# ConditionalIgnore attribute This attribute is an alternative to the standard `Ignore` attribute in [NUnit](http://www.nunit.org/). It allows for ignoring tests only under a specified condition. The condition evaluates during `OnLoad`, referenced by ID. ## Example The following example shows a method to use the `ConditionalIgnore` attribute to ignore a test if the Unity Editor is running macOS: ```C# using UnityEditor; using NUnit.Framework; using UnityEngine.TestTools; [InitializeOnLoad] public class OnLoad { static OnLoad() { var editorIsOSX = false; #if UNITY_EDITOR_OSX editorIsOSX = true; #endif ConditionalIgnoreAttribute.AddConditionalIgnoreMapping("IgnoreInMacEditor", editorIsOSX); } } public class MyTestClass { [Test, ConditionalIgnore("IgnoreInMacEditor", "Ignored on Mac editor.")] public void TestNeverRunningInMacEditor() { Assert.Pass(); } } ``` > **Note**: You can only use `InitializeOnLoad` in **Edit Mode** tests.