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List of Enforce rules

Enforce rules are functions that allow you to test your data against different criteria. The following rules are supported out-of-the-box.

equals

Description

Checks if your enforced value strictly equals (===) another.

It is not recommended to use this rule to compare arrays or objects, as it does not perform any sort of deep comparison on the value.

For numeric value comparison, you should use numberEquals, which coerces numeric strings into numbers before comparing.

Arguments

  • value: Any value you wish to check your enforced value against

Usage examples:

enforce(1).equals(1);

enforce('hello').equals('hello');

const a = [1, 2, 3];

enforce(a).equals(a);
// passes
enforce('1').equals(1);
enforce([1, 2, 3]).equals([1, 2, 3]);
// throws

notEquals

Description

Checks if your enforced value does not strictly equal (===) another.

Reverse implementation of equals.

Usage examples:

enforce('1').notEquals(1);
enforce([1, 2, 3]).notEquals([1, 2, 3]);
// passes
enforce(1).notEquals(1);
enforce('hello').notEquals('hello');

const a = [1, 2, 3];

enforce(a).notEquals(a);
// throws

isEmpty

Description

Checks if your enforced value is empty, false, zero, null or undefined.

Expected results are:

  • object: checks against the count of keys (0 is empty)
  • array/string: checks against length. (0 is empty)
  • number: checks the value of the number. (0 and NaN are empty)
  • boolean: false is empty.
  • undefined/null: are both empty.

Usage examples:

enforce([]).isEmpty();
enforce('').isEmpty();
enforce({}).isEmpty();
enforce(0).isEmpty();
enforce(NaN).isEmpty();
enforce(undefined).isEmpty();
enforce(null).isEmpty();
enforce(false).isEmpty();
// passes
enforce([1]).isEmpty();
enforce('1').isEmpty();
enforce({ 1: 1 }).isEmpty();
enforce(1).isEmpty();
enforce(true).isEmpty();
// throws

isNotEmpty

Description

Checks that your enforced value is not empty, false, or zero. Reverse implementation of isEmpty.

Usage examples:

enforce([1]).isNotEmpty();
enforce('1').isNotEmpty();
enforce({ 1: 1 }).isNotEmpty();
// passes
enforce([]).isNotEmpty();
enforce('').isNotEmpty();
enforce({}).isNotEmpty();
enforce(0).isNotEmpty();
// throws

isNumeric

Description

Checks if a value is a representation of a real number

Usage examples:

enforce(143).isNumeric();
enforce('143').isNumeric();
// passes
enforce(NaN).isNumeric();
enforce('1hello').isNumeric();
enforce('hi').isNumeric();
// throws

isNotNumeric

Description

Checks if a value is not a representation of a real number. Reverse implementation of isNumeric.

Usage examples:

enforce(NaN).isNotNumeric();
enforce('Hello World!').isNotNumeric();
// passes
enforce(731).isNotNumeric();
enforce('42').isNotNumeric();
// throws

greaterThan

  • alias: gt

Description

Checks that your numeric enforced value is larger than a given numeric value.

Arguments

  • value: number | string | A numeric value against which you want to check your enforced value.

Strings are parsed using Number(), values which are not fully numeric always return false;

Usage

enforce(1).greaterThan(0);
enforce('10').greaterThan(0);
enforce(900).gt('100');
// passes
enforce(100).greaterThan(100);
enforce('100').greaterThan(110);
enforce([100]).gt(1);
// throws

greaterThanOrEquals

  • alias: gte()

Description

Checks that your numeric enforced value is larger than or equals a given numeric value.

Arguments

  • value: number | string | A numeric value against which you want to check your enforced value.

Strings are parsed using Number(), values which are not fully numeric always return false;

Usage

enforce(1).greaterThanOrEquals(0);
enforce('10').greaterThanOrEquals(0);
enforce(900).greaterThanOrEquals('100');
enforce(100).greaterThanOrEquals('100');
enforce(900).gte('900');
enforce('1337').gte(1337);
// passes
enforce(100).greaterThanOrEquals('120');
enforce('100').greaterThanOrEquals(110);
enforce([100]).gte(1);
// throws

lengthEquals

Description

Checks that your enforced value is equal to the given number.

Arguments

  • size: number | the number which you would like your initial value to be tested against.

The value argument can be of the following types:

  • array: checks against length.
  • string: checks against length.

