feat: add functions with the types and tests

+ `isDate()`
+ `isFalse()`
+ `isNumberBetween()`
+ `isRegExp()`
+ `isStringLength()`
+ `isTrue()`
+ constants for date
+ constant for `RegExp`
+ update api

src/is/index.ts

@@ -5,23 +5,29 @@ export { isBoolean } from './lib/is-boolean.func';
 export { isBooleanObject } from './lib/is-boolean-object.func';
 export { isBooleanType } from './lib/is-boolean-type.func';
 export { isClass } from './lib/is-class.func';
+export { isDate } from './lib/is-date.func'; // From 4.2.0
 export { isDefined } from './lib/is-defined.func';
+export { isFalse } from './lib/is-false.func'; // From 4.2.0
 export { isFunction } from './lib/is-function.func';
 export { isInstance } from './lib/is-instance.func';
 export { isKey } from './lib/is-key.func';
 export { isNull } from './lib/is-null.func';
 export { isNumber } from './lib/is-number.func';
+export { isNumberBetween } from './lib/is-number-between.func'; // From 4.2.0
 export { isNumberObject } from './lib/is-number-object.func';
 export { isNumberType } from './lib/is-number-type.func';
 export { isObject } from './lib/is-object.func';
 export { isObjectKey } from './lib/is-object-key.func';
 export { isObjectKeyIn } from './lib/is-object-key-in.func';
 export { isObjectKeys } from './lib/is-object-keys.func';
 export { isPrimitive } from './lib/is-primitive.func';
+export { isRegExp } from './lib/is-regexp.func'; // From 4.2.0
 export { isString } from './lib/is-string.func';
+export { isStringLength } from './lib/is-string-length.func'; // From 4.2.0
 export { isStringObject } from './lib/is-string-object.func';
 export { isStringType } from './lib/is-string-type.func';
 export { isSymbol } from './lib/is-symbol.func';
+export { isTrue } from './lib/is-true.func'; // From 4.2.0
 export { isType } from './lib/is-type.func';
 export { isUndefined } from './lib/is-undefined.func';
 // `is` object.

src/is/interface/is.interface.ts

@@ -1,30 +1,38 @@
+// Import: Type.
 import { IsArray } from '../type/is-array.type';
 import { IsBigInt } from '../type/is-big-int.type';
 import { IsBoolean } from '../type/is-boolean.type';
 import { IsBooleanObject } from '../type/is-boolean-object.type';
 import { IsBooleanType } from '../type/is-boolean-type.type';
 import { IsClass } from '../type/is-class.type';
+import { IsDate } from '../type/is-date.type';
 import { IsDefined } from '../type/is-defined.type';
+import { IsFalse } from '../type/is-false.type';
 import { IsFunction } from '../type/is-function.type';
 import { IsInstance } from '../type/is-instance.type';
 import { IsKey } from '../type/is-key.type';
 import { IsNot } from '../not/interface/is-not.interface';
 import { IsNull } from '../type/is-null.type';
 import { IsNumber } from '../type/is-number.type';
+import { IsNumberBetween } from '../type/is-number-between.type';
 import { IsNumberObject } from '../type/is-number-object.type';
 import { IsNumberType } from '../type/is-number-type.type';
 import { IsObject } from '../type/is-object.type';
 import { IsObjectKey } from '../type/is-object-key.type';
 import { IsObjectKeyIn } from '../type/is-object-key-in.type';
 import { IsObjectKeys } from '../type/is-object-keys.type';
 import { IsPrimitive } from '../type/is-primitive.type';
+import { IsRegExp } from '../type/is-regexp.type';
 import { IsString } from '../type/is-string.type';
+import { IsStringLength } from '../type/is-string-length.type';
 import { IsStringObject } from '../type/is-string-object.type';
 import { IsStringType } from '../type/is-string-type.type';
 import { IsSymbol } from '../type/is-symbol.type';
+import { IsTrue } from '../type/is-true.type';
 import { IsType } from '../type/is-type.type';
 import { IsUndefined } from '../type/is-undefined.type';
 /**
+ * Export: Interface.
  * Object with prefixed `is` functions.
  */
 export interface Is {
@@ -35,24 +43,30 @@ export interface Is {
   booleanObject: IsBooleanObject;
   booleanType: IsBooleanType;
   class: IsClass;
+  date: IsDate; // From 4.2.0
   defined: IsDefined;
+  false: IsFalse; // From `4.2.0`
   function: IsFunction;
   instance: IsInstance;
   key: IsKey;
   not: IsNot;
   null: IsNull;
   number: IsNumber;
+  numberBetween: IsNumberBetween; // From `4.2.0`
   numberObject: IsNumberObject;
   numberType: IsNumberType;
   object: IsObject;
   objectKey: IsObjectKey;
   objectKeyIn: IsObjectKeyIn;
   objectKeys: IsObjectKeys;
   primitive: IsPrimitive;
+  regexp: IsRegExp; // From 4.2.0
   string: IsString;
+  stringLength: IsStringLength;
   stringObject: IsStringObject;
   stringType: IsStringType;
   symbol: IsSymbol;
+  true: IsTrue; // From 4.2.0
   type: IsType;
   undefined: IsUndefined;
 }

