I just updated my old project to use version 4.13.0 and there was a lot of exception validation with ComparisonMode.Substring, but ComparisonMode.Substring does not exist in the newest version. I found this that explains that:
As a result of this, I decided that as of version 2.1, the ComparisonMode is obsolete and any assertions against the exception message is treated as a case-insensitive wildcard match.
But now I get loads of failed tests with:
Expected exception message to match the equivalent of "Value of argument 'PeriodEnd' must be greater than '01.01.0001'", but "Value of argument 'PeriodEnd' must be greater than '01.01.0001'. Value is '01.01.0001'.
Parameter name: PeriodEnd" does not.
string I assert with
Value of argument 'PeriodEnd' must be greater than '01.01.0001'
The one it expects
Value of argument 'PeriodEnd' must be greater than '01.01.0001'. Value is '01.01.0001'.
Parameter name: PeriodEnd
But from the "patch notes" from before it seems that it should be a wildcard, and the string I assert from is a substring of the one it really is, so why does it fail?
You still need to add the wildcard characters to the call to WithMessage, just like you did when ComparisonMode.Wildcard still existed. The rationale is explained in this post:
If you need to verify that a certain string value or exception message matches the expectation, never verify the exact message. Use wildcards to verify the specific parts that are relevant to verify that the behavior meets the expectation. It will save from unexpectingly failing tests if you decide to refine the text involved.