chore(ui,ui-react-core): Add type guard utils (#3291)

Author: ioanabrooks

.changeset/sixty-buttons-study.md

@@ -0,0 +1,6 @@
+---
+'@aws-amplify/ui-react-core': patch
+'@aws-amplify/ui': patch
+---
+
+chore(ui,ui-react-core): Add type guard utils

packages/react-core/src/Authenticator/hooks/useAuthenticator/utils.ts

@@ -7,8 +7,8 @@ import {
   getSortedFormFields,
   UnverifiedContactMethods,
   getActorContext,
+  isString,
 } from '@aws-amplify/ui';
-import isString from 'lodash/isString';
 
 import { areEmptyArrays, areEmptyObjects } from '../../../utils';
 import { AuthenticatorLegacyField, AuthenticatorLegacyFields } from '../types';

packages/react-core/src/InAppMessaging/utils/handleMessageAction.ts

@@ -1,5 +1,5 @@
 import { ConsoleLogger as Logger } from '@aws-amplify/core';
-import isString from 'lodash/isString';
+import { isString } from '@aws-amplify/ui';
 
 import { MessageAction } from '../types';
 

packages/react-core/src/hooks/useHasValueUpdated.ts

@@ -1,5 +1,6 @@
+import { isUndefined } from '@aws-amplify/ui';
+
 import usePreviousValue from './usePreviousValue';
-import isUndefined from 'lodash/isUndefined';
 
 export default function useHasValueUpdated<Value>(
   value: Value,

packages/react-core/src/utils/index.ts

@@ -1,6 +1,6 @@
 import isEmpty from 'lodash/isEmpty';
-import isObject from 'lodash/isObject';
-import isString from 'lodash/isString';
+
+import { isObject, isString } from '@aws-amplify/ui';
 
 function isEmptyArray<T>(value: T): boolean {
   return Array.isArray(value) && isEmpty(value);
@@ -11,7 +11,7 @@ export function areEmptyArrays<T>(...values: T[]): boolean {
 }
 
 function isEmptyObject<T>(value: T): boolean {
-  return isObject(value) && !Array.isArray(value) && isEmpty(value);
+  return isObject(value) && isEmpty(value);
 }
 
 export function areEmptyObjects<T>(...values: T[]): boolean {

packages/ui/src/index.ts

@@ -3,3 +3,4 @@ export * from './i18n';
 export * from './machines';
 export * from './theme';
 export * from './types';
+export * from './utils';

packages/ui/src/theme/utils.ts

@@ -1,11 +1,10 @@
 import has from 'lodash/has';
-import isObject from 'lodash/isObject';
-import isString from 'lodash/isString';
 import kebabCase from 'lodash/kebabCase';
 
 // internal style dictionary function
 import usesReference from 'style-dictionary/lib/utils/references/usesReference';
 
+import { isObject, isString } from '../utils';
 import {
   DesignToken,
   ShadowValue,

packages/ui/src/utils/__tests__/index.test.ts

@@ -0,0 +1,61 @@
+import { isObject, isString, isUndefined } from '..';
+
+describe('isObject', () => {
+  it('should return `true` for objects', () => {
+    expect(isObject(new Number(0))).toStrictEqual(true);
+    expect(isObject(new String(''))).toStrictEqual(true);
+    expect(isObject(new Date())).toStrictEqual(true);
+    expect(isObject(new Error())).toStrictEqual(true);
+    expect(isObject({})).toStrictEqual(true);
+    expect(isObject({ test: 1 })).toStrictEqual(true);
+    expect(isObject(Object(false))).toStrictEqual(true);
+    expect(isObject(Object(0))).toStrictEqual(true);
+    expect(isObject(Object('test'))).toStrictEqual(true);
+  });
+
+  it('should return `false` for non-objects', () => {
+    expect(isObject(null)).toStrictEqual(false);
+    expect(isObject(undefined)).toStrictEqual(false);
+    expect(isObject(true)).toStrictEqual(false);
+    expect(isObject(0)).toStrictEqual(false);
+    expect(isObject('test')).toStrictEqual(false);
+    expect(isObject([1, 2, 3])).toStrictEqual(false);
+    expect(isObject(() => {})).toStrictEqual(false);
+  });
+});
+
+describe('isString', () => {
+  it('should return `true` for strings', () => {
+    expect(isString('')).toStrictEqual(true);
+    expect(isString('test')).toStrictEqual(true);
+    expect(isString(new String('test'))).toStrictEqual(true);
+  });
+
+  it('should return `false` for non-strings', () => {
+    expect(isString(null)).toStrictEqual(false);
+    expect(isString(undefined)).toStrictEqual(false);
+    expect(isString(true)).toStrictEqual(false);
+    expect(isString(0)).toStrictEqual(false);
+    expect(isString([1, 2, 3])).toStrictEqual(false);
+  });
+});
+
+describe('isUndefined', () => {
+  it('should return `true` for undefined values', function () {
+    expect(isUndefined(undefined)).toStrictEqual(true);
+    expect(isUndefined(void 0)).toStrictEqual(true);
+  });
+
+  it('should return `false` for non-undefined values', function () {
+    expect(isUndefined(null)).toStrictEqual(false);
+    expect(isUndefined(true)).toStrictEqual(false);
+    expect(isUndefined('')).toStrictEqual(false);
+    expect(isUndefined(0)).toStrictEqual(false);
+    expect(isUndefined([1, 2, 3])).toStrictEqual(false);
+    expect(isUndefined(new Number(0))).toStrictEqual(false);
+    expect(isUndefined(new String(''))).toStrictEqual(false);
+    expect(isUndefined(new Date())).toStrictEqual(false);
+    expect(isUndefined(new Error())).toStrictEqual(false);
+    expect(isUndefined({})).toStrictEqual(false);
+  });
+});

packages/ui/src/utils/index.ts

@@ -0,0 +1,35 @@
+/**
+ * Checks if `value` is an Object (non-primitive, non-array, non-function)
+ * Will return false for Arrays and functions
+ *
+ *
+ * @param {unknown} value The value to check
+ * @returns {boolean} Returns `true` if `value` is an object, `false` otherwise
+ */
+export function isObject(value: unknown): value is object {
+  return value != null && !Array.isArray(value) && typeof value === 'object';
+}
+
+/**
+ * Checks if `value` is a string primitive or object
+ *
+ * @param {unknown} value The value to check
+ * @returns {boolean} Returns `true` if `value` is a string, `false` otherwise
+ */
+export function isString(value: unknown): value is string {
+  return (
+    typeof value === 'string' ||
+    (typeof value === 'object' &&
+      Object.prototype.toString.call(value) === '[object String]')
+  );
+}
+
+/**
+ * Checks if `value` is undefined
+ *
+ * @param {unknown} value The value to check
+ * @returns {boolean} Returns `true` if `value` is undefined, `false` otherwise
+ */
+export function isUndefined(value: unknown): value is undefined {
+  return value === undefined;
+}