Add test for cmd/conflictless

cmd/conflictless/main_test.go

@@ -0,0 +1,33 @@
+package main
+
+import (
+	"errors"
+	"os"
+	"os/exec"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func Test_main(t *testing.T) {
+	t.Parallel()
+
+	if os.Getenv("TEST_MAIN_CLI") == "1" {
+		main()
+
+		return
+	}
+
+	//nolint:gosec // this is a test package so G204 doesn't really matter here.
+	cmd := exec.Command(os.Args[0], "-test.run=^Test_main$")
+
+	cmd.Env = append(os.Environ(), "TEST_MAIN_CLI=1")
+	err := cmd.Run()
+
+	assert.IsType(t, new(exec.ExitError), err)
+
+	exitErr := new(*exec.ExitError)
+	errors.As(err, exitErr)
+
+	assert.Equal(t, 2, (*exitErr).ExitCode(), "process ran with err %v, want exit status 2", err)
+}