEqual('actual3', actual3, expected3);
// OK

var actual4 = ['a'];
var expected4 = ['a', 'b'];
Assert.deepNarrowStrictEqual('actual4', actual4, expected4);
// AssertionError: Expected kind of 'actual4[1]' to be 'string' but got 'undefined'.
`

$3

- label (required) Name of the variable used as the actual parameter. The error message will refer to the actual parameter by this label.
- actual (required) Actual value to test.
- expected (required) Expected value of the actual parameter.

Test strict equality between the actual and expected parameters. It behaves similar to assert.strictEqual.

`js
var Assert = require('@ravdocs/assert');

var actual1 = 1;
var expected1 = 1;
Assert.strictEqual('actual1', actual1, expected1);
// OK

var actual2 = 1;
var expected2 = '1';
Assert.strictEqual('actual2', actual2, expected2);
// AssertionError: Expected kind of 'actual2' to be 'string' but got 'number'.

var actual3 = 1;
var expected3 = 2;
Assert.strictEqual('actual3', actual3, expected3);
// AssertionError: Expected 'actual3' to be '2' but got '1'.
`

Similarity

$3

- label (required) Name of the variable used as the actual parameter. The error message will refer to the actual parameter by this label.
- actual (required) Actual value to test.
- prefix (required) Expected prefix of the actual parameter.

Test whether actual starts with prefix.

`js
var Assert = require('@ravdocs/assert');

var actual1 = 'ab';
var prefix1 = 'a';
Assert.startsWith('actual1', actual1, prefix1);
// OK

var actual2 = 'ab';
var prefix2 = 'b';
Assert.startsWith('actual2', actual2, prefix2);
// AssertionError: Expected 'actual2' to start with 'b' but it does not.
`

$3

- label (required) Name of the variable used as the actual parameter. The error message will refer to the actual parameter by this label.
- actual (required) Actual value to test.
- suffix (required) Expected suffix of the actual parameter.

Test whether actual ends with suffix.

`js
var Assert = require('@ravdocs/assert');

var actual1 = 'ab';
var suffix1 = 'b';
Assert.endsWith('actual1', actual1, suffix1);
// OK

var actual2 = 'ab';
var suffix2 = 'a';
Assert.endsWith('actual2', actual2, suffix2);
// AssertionError: Expected 'actual2' to end with 'a' but it does not.
`

$3

- label (required) Name of the variable used as the actual parameter. The error message will refer to the actual parameter by this label.
- actual | (required) Actual value to test.
- needle (required) Value expected to be inside the actual parameter.

Test whether actual includes needle.

`js
var Assert = require('@ravdocs/assert');

var actual1 = 'abc';
var needle1 = 'b';
Assert.includes('actual1', actual1, needle1);
// OK

var actual2 = 'abc';
var needle2 = 'd';
Assert.includes('actual2', actual2, needle2);
// AssertionError: Expected 'actual2' to include 'd' but it does not.

var actual3 = ['a', 'b', 'c'];
var needle3 = 'b';
Assert.includes('actual3', actual3, needle3);
// OK

var actual4 = ['a', 'b', 'c'];
var needle4 = 'd';
Assert.includes('actual4', actual4, needle4);
// AssertionError: Expected 'actual4' to include 'd' but it does not.
`

Math

$3

- label (required) Name of the variable used as the actual parameter. The error message will refer to the actual parameter by this label.
- actual (required) Actual value to test.
- bar (required) The actual parameter should be less than (<) this value.

Test whether actual is less than (<) bar.

`js
var Assert = require('@ravdocs/assert');

var actual1 = 4;
var bar1 = 5;
Assert.isLessThan('actual1', actual1, bar1);
// OK

var actual2 = 5;
var bar2 = 5;
Assert.isLessThan('actual2', actual2, bar2);
// AssertionError: Expected 'actual2' to be less than (<) '5' but got '5'.

var actual3 = 6;
var bar3 = 5;
Assert.isLessThan('actual3', actual3, bar3);
// AssertionError: Expected 'actual3' to be less than (<) '5' but got '6'.
`

$3

- label (required) Name of the variable used as the actual parameter. The error message will refer to the actual parameter by this label.
- actual (required) Actual value to test.
- bar (required) The actual parameter should be at most (<=) this value.

