/// /// /// /// // TODO: Use the `URL` global when targeting Node.js 10 // tslint:disable-next-line const URLGlobal = typeof URL === 'undefined' ? require('url').URL : URL; type TypedArray = Int8Array | Uint8Array | Uint8ClampedArray | Int16Array | Uint16Array | Int32Array | Uint32Array | Float32Array | Float64Array; type Primitive = null | undefined | string | number | boolean | Symbol; export interface ArrayLike { length: number; } export type Class = new(...args: any[]) => T; type DomElement = object & { nodeType: 1; nodeName: string }; type NodeStream = object & { pipe: Function }; export const enum TypeName { null = 'null', boolean = 'boolean', undefined = 'undefined', string = 'string', number = 'number', symbol = 'symbol', Function = 'Function', GeneratorFunction = 'GeneratorFunction', AsyncFunction = 'AsyncFunction', Observable = 'Observable', Array = 'Array', Buffer = 'Buffer', Object = 'Object', RegExp = 'RegExp', Date = 'Date', Error = 'Error', Map = 'Map', Set = 'Set', WeakMap = 'WeakMap', WeakSet = 'WeakSet', Int8Array = 'Int8Array', Uint8Array = 'Uint8Array', Uint8ClampedArray = 'Uint8ClampedArray', Int16Array = 'Int16Array', Uint16Array = 'Uint16Array', Int32Array = 'Int32Array', Uint32Array = 'Uint32Array', Float32Array = 'Float32Array', Float64Array = 'Float64Array', ArrayBuffer = 'ArrayBuffer', SharedArrayBuffer = 'SharedArrayBuffer', DataView = 'DataView', Promise = 'Promise', URL = 'URL' } const toString = Object.prototype.toString; const isOfType = (type: string) => (value: unknown): value is T => typeof value === type; const isBuffer = (input: unknown): input is Buffer => !is.nullOrUndefined(input) && !is.nullOrUndefined((input as Buffer).constructor) && is.function_((input as Buffer).constructor.isBuffer) && (input as Buffer).constructor.isBuffer(input); const getObjectType = (value: unknown): TypeName | null => { const objectName = toString.call(value).slice(8, -1); if (objectName) { return objectName as TypeName; } return null; }; const isObjectOfType = (type: TypeName) => (value: unknown): value is T => getObjectType(value) === type; function is(value: unknown): TypeName { // tslint:disable-line:only-arrow-functions switch (value) { case null: return TypeName.null; case true: case false: return TypeName.boolean; default: } switch (typeof value) { case 'undefined': return TypeName.undefined; case 'string': return TypeName.string; case 'number': return TypeName.number; case 'symbol': return TypeName.symbol; default: } if (is.function_(value)) { return TypeName.Function; } if (is.observable(value)) { return TypeName.Observable; } if (Array.isArray(value)) { return TypeName.Array; } if (isBuffer(value)) { return TypeName.Buffer; } const tagType = getObjectType(value); if (tagType) { return tagType; } if (value instanceof String || value instanceof Boolean || value instanceof Number) { throw new TypeError('Please don\'t use object wrappers for primitive types'); } return TypeName.Object; } // tslint:disable-next-line:strict-type-predicates const isObject = (value: unknown): value is object => typeof value === 'object'; is.undefined = isOfType('undefined'); is.string = isOfType('string'); is.number = isOfType('number'); is.function_ = isOfType('function'); // tslint:disable-next-line:strict-type-predicates is.null_ = (value: unknown): value is null => value === null; is.class_ = (value: unknown): value is Class => is.function_(value) && value.toString().startsWith('class '); is.boolean = (value: unknown): value is boolean => value === true || value === false; is.symbol = isOfType('symbol'); // tslint:enable:variable-name is.numericString = (value: unknown): boolean => is.string(value) && value.length > 0 && !Number.isNaN(Number(value)); is.array = Array.isArray; is.buffer = isBuffer; is.nullOrUndefined = (value: unknown): value is null | undefined => is.null_(value) || is.undefined(value); is.object = (value: unknown): value is