src/is/lib/is-date.func.ts

@@ -0,0 +1,23 @@
+// Function.
+import { typeOf } from '../../lib/type-of.func';
+import { resultCallback } from '../../lib/result-callback.func';
+// Type.
+import { IsDate } from '../type/is-date.type';
+import { ResultCallback } from '../../type/result-callback.type';
+/**
+ * Checks if any `value` is an `object` type instance of `Date` and `Object`.
+ * @param value Any `value` to check.
+ * @param callback An optional `ResultCallback` function to handle the result before returns.
+ * @returns A `boolean` indicating whether or not the value is a date.
+ */
+export const isDate: IsDate = (
+  value: any,
+  callback: ResultCallback = resultCallback
+): value is Date =>
+  callback(
+    typeOf(value) === 'date' &&
+    typeof value === 'object' &&
+    value instanceof Date === true &&
+    value instanceof Object === true,
+    value
+  );

src/is/lib/is-false.func.ts

@@ -0,0 +1,24 @@
+// Function.
+import { isBooleanObject } from './is-boolean-object.func';
+import { isBooleanType } from './is-boolean-type.func';
+import { resultCallback } from '../../lib/result-callback.func';
+// Type.
+import { IsFalse } from '../type/is-false.type';
+import { ResultCallback } from '../../type/result-callback.type';
+/**
+ * Checks if any `value` is a `boolean` type not an instance of `Boolean` and `Object`, or
+ * is an `object` type and instance of `Boolean` and `Object` and equal to `false`.
+ * @param value Any `value` to check.
+ * @param callback A `ResultCallback` function to handle the result before returns.
+ * @returns A `boolean` indicating whether or not the `value` is a `boolean` equal to `false`.
+ */
+export const isFalse: IsFalse = (
+  value: any,
+  callback: ResultCallback = resultCallback
+): value is false =>
+  callback(
+    (isBooleanType(value) && value === false)
+    ||
+    (isBooleanObject(value) && value.valueOf() === false),
+    value
+  );

src/is/lib/is-number-between.func.ts

@@ -0,0 +1,32 @@
+// Function.
+import { isNumberObject } from './is-number-object.func';
+import { isNumberType } from './is-number-type.func';
+import { resultCallback } from '../../lib/result-callback.func';
+import { typeOf } from '../../lib/type-of.func';
+// Type.
+import { NumberBetween } from '../../type/number-between.type';
+import { ResultCallback } from '../../type/result-callback.type';
+/**
+ * Checks if any `value` is a `number` type, not instance of `Object` and `Number` or `object` type and instance of `Number` and `Object`,
+ * in the specified range.
+ * @param value Any `value` to check.
+ * @param min A `number` of the minimum range of the provided `value`.
+ * @param max A `number` of the maximum range of the provided `value`.
+ * @param callback A `ResultCallback` function to handle the result before returns.
+ * @returns A `boolean` indicating whether or not the `value` is a `number` type or `Number` instance in the specified range.
+ */
+export const isNumberBetween = <Min extends number, Max extends number>(
+  value: any,
+  min: Min,
+  max: Max,
+  callback: ResultCallback = resultCallback
+): value is NumberBetween<Min, Max> => {
+  return callback(
+    typeOf(value) === 'number' &&
+      ((isNumberType(value) ? value >= min && value <= max : false) ||
+        (isNumberObject(value)
+          ? value.valueOf() >= min && value.valueOf() <= max
+          : false)),
+    value
+  );
+};

