ts-prime/dist/es/guards.js

A utility library for JavaScript and Typescript.

/**
 * Checks if `data` is `Number`
 * @param data - Anything
 * @example
 * const item = { data: 1 } as { data: number } | string
 * if (P.isString(item)) {
 *    console.log("My name is", item)
 * }
 * @category Guard
 */
// @ts-ignore
export function isString(data) {
    return typeof data === 'string';
}
/**
 * Checks if `data` is `Number`
 * @param data - Anything
 * @example
 * const item = { data: 1 } as { data: number } | number
 * if (P.isNumber(item)) {
 *    console.log("My phone number is", item)
 * }
 * @category Guard
 */
// @ts-ignore
export function isNumber(data) {
    return typeof data === 'number' && !isNaN(data);
}
/**
 * Checks if `data` is defined
 * @param data - Anything
 * @example
 * const item = { data: 1 } as { data: number } | undefined
 * if (P.isDefined(item)) {
 *    console.log(item.data)
 * }
 * @category Guard
 */
export function isDefined(data) {
    return typeof data !== 'undefined' && data !== null;
}
/**
 * Checks if `data` is boolean
 * @param data - Anything
 * @example
 * const item = false as { data: number } | undefined | boolean
 * if (P.isBoolean(item)) {
 *    console.log(item.data)
 * }
 * @category Guard
 */
// @ts-ignore
export function isBoolean(data) {
    return typeof data === 'boolean';
}
/**
 * Checks if `data` is `Promise`.
 * @param data - Anything
 * @example
 * const item = { data: 1 } as { data: number } | Promise<string[]>
 * if (P.isPromise(item)) {
 *    const result = await item
 *    console.log(Promise resolved,result.map((q)=> q.match(/.../)))
 * }
 * // Item is not promise
 * @category Guard
 */
// @ts-ignore
export function isPromise(data) {
    return data instanceof Promise;
}
/**
 * Checks if `data` is `array`.
 * @param data - Anything
 * @example
 * const item = { data: 1 } as { data: number } | string[]
 * if (P.isArray(item)) {
 *    console.log(item.map((q)=> q.match(/.../)))
 * }
 *
 * const items = [{ data: 1 },[],"1",4,P.clamp].filter(P.isArray) //=> ["1"]
 * @category Guard
 */
export function isArray(data
// @ts-ignore
) {
    return Array.isArray(data);
}
/**
 * Checks if `data` is `object`.
 * @warning This function does not treat `Array` as `object`
 * @param data - Anything
 * @example
 * const item = { data: 1 } as { data: number } | string[]
 * if (P.isObject(item)) {
 *    console.log(item.data)
 * }
 *
 * const items = [{ data: 1 },[],1,4,P.clamp].filter(P.isObject) //=> [{ data: 1 }]
 * @category Guard
 */
export function isObject(data
// @ts-ignore
) {
    return !!data && !Array.isArray(data) && typeof data === 'object';
}
/**
 * Checks if `data` is `function`
 * @param data - Anything
 * @example
 * const item = P.clamp as unknown
 * if (P.isNil(item)) {
 *    // Item is definitely function
 *    console.log('Nice function', item.name)
 * }
 *
 * const items = [1,2,3,4,P.clamp].filter(P.isFunction) //=> [P.clamp]
 * @category Guard
 */
// @ts-ignore
export function isFunction(data) {
    return typeof data === 'function';
}
/**
 * Checks if `data` is `null` or `undefined`. Executes basic `data == null` evaluation
 * @param data - Anything
 * @example
 * const item = undefined as unknown
 * if (P.isNil(item)) {
 *    // Item is definitely null | undefined
 *    console.log('Do something')
 * }
 *
 * const items = [1,2,3,4,undefined].filter(P.isNil) //=> [undefined]
 * @category Guard
 */
export function isNil(data) {
    return data == null;
}
/**
 * Checks if `data` is instance of Error class
 * @param data - Anything
 * @example
 * const item = new Error('Error') as unknown
 * if (P.isError(item)) {
 *    // This is definitely an error and Typescript resolves it
 *    console.log(item.message)
 * }
 *
 * const items = [1,2,3,4,new Error('Error')].filter(P.isError) //=> [new Error('Error')]
 * @category Guard
 */
// @ts-ignore
export function isError(data) {
    return data instanceof Error;
}
export function isNot(predicate) {
    return function (data) {
        return !predicate(data);
    };
}
export function haveKeys(keys) {
    return function (data) {
        return keys.every(function (q) {
            return isDefined(data[q]);
        });
    };
}