implement drm card test

sysfs/class_drm_card_port.go

@@ -11,6 +11,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+//go:build !windows
 // +build !windows
 
 package sysfs

sysfs/class_drm_card_test.go

@@ -0,0 +1,51 @@
+// Copyright 2021 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build linux
+// +build linux
+
+package sysfs
+
+import (
+	"reflect"
+	"testing"
+)
+
+func TestClassDRMCard(t *testing.T) {
+	fs, err := NewFS(sysTestFixtures)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	drmCardTest, err := fs.ClassDrmCard()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	classDrmCard := []ClassDrmCard{
+		{
+			Name:   "card0",
+			Enable: 1,
+			Driver: "amdgpu",
+		},
+		{
+			Name:   "card1",
+			Enable: 1,
+			Driver: "i915",
+		},
+	}
+
+	if !reflect.DeepEqual(classDrmCard, drmCardTest) {
+		t.Errorf("Result not correct: want %v, have %v", classDrmCard, drmCardTest)
+	}
+}