Test whether actual is at most (<=) bar.

`js
var Assert = require('@ravdocs/assert');

var actual1 = 4;
var bar1 = 5;
Assert.isAtMost('actual1', actual1, bar1);
// OK

var actual2 = 5;
var bar2 = 5;
Assert.isAtMost('actual2', actual2, bar2);
// OK

var actual3 = 6;
var bar3 = 5;
Assert.isAtMost('actual3', actual3, bar3);
// AssertionError: Expected 'actual3' to be at most (<=) '5' but got '6'.
`

$3

- label (required) Name of the variable used as the actual parameter. The error message will refer to the actual parameter by this label.
- actual (required) Actual value to test.
- bar (required) The actual parameter should be at least (>=) this value.

Test whether actual is at least (>=) bar.

`js
var Assert = require('@ravdocs/assert');

var actual1 = 4;
var bar1 = 5;
Assert.isAtLeast('actual1', actual1, bar1);
// AssertionError: Expected 'actual1' to be at least (>=) '5' but got '4'.

var actual2 = 5;
var bar2 = 5;
Assert.isAtLeast('actual2', actual2, bar2);
// OK

var actual3 = 6;
var bar3 = 5;
Assert.isAtLeast('actual3', actual3, bar3);
// OK
`

$3

- label (required) Name of the variable used as the actual parameter. The error message will refer to the actual parameter by this label.
- actual (required) Actual value to test.
- bar (required) The actual parameter should be greater than (>) this value.

Test whether actual is greater than (>) bar.

`js
var Assert = require('@ravdocs/assert');

var actual1 = 4;
var bar1 = 5;
Assert.isGreaterThan('actual1', actual1, bar1);
// AssertionError: Expected 'actual1' to be greater than (>) '5' but got '4'.

var actual2 = 5;
var bar2 = 5;
Assert.isGreaterThan('actual2', actual2, bar2);
// AssertionError: Expected 'actual2' to be greater than (>) '5' but got '5'.

var actual3 = 6;
var bar3 = 5;
Assert.isGreaterThan('actual3', actual3, bar3);
// OK
`

$3

- label (required) Name of the variable used as the actual parameter. The error message will refer to the actual parameter by this label.
- actual (required) Actual value to test.
- min (required) The actual parameter should be greater than or equal to (>=) this value.
- max (required) The actual parameter should be less than or equal to (<=) this value.

Test whether actual is between min and max. Like the SQL BETWEEN operator, this method is inclusive; the test will pass if actual equals min or max.

`js
var Assert = require('@ravdocs/assert');

var actual1 = 6;
var min1 = 2;
var max1 = 5;
Assert.isBetween('actual1', actual1, min1, max1);
// AssertionError: Expected 'actual1' to be between '2' and '5' but got '6'.

var actual2 = 4;
var min2 = 2;
var max2 = 5;
Assert.isBetween('actual2', actual2, min2, max2);
// OK

var actual3 = 5;
var min3 = 2;
var max3 = 5;
Assert.isBetween('actual3', actual3, min3, max3);
// OK
`

Emptiness

$3

- label (required) Name of the variable used as the actual parameter. The error message will refer to the actual parameter by this label.
- value (required) Actual value to test.

Test whether actual is empty. It uses lodash.isEmpty.

`js
var Assert = require('@ravdocs/assert');

var actual1 = '';
Assert.isEmpty('actual1', actual1);
// OK

var actual2 = [];
Assert.isEmpty('actual2', actual2);
// OK

var actual3 = [''];
Assert.isEmpty('actual3', actual3);
// AssertionError: Expected 'actual3' to be empty but it is not.
`

$3

- label (required) Name of the variable used as the actual parameter. The error message will refer to the actual parameter by this label.
- value (required) Actual value to test.

Test whether actual is not empty. It uses lodash.isEmpty.

`js
var Assert = require('@ravdocs/assert');

var actual1 = '';
Assert.isNotEmpty('actual1', actual1);
// AssertionError: Expected 'actual1' not to be empty but it is.
// OK

var actual2 = [];
Assert.isNotEmpty('actual2', actual2);
// AssertionError: Expected 'actual2' not to be empty but it is.

var actual3 = [''];
Assert.isNotEmpty('actual3', actual3);
// OK
`

Kind

$3

- label (required) Name of the variable used as the actual parameter. The error message will refer to the actual parameter by this label.
- actual (required) Actual value to test.
- expected (required) Expected kind of the actual parameter.

