Description
To have code be compiled only during tests, it's easy: just put the code in a file suffixed _test.go. However, there is no mechanism for the complement: to have code that is excluded when testing. I propose we set the tag "test" when the build is being run under "go test".
The desire for this came up for me recently when I wanted to test some code's behavior given a value I wanted to be constant. The only way to do this now is to make it a variable that the test modifies, but a variable is not a constant. There are things you can do with a constant, such as declare array types, that are illegal with a variable.
It was necessary to change the semantics of the code to make it testable. That bothers me.
This is a small problem, I admit, but the proposed solution is also small.