ExitIfSmallMachine emits a helpful diagnostic and calls os.Exit(0) if the current machine is a builder known to have scarce resources.

Go1Point returns the x in Go 1.x.

NeedsGo1Point skips t if the Go version used to run the test is older than 1.x.

NeedsGoBuild skips t if the current system can't build programs with ``go build'' and then run them with os.StartProcess or exec.Command.

NeedsGoPackages skips t if the go/packages driver (or 'go' tool) implied by the current process environment is not present in the path.

NeedsGoPackagesEnv skips t if the go/packages driver (or 'go' tool) implied by env is not present in the path.

NeedsTool skips t if the named tool is not present in the path.

SkipAfterGo1Point skips t if the Go version used to run the test is newer than 1.x.

Testing is an abstraction of a *testing.T.