fix: empty file tags cause upload error for some providers (#7300)

* fix: empty file tags cause upload error for some providers

DigitalOcean and Linode object storage solutions do not accept `tags` option while uploading a file. Previously, tags option was set to default empty object. Now, we do not include it if it is empty.

* chore: add tests for saving a file with/without tags

* chore: update file tags handling to make tests pass

* chore: refactor file tag tests

* chore: update file tag tests

* chore: update changelog

* chore: update changelog entry

* chore: remove duplicated changelog entry

spec/ParseFile.spec.js

@@ -3,6 +3,7 @@
 
 'use strict';
 
+const { FilesController } = require('../lib/Controllers/FilesController');
 const request = require('../lib/request');
 
 const str = 'Hello World!';
@@ -205,6 +206,34 @@ describe('Parse.File testing', () => {
       notEqual(file.name(), 'hello.txt');
     });
 
+    it('saves the file with tags', async () => {
+      spyOn(FilesController.prototype, 'createFile').and.callThrough();
+      const file = new Parse.File('hello.txt', data, 'text/plain');
+      const tags = { hello: 'world' };
+      file.setTags(tags);
+      expect(file.url()).toBeUndefined();
+      const result = await file.save();
+      expect(file.name()).toBeDefined();
+      expect(file.url()).toBeDefined();
+      expect(result.tags()).toEqual(tags);
+      expect(FilesController.prototype.createFile.calls.argsFor(0)[4]).toEqual({
+        tags: tags,
+        metadata: {},
+      });
+    });
+
+    it('does not pass empty file tags while saving', async () => {
+      spyOn(FilesController.prototype, 'createFile').and.callThrough();
+      const file = new Parse.File('hello.txt', data, 'text/plain');
+      expect(file.url()).toBeUndefined();
+      expect(file.name()).toBeDefined();
+      await file.save();
+      expect(file.url()).toBeDefined();
+      expect(FilesController.prototype.createFile.calls.argsFor(0)[4]).toEqual({
+        metadata: {},
+      });
+    });
+
     it('save file in object', async done => {
       const file = new Parse.File('hello.txt', data, 'text/plain');
       ok(!file.url());