URL params serializer; (#4734)

* Refactored BuildURL helper to use URLSearchParams serializer;

* Updated typings;
Added TS test;

test/specs/helpers/buildURL.spec.js

@@ -17,7 +17,7 @@ describe('helpers::buildURL', function () {
       foo: {
         bar: 'baz'
       }
-    })).toEqual('/foo?foo=' + encodeURI('{"bar":"baz"}'));
+    })).toEqual('/foo?foo[bar]=baz');
   });
 
   it('should support date params', function () {
@@ -60,15 +60,6 @@ describe('helpers::buildURL', function () {
     })).toEqual('/foo?foo=bar&query=baz');
   });
 
-  it('should use serializer if provided', function () {
-    serializer = sinon.stub();
-    params = {foo: 'bar'};
-    serializer.returns('foo=bar');
-    expect(buildURL('/foo', params, serializer)).toEqual('/foo?foo=bar');
-    expect(serializer.calledOnce).toBe(true);
-    expect(serializer.calledWith(params)).toBe(true);
-  });
-
   it('should support URLSearchParams', function () {
     expect(buildURL('/foo', new URLSearchParams('bar=baz'))).toEqual('/foo?bar=baz');
   });

test/typescript/axios.ts

@@ -20,7 +20,10 @@ const config: AxiosRequestConfig = {
   ],
   headers: { 'X-FOO': 'bar' },
   params: { id: 12345 },
-  paramsSerializer: (params: any) => 'id=12345',
+  paramsSerializer: {
+    indexes: true,
+    encode: (value) => value
+  },
   data: { foo: 'bar' },
   timeout: 10000,
   withCredentials: true,