More unit tests, fixes

Plugins/PkmnLib.Plugin.Gen7/Scripts/Side/EchoedVoiceData.cs

@@ -4,11 +4,22 @@ namespace PkmnLib.Plugin.Gen7.Scripts.Side;
 /// Just here to indicate that a Pokemon on this side has used Echoed Voice.
 /// </summary>
 [Script(ScriptCategory.Side, "echoed_voice_data")]
-public class EchoedVoiceData : Script, IScriptOnEndTurn
+public class EchoedVoiceData : Script, IScriptOnBeforeMoveChoice, IScriptStack
 {
-    /// <inheritdoc />
-    public void OnEndTurn(IScriptSource owner, IBattle battle)
+    private int _stacks = 1;
+
+    public int Stacks => _stacks;
+
+    public void OnBeforeMoveChoice(IMoveChoice moveChoice)
     {
-        RemoveSelf();
+        if (moveChoice.ChosenMove.MoveData.Name != "echoed_voice")
+        {
+            RemoveSelf();
+        }
+    }
+
+    public void Stack()
+    {
+        _stacks++;
     }
 }