Test whether the kind of actual is expected. Optionally, if expected is an array, object, or Map, it tests for deep kind equality between the actual and expected parameters. It is similar to Assert.deepStrictEqual() except that expected denotes the kinds of values rather than the values themselves. The built-in assert module does not have a counterpart to this method.

`js
var Assert = require('@ravdocs/assert');

var actual1 = {a: 1, b: 'astring'};
var expected1 = {a: 'number', b: 'string'};
Assert.deepKind('actual1', actual1, expected1);
// OK

var actual2 = {a: 1, b: 'astring'};
var expected2 = {a: 'number', b: 'number'};
Assert.deepKind('actual2', actual2, expected2);
// AssertionError: Expected kind of 'actual2[b]' to be 'number' but got 'string'.

var actual3 = [
{a: 1},
{b: 'astring'}
];
var expected3 = [
{a: 'number'},
{b: 'string'}
];
Assert.deepKind('actual3', actual3, expected3);
// OK

var actual4 = [
{a: 1},
{b: 'astring'}
];
var expected4 = [
{a: 'number'},
{b: 'number'}
];
Assert.deepKind('actual4', actual4, expected4);
// AssertionError: Expected kind of 'actual4[b]' to be 'number' but got 'string'.
`

$3

- label (required) Name of the variable used as the actual parameter. The error message will refer to the actual parameter by this label.
- actual (required) Actual value to test.
- expected (required) Expected kind of the actual parameter.

Similar to Assert.deepKind() except that it will pass when the expected parameter is a subset of the actual parameter. Any objects in the expected parameter must exist in the actual parameter, and the keys of these expected objects must exist in the corresponding actual objects, but the actual objects can have more keys than those in the expected ones. This rule applies for objects, arrays, and Maps. The built-in assert module does not have a counterpart to this method.

`js
var Assert = require('@ravdocs/assert');

var actual1 = {a: 1, b: 'astring'};
var expected1 = {a: 'number', b: 'string'};
Assert.deepNarrowKind('actual1', actual1, expected1);
// OK

var actual2 = {a: 1, b: 'astring'};
var expected2 = {a: 'number', b: 'number'};
Assert.deepNarrowKind('actual2', actual2, expected2);
// AssertionError: Expected kind of 'actual2[b]' to be 'number' but got 'string'.

var actual3 = {a: 1, b: 'astring'};
var expected3 = {a: 'number'};
Assert.deepNarrowKind('actual3', actual3, expected3);
// OK

var actual4 = {a: 1};
var expected4 = {a: 'number', b: 'string'};
Assert.deepNarrowKind('actual4', actual4, expected4);
// AssertionError: Expected kind of 'actual4[b]' to be 'number' but got 'undefined'.

var actual5 = {a: 1, b: 'astring'};
var expected5 = 'object';
Assert.deepNarrowKind('actual5', actual5, expected5);
// OK
`

$3

- label (required) Name of the variable used as the actual parameter. The error message will refer to the actual parameter by this label.
- value (required) Actual value to test.

Test whether the kind of actual is 'array'. The kind is calculated with kind-of.

`js
var Assert = require('@ravdocs/assert');

var actual1 = [];
Assert.isArray('actual1', actual1);
// OK

var actual2 = '';
Assert.isArray('actual2', actual2);
// AssertionError: Expected kind of 'actual2' to be 'array' but got 'string'.
`

$3

- label (required) Name of the variable used as the actual parameter. The error message will refer to the actual parameter by this label.
- value (required) Actual value to test.

Test whether the kind of actual is 'boolean'. The kind is calculated with kind-of.

`js
var Assert = require('@ravdocs/assert');

var actual1 = false;
Assert.isBoolean('actual1', actual1);
// OK

var actual2 = '';
Assert.isBoolean('actual2', actual2);
// AssertionError: Expected kind of 'actual2' to be 'boolean' but got 'string'.
`

$3

- label (required) Name of the variable used as the actual parameter. The error message will refer to the actual parameter by this label.
- value (required) Actual value to test.

