Requirements

Any test.Case has a Require property that allow enforcing specific, per-test requirements.

A Requirement is expected to make you Skip tests when the environment does not match expectations.

A number of ready-made requirements are provided:

require.Windows // a test runs only on Windows
require.Linux // a test runs only on Linux
test.Darwin // a test runs only on Darwin
test.OS(name string) // a test runs only on the OS `name`
require.Binary(name string) // a test requires the binary `name` to be in the PATH
require.Not(req Requirement) // a test runs only if the opposite of the requirement `req` is fulfilled
require.All(req ...Requirement) // a test runs only if all requirements are fulfilled

Custom requirements

A requirement is a simple struct (test.Requirement), that must provide a Check function.

Check function signature is func(data Data, helpers Helpers) (bool, string), that is expected to return true if the environment is fine to run that test, or false if not. The second parameter should return a meaningful message explaining what the requirement is.

For example: found kernel version > 5.0.

Given requirements can be negated with require.Not(req), your message should describe the state of the environment and not whether the conditions are met (or not met).

A test.Requirement can optionally provide custom Setup and Cleanup routines, in case you need to perform specific operations before the test run (and cleanup something after).

Setup/Cleanup will only run if the requirement Check returns true.

Here is for example how the require.Binary method is implemented:

package thing

func Binary(name string) *test.Requirement {
    return &test.Requirement{
        Check: func(_ test.Data, _ test.Helpers) (bool, string) {
            mess := fmt.Sprintf("executable %q has been found in PATH", name)
            ret := true
            if _, err := exec.LookPath(name); err != nil {
                ret = false
                mess = fmt.Sprintf("executable %q doesn't exist in PATH", name)
            }

            return ret, mess
        },
    }
}

Gotcha

Obviously, test.Not(otherreq) will NOT perform any Setup/Cleanup provided by otherreq.

Ambient requirements are currently undocumented.