add is.urlSearchParams

readme.md

@@ -443,6 +443,17 @@ is.formData(data);
 //=> true
 ```
 
+##### .urlSearchParams(value)
+
+Returns `true` if `value` is an instance of the [`URLSearchParams` class](https://developer.mozilla.org/en-US/docs/Web/API/URLSearchParams).
+
+```js
+const data = new URLSearchParams();
+
+is.urlSearchParams(data);
+//=> true
+```
+
 ##### .any(predicate | predicate[], ...values)
 
 Using a single `predicate` argument, returns `true` if **any** of the input `values` returns true in the `predicate`:

source/index.ts

@@ -48,6 +48,7 @@ const objectTypeNames = [
 	'Promise',
 	'URL',
 	'FormData',
+	'URLSearchParams',
 	'HTMLElement',
 	...typedArrayTypeNames
 ] as const;
@@ -365,6 +366,8 @@ is.nonEmptyMap = <Key = unknown, Value = unknown>(value: unknown): value is Map<
 is.propertyKey = (value: unknown): value is PropertyKey => is.any([is.string, is.number, is.symbol], value);
 is.formData = (value: unknown): value is FormData => isObjectOfType<FormData>('FormData')(value);
 
+is.urlSearchParams = (value: unknown): value is URLSearchParams => isObjectOfType<URLSearchParams>('URLSearchParams')(value);
+
 export type Predicate = (value: unknown) => boolean;
 
 type ArrayMethod = (fn: (value: unknown, index: number, array: unknown[]) => boolean, thisArg?: unknown) => boolean;
@@ -526,6 +529,7 @@ interface Assert {
 	nonEmptyMap: <Key = unknown, Value = unknown>(value: unknown) => asserts value is Map<Key, Value>;
 	propertyKey: (value: unknown) => asserts value is PropertyKey;
 	formData: (value: unknown) => asserts value is FormData;
+	urlSearchParams: (value: unknown) => asserts value is URLSearchParams;
 
 	// Numbers.
 	evenInteger: (value: number) => asserts value is number;
@@ -625,6 +629,7 @@ export const assert: Assert = {
 	nonEmptyMap: <Key = unknown, Value = unknown>(value: unknown): asserts value is Map<Key, Value> => assertType(is.nonEmptyMap(value), AssertionTypeDescription.nonEmptyMap, value),
 	propertyKey: (value: unknown): asserts value is number => assertType(is.propertyKey(value), 'PropertyKey', value),
 	formData: (value: unknown): asserts value is FormData => assertType(is.formData(value), 'FormData', value),
+	urlSearchParams: (value: unknown): asserts value is URLSearchParams => assertType(is.urlSearchParams(value), 'URLSearchParams', value),
 
 	// Numbers.
 	evenInteger: (value: number): asserts value is number => assertType(is.evenInteger(value), AssertionTypeDescription.evenInteger, value),

test/test.ts

@@ -1642,6 +1642,27 @@ test('is.formData', t => {
 	});
 });
 
+test('is.urlSearchParams', t => {
+	const params = new window.URLSearchParams();
+	t.true(is.urlSearchParams(params));
+	t.false(is.urlSearchParams({}));
+	t.false(is.urlSearchParams(undefined));
+	t.false(is.urlSearchParams(null));
+
+	t.notThrows(() => {
+		assert.urlSearchParams(params);
+	});
+	t.throws(() => {
+		assert.urlSearchParams({});
+	});
+	t.throws(() => {
+		assert.urlSearchParams(undefined);
+	});
+	t.throws(() => {
+		assert.urlSearchParams(null);
+	});
+});
+
 test('assert', t => {
 	// Contrived test showing that TypeScript acknowledges the type assertion in `assert.number()`.
 	// Real--world usage includes asserting user input, but here we use a random number/string generator.