Test whether the kind of actual is 'buffer'. The kind is calculated with kind-of.

`js
var Assert = require('@ravdocs/assert');

var actual1 = Buffer.from('');
Assert.isBuffer('actual1', actual1);
// OK

var actual2 = '';
Assert.isBuffer('actual2', actual2);
// AssertionError: Expected kind of 'actual2' to be 'buffer' but got 'string'.
`

$3

- label (required) Name of the variable used as the actual parameter. The error message will refer to the actual parameter by this label.
- value (required) Actual value to test.

Test whether the kind of actual is 'date'. The kind is calculated with kind-of.

`js
var Assert = require('@ravdocs/assert');

var actual1 = new Date();
Assert.isDate('actual1', actual1);
// OK

var actual2 = '';
Assert.isDate('actual2', actual2);
// AssertionError: Expected kind of 'actual2' to be 'date' but got 'string'.
`

$3

- label (required) Name of the variable used as the actual parameter. The error message will refer to the actual parameter by this label.
- value (required) Actual value to test.

Test whether the kind of actual is 'error'. The kind is calculated with kind-of.

`js
var Assert = require('@ravdocs/assert');

var actual1 = new Error('Test');
Assert.isError('actual1', actual1);
// OK

var actual2 = '';
Assert.isError('actual2', actual2);
// AssertionError: Expected kind of 'actual2' to be 'error' but got 'string'.
`

$3

- label (required) Name of the variable used as the actual parameter. The error message will refer to the actual parameter by this label.
- value (required) Actual value to test.

Test whether the kind of actual is 'function'. The kind is calculated with kind-of.

`js
var Assert = require('@ravdocs/assert');

var actual1 = function() {};
Assert.isFunction('actual1', actual1);
// OK

var actual2 = '';
Assert.isFunction('actual2', actual2);
// AssertionError: Expected kind of 'actual2' to be 'function' but got 'string'.
`

$3

- label (required) Name of the variable used as the actual parameter. The error message will refer to the actual parameter by this label.
- value (required) Actual value to test.

Test whether the kind of actual is 'map'. The kind is calculated with kind-of.

`js
var Assert = require('@ravdocs/assert');

var actual1 = new Map();
Assert.isMap('actual1', actual1);
// OK

var actual2 = '';
Assert.isMap('actual2', actual2);
// AssertionError: Expected kind of 'actual2' to be 'map' but got 'string'.
`

$3

- label (required) Name of the variable used as the actual parameter. The error message will refer to the actual parameter by this label.
- value (required) Actual value to test.

Test whether the kind of actual is 'null'. The kind is calculated with kind-of.

`js
var Assert = require('@ravdocs/assert');

var actual1 = null;
Assert.isNull('actual1', actual1);
// OK

var actual2 = '';
Assert.isNull('actual2', actual2);
// AssertionError: Expected kind of 'actual2' to be 'null' but got 'string'.
`

$3

- label (required) Name of the variable used as the actual parameter. The error message will refer to the actual parameter by this label.
- value (required) Actual value to test.

Test whether the kind of actual is 'number'. The kind is calculated with kind-of.

`js
var Assert = require('@ravdocs/assert');

var actual1 = 1;
Assert.isNumber('actual1', actual1);
// OK

var actual2 = '';
Assert.isNumber('actual2', actual2);
// AssertionError: Expected kind of 'actual2' to be 'number' but got 'string'.
`

$3

- label (required) Name of the variable used as the actual parameter. The error message will refer to the actual parameter by this label.
- value (required) Actual value to test.

Test whether the kind of actual is 'object'. The kind is calculated with kind-of.

`js
var Assert = require('@ravdocs/assert');

var actual1 = {};
Assert.isObject('actual1', actual1);
// OK

var actual2 = '';
Assert.isObject('actual2', actual2);
// AssertionError: Expected kind of 'actual2' to be 'object' but got 'string'.
`

$3

- label (required) Name of the variable used as the actual parameter. The error message will refer to the actual parameter by this label.
- value (required) Actual value to test.

Test whether the kind of actual is 'promise'. The kind is calculated with kind-of.

