feat(common): add URLSearchParams to request body

packages/common/http/src/request.ts

@@ -68,6 +68,15 @@ function isFormData(value: any): value is FormData {
   return typeof FormData !== 'undefined' && value instanceof FormData;
 }
 
+/**
+ * Safely assert whether the given value is a URLSearchParams instance.
+ *
+ * In some execution environments URLSearchParams is not defined.
+ */
+function isUrlSearchParams(value: any): value is URLSearchParams {
+  return typeof URLSearchParams !== 'undefined' && value instanceof URLSearchParams;
+}
+
 /**
  * An outgoing HTTP request with an optional typed body.
  *
@@ -273,7 +282,7 @@ export class HttpRequest<T> {
     // Check whether the body is already in a serialized form. If so,
     // it can just be returned directly.
     if (isArrayBuffer(this.body) || isBlob(this.body) || isFormData(this.body) ||
-        typeof this.body === 'string') {
+        isUrlSearchParams(this.body) || typeof this.body === 'string') {
       return this.body;
     }
     // Check whether the body is an instance of HttpUrlEncodedParams.

packages/common/http/test/request_spec.ts

@@ -143,6 +143,10 @@ const TEST_STRING = `I'm a body!`;
         const body = new ArrayBuffer(4);
         expect(baseReq.clone({body}).serializeBody()).toBe(body);
       });
+      it('passes URLSearchParams through', () => {
+        const body = new URLSearchParams('foo=1&bar=2');
+        expect(baseReq.clone({body}).serializeBody()).toBe(body);
+      });
       it('passes strings through', () => {
         const body = 'hello world';
         expect(baseReq.clone({body}).serializeBody()).toBe(body);