container: access test case by index in helper

This is more elegant and allows for much easier extension of the tests. Mountinfo is still serialised however due to libPaths nondeterminism.

Signed-off-by: Ophestra <cat@gensokyo.uk>

container/init_test.go

@@ -0,0 +1,43 @@
+package container_test
+
+import (
+	"log"
+	"os"
+	"testing"
+
+	"hakurei.app/command"
+	"hakurei.app/container"
+	"hakurei.app/internal"
+	"hakurei.app/internal/hlog"
+)
+
+const (
+	envDoCheck = "HAKUREI_TEST_DO_CHECK"
+)
+
+var helperCommands []func(c command.Command)
+
+func TestMain(m *testing.M) {
+	container.TryArgv0(hlog.Output{}, hlog.Prepare, internal.InstallOutput)
+
+	if os.Getenv(envDoCheck) == "1" {
+		c := command.New(os.Stderr, log.Printf, "helper", func(args []string) error {
+			log.SetFlags(0)
+			log.SetPrefix("helper: ")
+			return nil
+		})
+		for _, f := range helperCommands {
+			f(c)
+		}
+		c.MustParse(os.Args[1:], func(err error) {
+			if err != nil {
+				log.Fatal(err.Error())
+			}
+		})
+		return
+	}
+
+	os.Exit(m.Run())
+}
+
+func prepareHelper(c *container.Container) { c.Env = append(c.Env, envDoCheck+"=1") }