Add RocketChatUserAvatarTest.kt

app/src/test/kotlin/RocketChatUserAvatarTest.kt

+import chat.rocket.android.helper.RocketChatUserAvatar
+import org.junit.Test
+
+class RocketChatUserAvatarTest {
+
+    @Test
+    fun `Test username initials`() {
+        assert(RocketChatUserAvatar.getUsernameInitials("") == "?")
+        assert(RocketChatUserAvatar.getUsernameInitials("?") == "?")
+        assert(RocketChatUserAvatar.getUsernameInitials("f") == "F")
+        assert(RocketChatUserAvatar.getUsernameInitials("B") == "B")
+        assert(RocketChatUserAvatar.getUsernameInitials("fo") == "FO")
+        assert(RocketChatUserAvatar.getUsernameInitials("FO") == "FO")
+        assert(RocketChatUserAvatar.getUsernameInitials("fOo") == "FO")
+        assert(RocketChatUserAvatar.getUsernameInitials("FOO") == "FO")
+        assert(RocketChatUserAvatar.getUsernameInitials("F.O") == "FO")
+        assert(RocketChatUserAvatar.getUsernameInitials("F.o") == "FO")
+        assert(RocketChatUserAvatar.getUsernameInitials("Foo.bar") == "FB")
+        assert(RocketChatUserAvatar.getUsernameInitials("Foobar.bar") == "FB")
+        assert(RocketChatUserAvatar.getUsernameInitials("Foobar.bar.zab") == "FZ")
+    }
+}
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