when you specify files on the command line, you have to specify all of them
Here’s my run:
$ ls
main.go main_test.go
$ go test *.go
ok command-line-arguments 0.003s
note, in my version, I ran with both main.go and main_test.go on the command line
Also, your _test file is not quite right, you need your test function to be called TestXXX and take a pointer to testing.T
Here’s the modified verison:
package main
import (
"testing"
)
func TestFoo(t *testing.T) {
t.Error(foo())
}
and the modified output:
$ go test *.go
--- FAIL: TestFoo (0.00s)
main_test.go:8: Foo
FAIL
FAIL command-line-arguments 0.003s