`js
var Assert = require('@ravdocs/assert');

var actual1 = new Promise(function(resolve) {
resolve();
});
Assert.isPromise('actual1', actual1);
// OK

var actual2 = '';
Assert.isPromise('actual2', actual2);
// AssertionError: Expected kind of 'actual2' to be 'promise' but got 'string'.
`

$3

- label (required) Name of the variable used as the actual parameter. The error message will refer to the actual parameter by this label.
- value (required) Actual value to test.

Test whether the kind of actual is 'regexp'. The kind is calculated with kind-of.

`js
var Assert = require('@ravdocs/assert');

var actual1 = /\d+/;
Assert.isRegexp('actual1', actual1);
// OK

var actual2 = '';
Assert.isRegexp('actual2', actual2);
// AssertionError: Expected kind of 'actual2' to be 'regexp' but got 'string'.
`

$3

- label (required) Name of the variable used as the actual parameter. The error message will refer to the actual parameter by this label.
- value (required) Actual value to test.

Test whether the kind of actual is 'set'. The kind is calculated with kind-of.

`js
var Assert = require('@ravdocs/assert');

var actual1 = new Set();
Assert.isSet('actual1', actual1);
// OK

var actual2 = '';
Assert.isSet('actual2', actual2);
// AssertionError: Expected kind of 'actual2' to be 'set' but got 'string'.
`

$3

- label (required) Name of the variable used as the actual parameter. The error message will refer to the actual parameter by this label.
- value (required) Actual value to test.

Test whether the kind of actual is 'string'. The kind is calculated with kind-of.

`js
var Assert = require('@ravdocs/assert');

var actual1 = '1';
Assert.isString('actual1', actual1);
// OK

var actual2 = 1;
Assert.isString('actual2', actual2);
// AssertionError: Expected kind of 'actual2' to be 'string' but got 'number'.
`

$3

- label (required) Name of the variable used as the actual parameter. The error message will refer to the actual parameter by this label.
- value (required) Actual value to test.

Test whether the kind of actual is 'symbol'. The kind is calculated with kind-of.

`js
var Assert = require('@ravdocs/assert');

var actual1 = Symbol('1');
Assert.isSymbol('actual1', actual1);
// OK

var actual2 = '';
Assert.isSymbol('actual2', actual2);
// AssertionError: Expected kind of 'actual2' to be 'symbol' but got 'string'.
`

$3

- label (required) Name of the variable used as the actual parameter. The error message will refer to the actual parameter by this label.
- value (required) Actual value to test.

Test whether the kind of actual is 'uint8array'. The kind is calculated with kind-of.

`js
var Assert = require('@ravdocs/assert');

var actual1 = new Uint8Array();
Assert.isUint8Array('actual1', actual1);
// OK

var actual2 = '';
Assert.isUint8Array('actual2', actual2);
// AssertionError: Expected kind of 'actual2' to be 'uint8array' but got 'string'.
`

$3

- label (required) Name of the variable used as the actual parameter. The error message will refer to the actual parameter by this label.
- value (required) Actual value to test.

Test whether the kind of actual is 'undefined'. The kind is calculated with kind-of.

`js
var Assert = require('@ravdocs/assert');

var actual1;
Assert.isUndefined('actual1', actual1);
// OK

var actual2 = '';
Assert.isUndefined('actual2', actual2);
// AssertionError: Expected kind of 'actual2' to be 'undefined' but got 'string'.
`

Misc

$3

- message

Alias of assert.fail.

`js
var Assert = require('@ravdocs/assert');

Assert.fail();
// AssertionError [ERR_ASSERTION]: Failed

Assert.fail('An error occurred');
// AssertionError [ERR_ASSERTION]: An error occurred
`

$3

- label (required) Name of the variable used as the actual parameter. The error message will refer to the actual parameter by this label.
- actual (required) Actual value to test.

Test whether actual is truthy. It behaves similar to assert.ok.

`js
var Assert = require('@ravdocs/assert');

var actual1 = 1;
Assert.ok('actual1', actual1);
// OK

var actual2 = 0;
Assert.ok('actual2', actual2);
// AssertionError: Expected 'actual2' to be truthy but it is not.
`

$3

- fn (required)
- error | |