System.Tests.StringTests.IndexOf_CyrillicE C# (CSharp) Method

        public static void IndexOf_CyrillicE()
        {
            string s = "Foo\u0400Bar";
            string value = "\u0400";
            Helpers.PerformActionWithCulture(new CultureInfo("en-US"), () =>
            {
                Assert.Equal(3, s.IndexOf(value));
                Assert.Equal(3, s.IndexOf(value, StringComparison.CurrentCulture));
                Assert.Equal(3, s.IndexOf(value, StringComparison.CurrentCultureIgnoreCase));
                Assert.Equal(3, s.IndexOf(value, StringComparison.Ordinal));
                Assert.Equal(3, s.IndexOf(value, StringComparison.OrdinalIgnoreCase));
            });
            Helpers.PerformActionWithCulture(CultureInfo.InvariantCulture, () =>
            {
                Assert.Equal(3, s.IndexOf(value));
                Assert.Equal(3, s.IndexOf(value, StringComparison.CurrentCulture));
                Assert.Equal(3, s.IndexOf(value, StringComparison.CurrentCultureIgnoreCase));
            });

            value = "bar";
            Helpers.PerformActionWithCulture(new CultureInfo("en-US"), () =>
            {
                Assert.Equal(-1, s.IndexOf(value));
                Assert.Equal(-1, s.IndexOf(value, StringComparison.CurrentCulture));
                Assert.Equal(4, s.IndexOf(value, StringComparison.CurrentCultureIgnoreCase));
                Assert.Equal(-1, s.IndexOf(value, StringComparison.Ordinal));
                Assert.Equal(4, s.IndexOf(value, StringComparison.OrdinalIgnoreCase));
            });
            Helpers.PerformActionWithCulture(CultureInfo.InvariantCulture, () =>
            {
                Assert.Equal(-1, s.IndexOf(value));
                Assert.Equal(-1, s.IndexOf(value, StringComparison.CurrentCulture));
                Assert.Equal(4, s.IndexOf(value, StringComparison.CurrentCultureIgnoreCase));
            });
        }