feat: added custom params serializer support; (#5113)

* Added custom params serializer support;

* Added missed semicolon;
Fixed allowUnknown option;

Co-authored-by: Jay <jasonsaayman@gmail.com>

test/specs/helpers/buildURL.spec.js

@@ -63,4 +63,20 @@ describe('helpers::buildURL', function () {
   it('should support URLSearchParams', function () {
     expect(buildURL('/foo', new URLSearchParams('bar=baz'))).toEqual('/foo?bar=baz');
   });
+
+  it('should support custom serialize function', function () {
+    const params = {
+      x: 1
+    }
+
+    const options = {
+      serialize: (thisParams, thisOptions) => {
+        expect(thisParams).toEqual(params);
+        expect(thisOptions).toEqual(options);
+        return "rendered"
+      }
+    };
+
+    expect(buildURL('/foo', params, options)).toEqual('/foo?rendered');
+  });
 });

test/typescript/axios.ts

@@ -21,7 +21,8 @@ const config: AxiosRequestConfig = {
   params: { id: 12345 },
   paramsSerializer: {
     indexes: true,
-    encode: (value) => value
+    encode: (value) => value,
+    serialize: (value, options) => String(value)
   },
   data: { foo: 'bar' },
   timeout: 10000,