Unify all locations where we determine a user's display named based off of their nickname/username into a helper function

model/user.go

@@ -237,6 +237,14 @@ func (u *User) AddNotifyProp(key string, value string) {
 	u.NotifyProps[key] = value
 }
 
+func (u *User) GetDisplayName() string {
+	if u.Nickname != "" {
+		return u.Nickname
+	} else {
+		return u.Username
+	}
+}
+
 // UserFromJson will decode the input and return a User
 func UserFromJson(data io.Reader) *User {
 	decoder := json.NewDecoder(data)

model/user_test.go

@@ -107,3 +107,16 @@ func TestUserIsValid(t *testing.T) {
 		t.Fatal(err)
 	}
 }
+
+func TestUserGetDisplayName(t *testing.T) {
+	user := User{FirstName: "first", LastName: "last", Username: "user"}
+
+	if displayName := user.GetDisplayName(); displayName != "user" {
+		t.Fatal("Display name should be username")
+	}
+
+	user.Nickname = "nickname"
+	if displayName := user.GetDisplayName(); displayName != "nickname" {
+		t.Fatal("Display name should be nickname")
+	}
+}