Add isPlainObject() method

Author: WezomDev

src/is-plain-object.test.ts

@@ -0,0 +1,92 @@
+// -----------------------------------------------------------------------------
+// Deps
+// -----------------------------------------------------------------------------
+
+import { isPlainObject } from './is-plain-object';
+
+// -----------------------------------------------------------------------------
+// Tests
+// -----------------------------------------------------------------------------
+
+const testCases: {
+	parameters: Parameters<typeof isPlainObject>;
+	result: ReturnType<typeof isPlainObject>;
+}[] = [
+	{
+		parameters: [null],
+		result: false
+	},
+	{
+		parameters: [undefined],
+		result: false
+	},
+	{
+		parameters: ['string'],
+		result: false
+	},
+	{
+		parameters: [new String()],
+		result: true
+	},
+	{
+		parameters: [new Number()],
+		result: true
+	},
+	{
+		parameters: [new Boolean()],
+		result: true
+	},
+	{
+		parameters: [new Function()],
+		result: true
+	},
+	{
+		parameters: [789],
+		result: false
+	},
+	{
+		parameters: [['array']],
+		result: false
+	},
+	{
+		parameters: [new Array(2)],
+		result: false
+	},
+	{
+		parameters: [{}],
+		result: true
+	},
+	{
+		parameters: [
+			{
+				key: 'value'
+			}
+		],
+		result: true
+	},
+	{
+		parameters: [new Object(null)],
+		result: true
+	},
+	{
+		parameters: [new Date()],
+		result: true
+	},
+	{
+		parameters: [new Date()],
+		result: true
+	},
+	{
+		parameters: [new RegExp('x')],
+		result: true
+	}
+];
+
+describe('isPlainObject tool', () => {
+	testCases.forEach(({ parameters, result }, i) => {
+		test(`test #${i + 1}: ${parameters.join(', ')}`, () => {
+			const bool = isPlainObject(...parameters);
+			expect(bool).toStrictEqual(result);
+		});
+	});
+});

src/is-plain-object.ts

@@ -0,0 +1,17 @@
+// -----------------------------------------------------------------------------
+// Deps
+// -----------------------------------------------------------------------------
+
+import { IPlainObject } from './types';
+
+// -----------------------------------------------------------------------------
+// Helper
+// -----------------------------------------------------------------------------
+
+/**
+ * @param sample
+ * @return {boolean}
+ */
+export function isPlainObject<GValue = any>(sample: any): sample is IPlainObject<GValue> {
+	return sample instanceof Object && !Array.isArray(sample);
+}