[USDU-249] Adds test case for InitUSD

package/com.unity.formats.usd/Tests/Editor/InitUsdTests.cs

@@ -0,0 +1,74 @@
+using System.IO;
+using NUnit.Framework;
+using System.Reflection;
+using Unity.Formats.USD;
+
+public class InitUsdTests
+{
+    [Test]
+    [Ignore("[USDU-249]")]
+    public void SetupUsdPath_InvalidPath_Error()
+    {
+        // SetupUsdPath function is a private function
+        var setUpMethod = GetMethod("SetupUsdPath");
+
+        try
+        {
+            setUpMethod.Invoke(null, new object[] { "\\NonExisting\\Path\\" });
+        }
+        catch (TargetInvocationException e)
+        {
+            Assert.AreEqual(e.InnerException.GetType(), typeof(FileNotFoundException));
+            return;
+        }
+
+        Assert.Fail("Exception was expected but none was thrown");
+    }
+
+    [Test]
+    public void SetupUsdPath_EmptyPath_Error()
+    {
+        // SetupUsdPath function is a private function
+        var setUpMethod = GetMethod("SetupUsdPath");
+
+        try
+        {
+            setUpMethod.Invoke(null, new object[] { "" });
+        }
+        catch (TargetInvocationException e)
+        {
+            Assert.AreEqual(e.InnerException.GetType(), typeof(System.ArgumentException));
+            return;
+        }
+
+        Assert.Fail("Exception was expected but none was thrown");
+    }
+
+    [Test]
+    public void InitUsd_Initialize()
+    {
+        // Reset 'm_usdInitialized' for accurate testing
+        ResetInitUsd();
+
+        Assert.True(InitUsd.Initialize());
+    }
+
+    [TearDown]
+    public void ResetInitUsd()
+    {
+        var isUsdInitialized = typeof(InitUsd).GetField("m_usdInitialized", (BindingFlags.Static | BindingFlags.NonPublic));
+        isUsdInitialized.SetValue(null, false);
+    }
+
+    private MethodInfo GetMethod(string methodName)
+    {
+        var method = typeof(InitUsd).GetMethod(methodName, (BindingFlags.NonPublic | BindingFlags.Static));
+
+        if (method == null)
+        {
+            Assert.Fail(string.Format("{0} method not found", methodName));
+        }
+
+        return method;
+    }
+}