ci: 👷 Change CI to add test files

Tests/Stream/StreamTest.cs

@@ -2,5 +2,12 @@ namespace Tests.Stream;
 
 public class StreamTest
 {
-    
+    [Theory]
+    [InlineData("thisfileexist.txt", true)]
+    [InlineData("thisfiledontexist.txt", false)]
+
+    public void ExistFileTest(string filePath, bool expected)
+    {
+        Assert.Equal(expected, global::Stream.Stream.ExistFile(filePath));
+    }
 }