ScriptTest.cs

using NUnit.Framework;
using System.Collections;
using UnityEngine.TestTools;

public class NewEditModeTest {

	// A UnityTest behaves like a coroutine in PlayMode
	// and allows you to yield null to skip a frame in EditMode
	[UnityTest]
	public IEnumerator NewEditModeTestWithEnumeratorPasses() {
        // Use the Assert class to test conditions.
        // yield to skip a frame
        var tts = new TextToSpeech();

        var resp = tts.RequestToken();
        yield return resp;

        Assert.AreEqual(true,true);
    }
}