System.Net.Mail.Tests.MessageEncodeHeadersTest.EncodeHeaders_WithHeadersEncodingPropertySet_ShouldEncodeWithProperEncoding C# (CSharp) Method

        public void EncodeHeaders_WithHeadersEncodingPropertySet_ShouldEncodeWithProperEncoding()
        {
            //note:  this is the WRONG code page to use for the unicode value supplied:  we are not testing that
            //here, we care about whether or not it is using the correct encoding value to encode as specified
            //in the HeadersEncoding property.
            Encoding encoding = Encoding.GetEncoding("utf-32");
            _message.HeadersEncoding = encoding;
            _headers.Add("X-Custom", CustomUnicodeHeaderValue);
            _message.EncodeHeaders(_headers, false);

            string encodedHeader = _headers.Get("X-Custom");
            Assert.True(encodedHeader.StartsWith("="), "didn't start with =");
            Assert.True(encodedHeader.EndsWith("="), "didn't end with =");
            string[] splits = encodedHeader.Split(new char[] { '?' }, StringSplitOptions.RemoveEmptyEntries);
            Assert.Equal("utf-32", splits[1]);
            Assert.Equal(encoding, _message.HeadersEncoding);

            // Allow Unicode, ignore header encoding
            _headers.Clear();
            _headers.Add("X-Custom", CustomUnicodeHeaderValue);
            _message.EncodeHeaders(_headers, true);

            encodedHeader = _headers.Get("X-Custom");
            Assert.False(encodedHeader.StartsWith("="));
            Assert.False(encodedHeader.EndsWith("="));
            Assert.True(ContainsNonAscii(encodedHeader), encodedHeader);
        }