Usage examples:

enforce([1]).lengthEquals(1);
enforce('a').lengthEquals(1);
// passes
enforce([1, 2]).lengthEquals(1);
enforce('').lengthEquals(1);
// throws

lengthNotEquals

Description

Checks that your enforced value is not equal to the given number. Reverse implementation of lengthEquals.

Arguments

  • size: number | the number which you would like your initial value to be tested against.

The value argument can be of the following types:

  • array: checks against length.
  • string: checks against length.

Usage examples:

enforce([1]).lengthNotEquals(0);
enforce('a').lengthNotEquals(3);
// passes
enforce([1]).lengthNotEquals(1);
enforce('').lengthNotEquals(0);
// throws

lessThan

  • alias: lt()

Description

Checks that your numeric enforced value is smaller than a given numeric value.

Arguments

  • value: number | string | A numeric value against which you want to check your enforced value.

Strings are parsed using Number(), values which are not fully numeric always return false;

Usage

enforce(0).lessThan(1);
enforce(2).lessThan('10');
enforce('90').lt(100);
// passes
enforce(100).lessThan(100);
enforce('110').lessThan(100);
enforce([0]).lt(1);
// throws

lessThanOrEquals

  • alias: lte()

Description

Checks that your numeric enforced value is smaller than or equals a given numeric value.

Arguments

  • value: number | string | A numeric value against which you want to check your enforced value.

Strings are parsed using Number(), values which are not fully numeric always return false;

Usage

enforce(0).lessThanOrEquals(1);
enforce(2).lessThanOrEquals('10');
enforce('90').lte(100);
enforce(100).lte('100');
// passes
enforce(100).lessThanOrEquals(90);
enforce('110').lessThanOrEquals(100);
enforce([0]).lte(1);
// throws

longerThan

Description

Checks that your enforced value is longer than a given number.

Arguments

  • size: number | the number which you would like your initial value to be tested against.

The value argument can be of the following types:

  • array: checks against length.
  • string: checks against length.

Usage examples:

enforce([1]).longerThan(0);
enforce('ab').longerThan(1);
// passes
enforce([1]).longerThan(2);
enforce('').longerThan(0);
// throws

longerThanOrEquals

Description

Checks that your enforced value is longer than or equals a given number.

Arguments

  • size: number | the number which you would like your initial value to be tested against.

The value argument can be of the following types:

  • array: checks against length.
  • string: checks against length.

Usage examples:

enforce([1]).longerThanOrEquals(0);
enforce('ab').longerThanOrEquals(1);
enforce([1]).longerThanOrEquals(1);
enforce('a').longerThanOrEquals(1);
// passes
enforce([1]).longerThanOrEquals(2);
enforce('').longerThanOrEquals(1);
// throws

numberEquals

Description

Checks that your numeric enforced value is equals another value.

Arguments

  • value: number | string | A numeric value against which you want to check your enforced value.

Strings are parsed using Number(), values which are not fully numeric always return false;

Usage

enforce(0).numberEquals(0);
enforce(2).numberEquals('2');
// passes
enforce(100).numberEquals(10);
enforce('110').numberEquals(100);
enforce([0]).numberEquals(1);
// throws

numberNotEquals

Description

Checks that your numeric enforced value does not equal another value. Reverse implementation of numberEquals.

Arguments

  • value: number | string | A numeric value against which you want to check your enforced value.

Strings are parsed using Number(), values which are not fully numeric always return false;

Usage

enforce(2).numberNotEquals(0);
enforce('11').numberNotEquals('10');
// passes
enforce(100).numberNotEquals(100);
enforce('110').numberNotEquals(100);
// throws

shorterThan

Description

Checks that your enforced value is shorter than a given number.

Arguments

  • size: number | the number which you would like your initial value to be tested against.

The value argument can be of the following types:

  • array: checks against length.
  • string: checks against length.

Usage examples:

enforce([]).shorterThan(1);
enforce('a').shorterThan(2);
// passes
enforce([1]).shorterThan(0);
enforce('').shorterThan(0);
// throws

shorterThanOrEquals

Description

Checks that your enforced value is shorter than or equals a given number.

Arguments

  • size: number | the number which you would like your initial value to be tested against.

The value argument can be of the following types:

  • array: checks against length.
  • string: checks against length.

Usage examples:

enforce([]).shorterThanOrEquals(1);
enforce('a').shorterThanOrEquals(2);
enforce([]).shorterThanOrEquals(0);
enforce('a').shorterThanOrEquals(1);
// passes
enforce([1]).shorterThanOrEquals(0);
enforce('ab').shorterThanOrEquals(1);
// throws

matches

Description

Checks if a value contains a regex match.

