Adding ErrorAssertionFunc function type

[ccarstens]

Hi @shoenig, thank you for creating this formidable assertion lib! :)

The type I added is analog to testify's ErrorAssertionFunc type that makes it convenient to pass Error or NoError assertion functions in table driven tests.
Do you like the idea of adding this type?
I wasn't sure what the best placement of the type in the source file would be, so please let me know if you wanna move it somewhere else.
Best,
Cornelius

[shoenig]

Hi @ccarstens! I can see why this would be useful and would be glad to add it. I would just want to see two things - a doc string explaining what the type is useful for, and once that's in place, run make generate to make sure it gets copied to the generated must package. Thanks!

[ccarstens]

Hi @shoenig! Ok that sounds great! I added a godoc comment and I ran make generate.
I'm on macOS and the sed commands don't work out of the box like this.
Are you interested in the addition of a separate make generate-macos function? If so, I'm happy to add it with sed commands that work on macOS.

[shoenig]

Thanks @ccarstens! I created #156 with some thoughts about fixing the BSD sed problem. The script could definitely be refactored, since it's just applying the same 3 operations to a list of those 11 files. But just making it so sed does the right thing depending on the version is also an option. In any case we have that separate issue now ~