src/is/lib/is-object-keys-type.func.ts

@@ -0,0 +1,47 @@
+// Function.
+import { isArray } from './is-array.func';
+import { isKey } from './is-key.func';
+// Type.
+import { IsObjectKeys } from '../type/is-object-keys.type';
+import { isObject } from './is-object.func';
+import { Types } from '../../type/types.type';
+import { Func } from '../../type/func.type';
+import { isType } from './is-type.func';
+import { Primitives } from '../../type/primitives.type';
+import { isPrimitive } from './is-primitive.func';
+import { guardPrimitive } from '../../guard/lib/guard-primitive.func';
+
+type IsObjectKeysType =
+<Type extends object>(...keys: (keyof Type)[]
+) => (...type: Primitives[]) => (value: Type) => value is Type;
+
+/**
+ * Checks if any `value` is an `object` of a generic `Type` with some of its own specified `keys`.
+ * @param value Any `value` to check if it contains some of the specified `keys`.
+ * @param keys A rest parameter key of `Type` or an array of keys of `Type` to check the `value`.
+ * @returns A `boolean` indicating whether or not the `value` is an `object` with some of its own specified keys.
+ */
+export const isObjectKeysType: IsObjectKeysType =
+  <Type extends object>(...keys: (keyof Type | Array<keyof Type>)[]) =>
+  (...type: Primitives[]) =>
+  (value: any): value is Type =>
+    isObject<Type>(value)
+    ? keys.some((key, keysIndex: number) =>
+      isArray(key)
+        ? key.every((k, arrIndex: number) =>
+          isKey(k) ? {}.hasOwnProperty.call(value, k) === true ? isPrimitive(value[k], type[arrIndex]) : false : false
+        )
+        : isKey(key)
+          ? {}.hasOwnProperty.call(value, key) === true ? isPrimitive(value[key], type[keysIndex]) : false
+          : false
+    )
+    : false;
+
+class Person {
+  firstName = 'bla';
+  surname = 'bla bla bla';
+}
+
+const person: Person = new Person();
+
+isObjectKeysType<Person>('firstName')('string')(person);

src/is/lib/is-regexp.func.ts

@@ -0,0 +1,22 @@
+// Import: Function.
+import { resultCallback } from '../../lib/result-callback.func';
+import { typeOf } from '../../lib/type-of.func';
+// Import: Type.
+import { IsRegExp } from '../type/is-regexp.type';
+import { ResultCallback } from '../../type/result-callback.type';
+/**
+ * Checks if any `value` is a `regexp` type, an instance of `Object` and `RegExp`.
+ * @param value Any `value` to check.
+ * @param callback An optional `ResultCallback` function to handle the result before returns.
+ * @returns A `boolean` indicating whether or not the `value` is a regular expression.
+ */
+export const isRegExp: IsRegExp = (
+  value: any,
+  callback: ResultCallback = resultCallback
+): value is RegExp =>
+  callback(
+    typeOf(value) === 'regexp' &&
+      typeof value === 'object' &&
+      value instanceof Object &&
+      value instanceof RegExp
+  );

src/is/lib/is-string-length.func.ts

@@ -0,0 +1,37 @@
+// Function.
+import { isStringObject } from './is-string-object.func';
+import { isStringType } from './is-string-type.func';
+import { resultCallback } from '../../lib/result-callback.func';
+import { typeOf } from '../../lib/type-of.func';
+// Type.
+import { IsStringLength } from '../type/is-string-length.type';
+import { ResultCallback } from '../../type/result-callback.type';
+import { StringOfLength } from '../../type/string-of-length.type';
+/**
+ * Checks if any `value` is a `string` type, not instance of `Object` and `String` or `object` type and instance of `String` and `Object`,
+ * of a length in the specified range.
+ * @param value Any `value` to check.
+ * @param min A `number` of the minimum length of the provided `value`.
+ * @param max A `number` of the maximum length of the provided `value`.
+ * @param callback A `ResultCallback` function to handle the result before returns.
+ * @returns A `boolean` indicating whether or not the `value` is a `string` type or `String` instance of length in the specified range.
+ */
+export const isStringLength: IsStringLength = <
+  Min extends number,
+  Max extends number
+>(
+  value: any,
+  min: Min,
+  max: Max,
+  callback: ResultCallback = resultCallback
+): value is StringOfLength<Min, Max> =>
+  callback(
+    typeOf(value) === 'string' &&
+      ((isStringType(value)
+        ? value.length >= min && value.length <= max
+        : false) ||
+        (isStringObject(value)
+          ? value.valueOf().length >= min && value.valueOf().length <= max
+          : false)),
+    value
+  );