Arguments

  • regexp: either a RegExp object, or a RegExp valid string

Usage examples:

enforce(1984).matches(/[0-9]/);
enforce(1984).matches('[0-9]');
enforce('1984').matches(/[0-9]/);
enforce('1984').matches('[0-9]');
enforce('198four').matches(/[0-9]/);
enforce('198four').matches('[0-9]');
// passes
enforce('ninety eighty four').matches(/[0-9]/);
enforce('ninety eighty four').matches('[0-9]');
// throws

notMatches

Description

Checks if a value does not contain a regex match. Reverse implementation of matches.

Usage examples:

enforce(1984).notMatches(/[0-9]/);
// throws
enforce('ninety eighty four').notMatches('[0-9]');
// passes

inside

Description

Checks if your enforced value is contained in another array or string. Your enforced value can be of the following types:

  • string
  • number
  • boolean

Arguments

  • container: a string or an array which may contain the value specified.

Usage examples:

inside: array

Checks for membership in an array.

  • string: checks if a string is an element in an array
enforce('hello').inside(['hello', 'world']);
// passes
enforce('hello!').inside(['hello', 'world']);
// throws
  • number: checks if a number is an element in an array
enforce(1).inside([1, 2]);
// passes
enforce(3).inside([1, 2]);
// throws
  • boolean: checks if a number is an element in an array
enforce(false).inside([true, false]);
// passes
enforce(true).inside([1, 2, 3]);
// throws

inside: string

  • string: checks if a string is inside another string
enforce('da').inside('tru dat.');
// passes
enforce('ad').inside('tru dat.');
// throws

notInside

Description

Checks if a given value is not contained in another array or string. Reverse implementation of inside.

Usage examples:

enforce('ad').notInside('tru dat.');
enforce('hello!').notInside(['hello', 'world']);
// passes
enforce('hello').notInside(['hello', 'world']);
enforce('da').notInside('tru dat.');
// throws

isTruthy

Description

Checks if a value is truthy; Meaning: if it can be coerced into boolean true. Anything not in the following list is considered to be truthy.

  • undefined
  • null
  • false
  • 0
  • NaN
  • empty string ("")

Usage examples:

enforce('hello').isTruthy();
enforce(true).isTruthy();
enforce(1).isTruthy();
// passes
enforce(false).isTruthy();
enforce(null).isTruthy();
enforce(undefined).isTruthy();
enforce(0).isTruthy();
enforce(NaN).isTruthy();
enforce('').isTruthy();
// throws

isFalsy

Description

Checks if a value is falsy; Meaning: if it can be coerced into boolean false. Reverse implementation of isTruthy.

Anything not in the following list is considered to be truthy:

  • undefined
  • null
  • false
  • 0
  • NaN
  • empty string ("")

Usage examples:

enforce(false).isFalsy();
enforce(0).isFalsy();
enforce(undefined).isFalsy();
// passes
enforce(1).isFalsy();
enforce(true).isFalsy();
enforce('hi').isFalsy();
// throws

isArray

Description

Checks if a value is of type Array.

Usage examples:

enforce(['hello']).isArray();
// passes
enforce('hello').isArray();
// throws

isNotArray

Description

Checks if a value is of any type other than Array. Reverse implementation of isArray.

Usage examples:

enforce(['hello']).isNotArray();
// throws
enforce('hello').isNotArray();
// passes

isBoolean

Description

Checks if a value is of type boolean. Equals typeof value === 'boolean'

Usage examples:

enforce(true).isBoolean();
enforce(false).isBoolean();
enforce(!!0).isBoolean();
// passes
enforce([]).isBoolean();
enforce('143').isBoolean();
enforce('false').isBoolean();
// throws

isNotBoolean

Description

Checks if a value is of any type other than boolean. Reverse implementation of isBoolean.

Usage examples:

enforce('143').isNotBoolean();
enforce(143).isNotBoolean();
// passes
enforce(true).isNotBoolean();
enforce(false).isNotBoolean();
// throws

isBlank

Description

Determines whether an enforced string contains only whitespaces. It will also check for null or undefined. All other values will return false - to not be confused with isEmpty.

Usage examples:

enforce('   ').isBlank(); // passes
enforce('not blank').isBlank(); // throws

isNotBlank

Description

Determines whether an enforced string contains at least a non-whitespace character. Will also return true for null or undefined. Any other value will return true. This is the reverse of isBlank.

