I am using Uri.EncodeDataString to send a query string on a URL. The original string is: Photo($select=Name,Id)
In my asp.net web service running in the VS2015 debugger, Uri.EncodeDataString will return: Photo(%24select%3DName%2CId)
However, in an NUnit test running under the Resharper test runner in VS2015, it returns: Photo%28%24select%3DName%2CId%29. Notice the difference in the encoding of the parentheses.
Why are the parentheses encoded in the unit test but not in the web service? Shouldn't the parentheses be encoded in the web service? I'm running under .Net 4.6, so I shouldn't be affected by the RFC 3986 issue discusssed elsewhere on StackOverflow (here, here, here and a plethora of other places around the net).
In the end, I was indeed affected by the RFC 3986 issue.
It turns out the difference is a "quirks" mode of .Net 4.5. When running in an asp.net application, unless explicitly set, .Net will attempt to maintain application compatibility with previous versions.
I stepped into framework code and found a quirk setting in UriParser. Googling led me to this article about the <httpruntime> element in web.config. Near the end, it says:
"If there is no
<httpRuntime targetFramework>attribute present in Web.config, we assume that the application wanted 4.0 quirks behavior."
Once I added targetFramework="4.5" to my web.config, Uri.EscapeDataString behaved as I expected.