src/is/lib/is-true.func.ts

@@ -0,0 +1,24 @@
+// Function.
+import { isBooleanObject } from './is-boolean-object.func';
+import { isBooleanType } from './is-boolean-type.func';
+import { resultCallback } from '../../lib/result-callback.func';
+// Type.
+import { IsTrue } from '../type/is-true.type';
+import { ResultCallback } from '../../type/result-callback.type';
+/**
+ * Checks if any `value` is a `boolean` type not an instance of `Boolean` and `Object`, or
+ * is an `object` type and instance of `Boolean` and `Object` and equal to `true`.
+ * @param value Any `value` to check.
+ * @param callback A `ResultCallback` function to handle the result before returns.
+ * @returns A `boolean` indicating whether or not the `value` is a `boolean` equal to `true`.
+ */
+export const isTrue: IsTrue = (
+  value: any,
+  callback: ResultCallback = resultCallback
+): value is true =>
+  callback(
+    (isBooleanType(value) && value === true)
+    ||
+    (isBooleanObject(value) && value.valueOf() === true),
+    value
+  );

src/is/lib/is.object.ts

@@ -1,34 +1,40 @@
-// Function.
+// Import: Function.
 import { isArray } from './is-array.func';
 import { isBigInt } from './is-big-int.func';
 import { isBoolean } from './is-boolean.func';
 import { isBooleanObject } from './is-boolean-object.func';
 import { isBooleanType } from './is-boolean-type.func';
 import { isClass } from './is-class.func';
+import { isDate } from './is-date.func';
 import { isDefined } from './is-defined.func';
+import { isFalse } from './is-false.func';
 import { isFunction } from './is-function.func';
 import { isInstance } from './is-instance.func';
 import { isKey } from './is-key.func';
 import { isNull } from './is-null.func';
 import { isNumber } from './is-number.func';
+import { isNumberBetween } from './is-number-between.func';
 import { isNumberObject } from './is-number-object.func';
 import { isNumberType } from './is-number-type.func';
 import { isObject } from './is-object.func';
 import { isObjectKey } from './is-object-key.func';
 import { isObjectKeyIn } from './is-object-key-in.func';
 import { isObjectKeys } from './is-object-keys.func';
 import { isPrimitive } from './is-primitive.func';
+import { isRegExp } from './is-regexp.func';
 import { isString } from './is-string.func';
+import { isStringLength } from './is-string-length.func';
 import { isStringObject } from './is-string-object.func';
 import { isStringType } from './is-string-type.func';
 import { isSymbol } from './is-symbol.func';
 import { isType } from './is-type.func';
 import { isUndefined } from './is-undefined.func';
-// Object.
+// Import: Object.
 import { isNot } from '../not/lib/is-not.object';
-// Interface.
+// Import: Interface.
 import { Is } from '../interface/is.interface';
-// `is`.
+import { isTrue } from './is-true.func';
+// Export: `is`.
 export const is: Is = {
   array: isArray,
   bigInt: isBigInt, // deprecated
@@ -37,24 +43,30 @@ export const is: Is = {
   booleanObject: isBooleanObject,
   booleanType: isBooleanType,
   class: isClass,
+  date: isDate, // From `4.2.0`
   defined: isDefined,
+  false: isFalse, // From `4.2.0`
   function: isFunction,
   instance: isInstance,
   key: isKey,
   not: isNot,
   null: isNull,
   number: isNumber,
+  numberBetween: isNumberBetween, // From `4.2.0`
   numberObject: isNumberObject,
   numberType: isNumberType,
   object: isObject,
   objectKey: isObjectKey,
   objectKeyIn: isObjectKeyIn,
   objectKeys: isObjectKeys,
   primitive: isPrimitive,
+  regexp: isRegExp, // From `4.2.0`
   string: isString,
+  stringLength: isStringLength, // From `4.2.0`
   stringObject: isStringObject,
   stringType: isStringType,
   symbol: isSymbol,
+  true: isTrue, // From `4.2.0`
   type: isType,
   undefined: isUndefined
 };