Usage examples:

enforce('not blank').isNotBlank(); // passes
enforce(' ').isNotBlank(); // throws

isNumber

Description

Checks if a value is of type number. Equals typeof value === 'number'

Usage examples:

enforce(143).isNumber();
enforce(NaN).isNumber(); // (NaN is of type 'number!')
// passes
enforce([]).isNumber();
enforce('143').isNumber();
// throws

isNotNumber

Description

Checks if a value is of any type other than number. Reverse implementation of isNumber.

note isNotNumber does not check for NaN value. For NaN values, use isNaN.

Usage examples:

enforce('143').isNotNumber();
enforce(143).isNotNumber();
// passes
enforce(143).isNotNumber();
enforce(NaN).isNotNumber(); // throws (NaN is of type 'number!')
// throws

isNaN

Description

A wrapper around JavaScripts Number.isNaN() function. Checks if a value is NaN.

Usage examples:

enforce(NaN).isNaN();
enforce('A' / 'B').isNaN();
// passes
enforce(null * null).isNaN(); // null*null = 0
enforce(200).isNaN();
enforce('1984').isNaN();
// throws

isNotNaN

Description

Reverse implementation of isNaN. Checks that a value is not NaN.

Usage examples:

enforce(null * null).isNaN(); // null*null = 0
enforce(200).isNaN();
enforce('1984').isNaN();
// passes
enforce(NaN).isNaN();
enforce('A' / 'B').isNaN();
// throws

isNull

Description

Enforces that a specified value is null.

Usage examples:

enforce(null).isNull();
// passes
enforce(undefined).isNull();
enforce(true).isNull();
// throws

isNotNull

Description

Reverse implementation of isNull. Checks that a value is not null.

Usage examples:

enforce('hello').isNull();
enforce(200).isNull();
// passes
enforce(null).isNull();
// throws

isNullish

Description

Checks if a value is either null or undefined.

Usage examples:

enforce(null).isNullish(); // passes
enforce(undefined).isNullish(); // passes
enforce('hello').isNullish(); // throws
enforce(200).isNullish(); // throws

isNotNullish

Description

Checks if a value is not null or undefined.

Usage examples:

enforce('hello').isNotNullish(); // passes
enforce(200).isNotNullish(); // passes
enforce(null).isNotNullish(); // throws
enforce(undefined).isNotNullish(); // throws

isString

Description

Checks if a value is of type String.

Usage examples:

enforce('hello').isString();
// passes
enforce(['hello']).isString();
enforce(1984).isString();
// throws

isNotString

Description

Checks if a value is of any type other than String. Reverse implementation of isString.

Usage examples:

enforce('hello').isNotString();
// throws
enforce(['hello']).isNotString();
// passes

isUndefined

Description

Enforces that a given value is (===) undefined.

Usage examples:

enforce().isUndefined();
enforce(undefined).isUndefined();
// passes
enforce(null).isUndefined();
enforce(true).isUndefined();
// throws

isOdd

Description

Checks if a value is an odd numeric value.

Usage examples:

enforce('1').isOdd();
enforce(9).isOdd();
// passes
enforce(2).isOdd();
enforce('4').isOdd();
enforce('1withNumber').isOdd();
enforce([1]).isOdd();
// throws

isEven

Description

Checks if a value is an even numeric value.

Usage examples:

enforce(0).isEven();
enforce('2').isEven();
// passes
enforce(1).isEven();
enforce('3').isEven();
enforce('2withNumber').isEven();
enforce([0]).isEven();
// throws

isBetween

Description

Checks if a number is in the range of two numbers (edges of range included)

Usage examples:

enforce(5).isBetween(0, 5);
enforce(5).isBetween(0, 10);
enforce(-5).isBetween(-10, -1);
enforce(-5.5).isBetween(-10, -1);
enforce(-5.5).isBetween(-10, -1.1);
enforce(-5.5).isBetween(-9.5, -1.1);
// passes
enforce(5).isBetween(0, 2);
enforce(-5).isBetween(0, 2);
enforce('some_string').isBetween(0, 2);
enforce(false).isBetween(0, 2);
// throws

isNotBetween

Description

Checks if a number is not in range of two numbers (edges of range excluded)

Usage examples:

enforce(5).isNotBetween(0, 4);
enforce(5).isNotBetween(0, 10);
enforce(-5).isNotBetween(-10, -1);
enforce(-5.5).isNotBetween(-10, -1);
enforce(-5.5).isNotBetween(-10, -1.1);
// passes
enforce(5).isNotBetween(0, 5);
enforce(5).isNotBetween(0, 10);
enforce(-5).isNotBetween(-10, -1);
enforce(-5).isNotBetween(-5, -1);
enforce('some_string').isNotBetween(0, 2);
enforce(false).isNotBetween(0, 2);
// throws

endsWith

Description

Determines whether a string ends with the characters of a specified string.

