A few things have come up recently that could be solved by giving tests a bit more
control over func main.
Suppose we define a type testing.Main analogous to testing.T or testing.PB - it's there
just to have methods to call - with one method Run() (exitcode int). Then the default
test main.main would refactor to:
func main() {
// various registration
// create m
os.Exit(m.Run())
}
But if a test package contains a func TestMain(m *testing.Main), then the main.main
becomes:
func main() {
// various registration
// create m
pkg.TestMain(m.Run())
}
The minimal TestMain is
func TestMain(m *testing.Main) { os.Exit(m.Run()) }
but giving people the ability to write this solves a few problems that have been asked
for.
issue #7905: need to run graphics on main thread
func TestMain(m *testing.Main) {
go func() {
os.Exit(m.Run())
}()
runGraphics()
}
issue #8159: testing setup/shutdown hook:
func TestMain(m *testing.Main) {
setup()
exitCode := m.Run()
shutdown()
os.Exit(exitCode)
}
