Fix: Don't add null values to query string. (#5108)

* feat: add  boolean flag to mimic pre 1.x behavior for paramsSerializer custom function

* chore: update ParamsSerializer Readme

* fix: dont slice hash off URL if not appending params

* Omit nulls from formData serialization

* fix: dont add nulls or undefined values to arrays either

* readme update

* fix test

* chore: documentation

* chore: do TS properly

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

lib/helpers/buildURL.js

@@ -35,13 +35,7 @@ export default function buildURL(url, params, options) {
   if (!params) {
     return url;
   }
-
-  const hashmarkIndex = url.indexOf('#');
-
-  if (hashmarkIndex !== -1) {
-    url = url.slice(0, hashmarkIndex);
-  }
-
+  
   const _encode = options && options.encode || encode;
 
   const serializeFn = options && options.serialize;
@@ -57,6 +51,11 @@ export default function buildURL(url, params, options) {
   }
 
   if (serializedParams) {
+    const hashmarkIndex = url.indexOf("#");
+
+    if (hashmarkIndex !== -1) {
+      url = url.slice(0, hashmarkIndex);
+    }
     url += (url.indexOf('?') === -1 ? '?' : '&') + serializedParams;
   }
 

lib/helpers/toFormData.js

@@ -168,7 +168,7 @@ function toFormData(obj, formData, options) {
         key = removeBrackets(key);
 
         arr.forEach(function each(el, index) {
-          !utils.isUndefined(el) && formData.append(
+          !(utils.isUndefined(el) || el === null) && formData.append(
             // eslint-disable-next-line no-nested-ternary
             indexes === true ? renderKey([key], index, dots) : (indexes === null ? key : key + '[]'),
             convertValue(el)
@@ -205,7 +205,7 @@ function toFormData(obj, formData, options) {
     stack.push(value);
 
     utils.forEach(value, function each(el, key) {
-      const result = !utils.isUndefined(el) && visitor.call(
+      const result = !(utils.isUndefined(el) || el === null) && visitor.call(
         formData, el, utils.isString(key) ? key.trim() : key, path, exposedHelpers
       );