Usage examples:

enforce('aba').endsWith('ba');
enforce('some_string').endsWith('_string');
enforce('string with spaces').endsWith('ng with spaces');
enforce('aaaa ').endsWith(' ');
// passes
enforce('for').endsWith('tor');
enforce('aaaab').endsWith('aaaa');
enforce('aa').endsWith('aaa');
enforce(42).endsWith('b');
enforce(42).endsWith(50);
enforce(true).endsWith(100);
// throws

doesNotEndWith

Description

Determines whether a string does not end with the characters of a specified string. Reverse implementation of endsWith.

startsWith

Description

Determines whether a string starts with the characters of a specified string.

Usage examples:

enforce('aba').startsWith('ab');
enforce('some_string').startsWith('some_');
enforce('string with spaces').startsWith('string with s');
enforce('aaaa ').startsWith('aaaa ');
// passes
enforce('for').startsWith('tor');
enforce('aaaab').startsWith('aab');
enforce('aa').startsWith('aaa');
enforce(42).startsWith('b');
enforce(42).startsWith(50);
enforce(true).startsWith(100);
// throws

doesNotStartWith

Description

Determines whether a string does not start with the characters of a specified string. Reverse implementation of startsWith.

Usage examples:

enforce('for').doesNotStartWith('tor');
enforce('aaaab').doesNotStartWith('aab');
enforce('aa').doesNotStartWith('aaa');
enforce(42).doesNotStartWith('b');
enforce(42).doesNotStartWith(50);
enforce(true).doesNotStartWith(100);
// passes
enforce('aba').doesNotStartWith('ab');
enforce('some_string').doesNotStartWith('some_');
enforce('string with spaces').doesNotStartWith('string with s');
enforce('aaaa ').doesNotStartWith('aaaa ');
// throws

isNegative

Description

Determines whether a numeric value is negative or not.

Usage examples:

enforce(-10).isNegative(); //passes
enforce(-10.12).isNegative(); //passes
enforce('-10.12').isNegative(); //passes
enforce(10).isNegative(); // throws
enforce('10').isNegative(); // throws

isPositive

Description

Determines whether a numeric value is positive or not.

Usage examples:

enforce(10).isPositive(); //passes
enforce(10.12).isPositive(); //passes
enforce('10.12').isPositive(); //passes
enforce(-10).isPositive(); // throws
enforce('-10.12').isPositive(); // throws

isValueOf

Description

Determines whether a value exists as inside an object.

Usage examples:

enforce('Bravo').isValueOf({ a: 'Alpha', b: 'Bravo', c: 'Charlie' });
// passes
enforce('Delta').isValueOf({ a: 'Alpha', b: 'Bravo', c: 'Charlie' });
// throws

isNotValueOf

Description

Determines whether a string is not a value of an object..

Usage examples:

enforce('Delta').isNotValueOf({ a: 'Alpha', b: 'Bravo', c: 'Charlie' });
// passes
enforce('Bravo').isNotValueOf({ a: 'Alpha', b: 'Bravo', c: 'Charlie' });
// throws

isKeyOf

Description

Determines whether a value is a key of an object

Usage examples:

enforce('bananas').isKeyOf({ bananas: 5 });
enforce(1976).isKeyOf({ 1976: 'Rocky' });

// passes
enforce('avocados').isKeyOf({ cantelopes: 5 });
enforce(1967).isKeyOf({ 1988: 'Rain Man' });
enforce('key').isKeyOf(undefined);
enforce(15).isKeyOf(null);
enforce('star').isKeyOf(false);
enforce('triangle').isKeyOf(true);
// throws

isNotKeyOf

Description

Determines whether a value is not a key of an object

Usage examples:

enforce('avocados').isNotKeyOf({ cantelopes: 5 });
enforce(1967).isNotKeyOf({ 1988: 'Rain Man' });
enforce('key').isNotKeyOf(undefined);
enforce(15).isNotKeyOf(null);
enforce('star').isNotKeyOf(false);
enforce('triangle').isNotKeyOf(true);
// passes
enforce('bananas').isNotKeyOf({ bananas: 5 });
enforce(1976).isNotKeyOf({ 1976: 'Rocky' });
// throws