expect-more

expect-more

Curried JavaScript Type Testing Library with Zero Dependencies

Installation

npm install expect-more --save-dev

Usage

import { endsWith, isWithinRange } from 'expect-more';

const result: boolean = endsWith('Script', 'JavaScript');
// => true

const endsWithScript = endsWith('Script');
endsWithScript('JavaScript');
// => true

isWithinRange(10, 20, 21);
// => false

[0, 1, 1, 2, 3, 5, 8, 13, 21, 34].filter(isWithinRange(5, 15));
// => [5, 8, 13]

API: expect-more

General

export declare const isBoolean: (value: unknown) => value is boolean;
export declare const isFalse: (value: unknown) => value is false;
export declare const isNull: (value: unknown) => value is null;
export declare const isRegExp: (value: unknown) => value is RegExp;
export declare const isTrue: (value: unknown) => value is true;
export declare const isUndefined: (value: unknown) => value is undefined;

Functions

export declare const isAsyncFunction: <T = (...args: any[]) => Promise<any>>(
  value: unknown,
) => value is T;
export declare const isFunction: <T = (...args: any[]) => any>(value: unknown) => value is T;
export declare const isGeneratorFunction: <T = Generator>(value: unknown) => value is T;
export declare const throwsAnyError: <T = (...args: any[]) => any>(value: unknown) => value is T;
export declare const throwsErrorOfType: <T = (...args: any[]) => any>(
  typeName: string,
  value: unknown,
) => value is T;

Objects

export declare const hasMember: <T = any>(memberName: string, value: unknown) => value is T;
export declare const isEmptyObject: <T = any>(value: unknown) => value is T;
export declare const isNonEmptyObject: <T = any>(value: unknown) => value is T;
export declare const isObject: <T = any>(value: unknown) => value is T;
export declare const isWalkable: <T = any>(value: unknown) => value is T;

Arrays

export declare const isArray: <T extends any[] = any[]>(value: unknown) => value is T;
export declare const isArrayOfBooleans: (value: unknown) => value is boolean[];
export declare const isArrayOfNumbers: (value: unknown) => value is number[];
export declare const isArrayOfObjects: <T extends any[] = any[]>(value: unknown) => value is T;
export declare const isArrayOfSize: <T extends any[] = any[]>(
  size: number,
  value: unknown,
) => value is T;
export declare const isArrayOfStrings: (value: unknown) => value is string[];
export declare const isEmptyArray: <T extends [] = []>(any) => value is T;
export declare const isNonEmptyArray: <T extends any[] = any[]>(value: unknown) => value is T;

Dates

export declare const isAfter: (other: Date, value: unknown) => value is Date;
export declare const isBefore: (other: Date, value: unknown) => value is Date;
export declare const isDate: (value: unknown) => value is Date;
export declare const isValidDate: (value: unknown) => value is Date;

Numbers

export declare const isCalculable: (value: unknown) => value is number;
export declare const isDecimalNumber: (value: unknown) => value is number;
export declare const isDivisibleBy: (other: number, value: unknown) => value is number;
export declare const isEvenNumber: (value: unknown) => value is number;
export declare const isGreaterThanOrEqualTo: (other: number, value: unknown) => value is number;
export declare const isLessThanOrEqualTo: (other: number, value: unknown) => value is number;
export declare const isNear: (other: number, epsilon: number, value: unknown) => value is number;
export declare const isNumber: (value: unknown) => value is number;
export declare const isOddNumber: (value: unknown) => value is number;
export declare const isWholeNumber: (value: unknown) => value is number;
export declare const isWithinRange: (
  floor: number,
  ceiling: number,
  value: unknown,
) => value is number;

Strings

export declare const endsWith: (other: string, value: unknown) => value is number;
export declare const isEmptyString: (value: unknown) => value is number;
export declare const isIso8601: (value: unknown) => value is number;
export declare const isJsonString: (value: unknown) => value is number;
export declare const isLongerThan: (other: string, value: unknown) => value is number;
export declare const isNonEmptyString: (value: unknown) => value is number;
export declare const isSameLengthAs: (other: string, value: unknown) => value is number;
export declare const isShorterThan: (other: string, value: unknown) => value is number;
export declare const isString: (value: unknown) => value is number;
export declare const isVisibleString: (value: unknown) => value is number;
export declare const isWhitespace: (value: unknown) => value is number;
export declare const startsWith: (other: string, value: unknown) => value is number;

API: expect-more/gen

export declare const withMissingBranches: (value: object | any[]) => Generator;
export declare const withMissingLeaves: (value: object | any[]) => Generator;
export declare const withMissingNodes: (value: object | any[]) => Generator;
export declare const withNullBranches: (value: object | any[]) => Generator;
export declare const withNullLeaves: (value: object | any[]) => Generator;
export declare const withNullNodes: (value: object | any[]) => Generator;