object => !is.nullOrUndefined(value) && (is.function_(value) || isObject(value)); is.iterable = (value: unknown): value is IterableIterator => !is.nullOrUndefined(value) && is.function_((value as IterableIterator)[Symbol.iterator]); is.asyncIterable = (value: unknown): value is AsyncIterableIterator => !is.nullOrUndefined(value) && is.function_((value as AsyncIterableIterator)[Symbol.asyncIterator]); is.generator = (value: unknown): value is Generator => is.iterable(value) && is.function_(value.next) && is.function_(value.throw); is.nativePromise = (value: unknown): value is Promise => isObjectOfType>(TypeName.Promise)(value); const hasPromiseAPI = (value: unknown): value is Promise => !is.null_(value) && isObject(value) as unknown && is.function_((value as Promise).then) && is.function_((value as Promise).catch); is.promise = (value: unknown): value is Promise => is.nativePromise(value) || hasPromiseAPI(value); is.generatorFunction = isObjectOfType(TypeName.GeneratorFunction); is.asyncFunction = isObjectOfType(TypeName.AsyncFunction); is.boundFunction = (value: unknown): value is Function => is.function_(value) && !value.hasOwnProperty('prototype'); is.regExp = isObjectOfType(TypeName.RegExp); is.date = isObjectOfType(TypeName.Date); is.error = isObjectOfType(TypeName.Error); is.map = (value: unknown): value is Map => isObjectOfType>(TypeName.Map)(value); is.set = (value: unknown): value is Set => isObjectOfType>(TypeName.Set)(value); is.weakMap = (value: unknown): value is WeakMap => isObjectOfType>(TypeName.WeakMap)(value); is.weakSet = (value: unknown): value is WeakSet => isObjectOfType>(TypeName.WeakSet)(value); is.int8Array = isObjectOfType(TypeName.Int8Array); is.uint8Array = isObjectOfType(TypeName.Uint8Array); is.uint8ClampedArray = isObjectOfType(TypeName.Uint8ClampedArray); is.int16Array = isObjectOfType(TypeName.Int16Array); is.uint16Array = isObjectOfType(TypeName.Uint16Array); is.int32Array = isObjectOfType(TypeName.Int32Array); is.uint32Array = isObjectOfType(TypeName.Uint32Array); is.float32Array = isObjectOfType(TypeName.Float32Array); is.float64Array = isObjectOfType(TypeName.Float64Array); is.arrayBuffer = isObjectOfType(TypeName.ArrayBuffer); is.sharedArrayBuffer = isObjectOfType(TypeName.SharedArrayBuffer); is.dataView = isObjectOfType(TypeName.DataView); is.directInstanceOf = (instance: unknown, klass: Class): instance is T => Object.getPrototypeOf(instance) === klass.prototype; is.urlInstance = (value: unknown): value is URL => isObjectOfType(TypeName.URL)(value); is.urlString = (value: unknown) => { if (!is.string(value)) { return false; } try { new URLGlobal(value); // tslint:disable-line no-unused-expression return true; } catch { return false; } }; is.truthy = (value: unknown) => Boolean(value); is.falsy = (value: unknown) => !value; is.nan = (value: unknown) => Number.isNaN(value as number); const primitiveTypes = new Set([ 'undefined', 'string', 'number', 'boolean', 'symbol' ]); is.primitive = (value: unknown): value is Primitive => is.null_(value) || primitiveTypes.has(typeof value); is.integer = (value: unknown): value is number => Number.isInteger(value as number); is.safeInteger = (value: unknown): value is number => Number.isSafeInteger(value as number); is.plainObject = (value: unknown) => { // From: https://github.com/sindresorhus/is-plain-obj/blob/master/index.js let prototype; return getObjectType(value) === TypeName.Object && (prototype = Object.getPrototypeOf(value), prototype === null || // tslint:disable-line:ban-comma-operator prototype === Object.getPrototypeOf({})); }; const typedArrayTypes = new Set([ TypeName.Int8Array, TypeName.Uint8Array, TypeName.Uint8ClampedArray, TypeName.Int16Array, TypeName.Uint16Array, TypeName.Int32Array, TypeName.Uint32Array, TypeName.Float32Array, TypeName.Float64Array ]); is.typedArray = (value: unknown): value is TypedArray => { const objectType = getObjectType(value); if (objectType === null) { return false; } return typedArrayTypes.has(objectType); }; const isValidLength = (value: unknown) => is.safeInteger(value) && value > -1; is.arrayLike = (value: unknown): value is ArrayLike => !is.nullOrUndefined(value) && !is.function_(value) && isValidLength((value as ArrayLike).length); is.inRange = (value: number, range: number | number[]) => { if (is.number(range)) { return value >= Math.min(0, range) && value <= Math.max(range, 0); } if (is.array(range) && range.length === 2) { return value >= Math.min(...range) && value <= Math.max(...range); } throw new TypeError(`Invalid range: ${JSON.stringify(range)}`); }; const NODE_TYPE_ELEMENT = 1; const DOM_PROPERTIES_TO_CHECK = [ 'innerHTML', 'ownerDocument', 'style', 'attributes', 'nodeValue' ]; is.domElement = (value: unknown): value is DomElement => is.object(value) && (value as DomElement).nodeType === NODE_TYPE_ELEMENT && is.string((value as DomElement).nodeName) && !is.plainObject(value) && DOM_PROPERTIES_TO_CHECK.every(property => property in (value as DomElement)); is.observable = (value: unknown) => { if (!value) { return false; } if ((value as any)[Symbol.observable] && value === (value as any)[Symbol.observable]()) { return true; } if ((value as any)['@@observable'] && value === (value as any)['@@observable']()) { return true; } return false; }; is.nodeStream = (value: unknown): value is NodeStream => !is.nullOrUndefined(value) && isObject(value) as unknown && is.function_((value as NodeStream).pipe) && !is.observable(value); is.infinite = (value: unknown) => value === Infinity || value === -Infinity; const isAbsoluteMod2 = (rem: number) => (value: number) => is.integer(value) && Math.abs(value % 2) === rem; is.even = isAbsoluteMod2(0); is.odd = isAbsoluteMod2(1); const isWhiteSpaceString = (value: unknown) => is.string(value) && /\S/.test(value) === false; is.emptyArray = (value: unknown) => is.array(value) && value.length === 0; is.nonEmptyArray = (value: unknown) => is.array(value) && value.length > 0; is.emptyString = (value: unknown) => is.string(value) && value.length === 0; is.nonEmptyString = (value: unknown) => is.string(value) && value.length > 0; is.emptyStringOrWhitespace = (value: unknown) => is.emptyString(value) || isWhiteSpaceString(value); is.emptyObject = (value: unknown) => is.object(value) && !is.map(value) && !is.set(value) && Object.keys(value).length === 0; is.nonEmptyObject = (value: unknown) => is.object(value) && !is.map(value) && !is.set(value) && Object.keys(value).length > 0; is.emptySet = (value: unknown) => is.set(value) && value.size === 0; is.nonEmptySet = (value: unknown) => is.set(value) && value.size > 0; is.emptyMap = (value: unknown) => is.map(value) && value.size === 0; is.nonEmptyMap = (value: unknown) => is.map(value) && value.size > 0; type ArrayMethod = (fn: (value: unknown, index: number, array: unknown[]) => boolean, thisArg?: unknown) => boolean; const predicateOnArray = (method: ArrayMethod, predicate: unknown, values: unknown[]) => { if (is.function_(predicate) === false) { throw new TypeError(`Invalid predicate: ${JSON.stringify(predicate)}`); } if (values.length === 0) { throw new TypeError('Invalid number of values'); } return method.call(values, predicate as any); }; // tslint:disable variable-name is.any = (predicate: unknown, ...values: unknown[]) => predicateOnArray(Array.prototype.some, predicate, values); is.all = (predicate: unknown, ...values: unknown[]) => predicateOnArray(Array.prototype.every, predicate, values); // tslint:enable variable-name // Some few keywords are reserved, but we'll populate them for Node.js users // See https://github.com/Microsoft/TypeScript/issues/2536 Object.defineProperties(is, { class: { value: is.class_ }, function: { value: is.function_ }, null: { value: is.null_ } }); export default is; // For CommonJS default export support module.exports = is; module.exports.default = is;