Add test notification tool (#28334)

* Add test notification tool

* Add frontend styles

* Remove option from admin view

* Refactor create post and add translations

* Fix several CI errors

* Fix API and frontend snapshots

* Refactor trailing and leading icon on buttons

* Add different button states

* i18n-extract

* Fix wrong text

* Add tests

* Fix wrong string

* Fix test

* feat: E2E send test notifications (#28371)

* Refactor send desktop notification

* Address rest of the feedback

* Fix tests

* Add correct link

* Fix test

---------

Co-authored-by: Mattermost Build <build@mattermost.com>
Co-authored-by: yasserfaraazkhan <attitude3cena.yf@gmail.com>

server/channels/app/post_test.go

@@ -1178,6 +1178,37 @@ func TestCreatePost(t *testing.T) {
 
 		wg.Wait()
 	})
+
+	t.Run("should sanitize the force notifications prop if the flag is not set", func(t *testing.T) {
+		th := Setup(t).InitBasic()
+		defer th.TearDown()
+		th.AddUserToChannel(th.BasicUser, th.BasicChannel)
+
+		postToCreate := &model.Post{
+			ChannelId: th.BasicChannel.Id,
+			Message:   "hello world",
+			UserId:    th.BasicUser.Id,
+		}
+		postToCreate.AddProp(model.PostPropsForceNotification, model.NewId())
+		createdPost, err := th.App.CreatePost(th.Context, postToCreate, th.BasicChannel, model.CreatePostFlags{})
+		require.Nil(t, err)
+		require.Empty(t, createdPost.GetProp(model.PostPropsForceNotification))
+	})
+
+	t.Run("should add the force notifications prop if the flag is set", func(t *testing.T) {
+		th := Setup(t).InitBasic()
+		defer th.TearDown()
+		th.AddUserToChannel(th.BasicUser, th.BasicChannel)
+
+		postToCreate := &model.Post{
+			ChannelId: th.BasicChannel.Id,
+			Message:   "hello world",
+			UserId:    th.BasicUser.Id,
+		}
+		createdPost, err := th.App.CreatePost(th.Context, postToCreate, th.BasicChannel, model.CreatePostFlags{ForceNotification: true})
+		require.Nil(t, err)
+		require.NotEmpty(t, createdPost.GetProp(model.PostPropsForceNotification))
+	})
 }
 
 func TestPatchPost(t *testing.T) {
@@ -3739,3 +3770,13 @@ func TestPermanentDeletePost(t *testing.T) {
 		assert.Len(t, infos, 0)
 	})
 }
+
+func TestSendTestMessage(t *testing.T) {
+	th := Setup(t).InitBasic()
+	defer th.TearDown()
+	t.Run("Should create the post with the correct prop", func(t *testing.T) {
+		post, result := th.App.SendTestMessage(th.Context, th.BasicUser.Id)
+		assert.Nil(t, result)
+		assert.NotEmpty(t, post.GetProp(model.PostPropsForceNotification))
+	})
+}