Adding team_name to post props for channel mentions (#14150)

* Adding team_name to post props for channel mentions

* Fixing tests

Co-authored-by: mattermod <mattermod@users.noreply.github.com>

app/post.go

@@ -375,8 +375,13 @@ func (a *App) FillInPostProps(post *model.Post, channel *model.Channel) *model.A
 
 		for _, mentioned := range mentionedChannels {
 			if mentioned.Type == model.CHANNEL_OPEN {
+				team, err := a.Srv().Store.Team().Get(mentioned.TeamId)
+				if err != nil {
+					mlog.Error("Failed to get team of the channel mention", mlog.String("team_id", channel.TeamId), mlog.String("channel_id", channel.Id), mlog.Err(err))
+				}
 				channelMentionsProp[mentioned.Name] = map[string]interface{}{
 					"display_name": mentioned.DisplayName,
+					"team_name":    team.Name,
 				}
 			}
 		}

app/post_test.go

@@ -432,6 +432,7 @@ func TestPostChannelMentions(t *testing.T) {
 	assert.Equal(t, map[string]interface{}{
 		"mention-test": map[string]interface{}{
 			"display_name": "Mention Test",
+			"team_name":    th.BasicTeam.Name,
 		},
 	}, result.GetProp("channel_mentions"))
 
@@ -441,6 +442,7 @@ func TestPostChannelMentions(t *testing.T) {
 	assert.Equal(t, map[string]interface{}{
 		"mention-test": map[string]interface{}{
 			"display_name": "Mention Test",
+			"team_name":    th.BasicTeam.Name,
 		},
 	}, result.GetProp("channel_mentions"))
 }