Fix NavigationService tests

Author: jcansdale

test/UnitTests/GitHub.App/Services/NavigationServiceTests.cs

@@ -29,9 +29,10 @@ public void FindNearestMatchingLine(IList<string> fromLines, IList<string> toLin
 
     public class TheFindMatchingLineMethod
     {
-        [TestCase(new[] { "void method()", "code" }, new[] { "void method()", "// code" }, 1, 1)]
+        [TestCase(new[] { "void method()", "code" }, new[] { "void method()", "// code" }, 1, 1, Description = "Find using line below")]
+        [TestCase(new[] { "void method()", "code" }, new[] { "void method()", "// code", "// code" }, 2, -1, Description = "Out of range")]
+        [TestCase(new[] { "code" }, new[] { "// code" }, 0, -1, Description = "No matching line")]
         [TestCase(new[] { "void method()", "code" }, new[] { "void method()" }, 1, 0, Description = "Keep within bounds")]
-        [TestCase(new[] { "code" }, new[] { "// code" }, 0, -1)]
         [TestCase(new[] { "line", "line" }, new[] { "line", "line" }, 0, 0, Description = "Match nearest line")]
         [TestCase(new[] { "line", "line" }, new[] { "line", "line" }, 1, 1, Description = "Match nearest line")]
         public void FindNearestMatchingLine(IList<string> fromLines, IList<string> toLines, int line,
@@ -45,9 +46,5 @@ public void FindNearestMatchingLine(IList<string> fromLines, IList<string> toLin
         }
     }
 
-    static NavigationService CreateNavigationService()
-    {
-        var sp = Substitute.For<IGitHubServiceProvider>();
-        return new NavigationService(sp);
-    }
+    static NavigationService CreateNavigationService() => new NavigationService();
 }