Add tests for files in topology directory for offline CPUs

Signed-off-by: Kishen V <[email protected]>

pkg/cpu/cpu_linux_test.go

@@ -7,8 +7,11 @@
 package cpu_test
 
 import (
+	"bytes"
+	"io"
 	"os"
 	"path/filepath"
+	"strings"
 	"testing"
 
 	"github.com/jaypipes/ghw/pkg/cpu"
@@ -71,3 +74,44 @@ func TestArmCPU(t *testing.T) {
 		}
 	}
 }
+
+func TestCheckCPUTopologyFilesForOfflineCPU(t *testing.T) {
+	if _, ok := os.LookupEnv("GHW_TESTING_SKIP_CPU"); ok {
+		t.Skip("Skipping CPU tests.")
+	}
+
+	testdataPath, err := testdata.SnapshotsDirectory()
+	if err != nil {
+		t.Fatalf("Expected nil err, but got %v", err)
+	}
+
+	offlineCPUSnapshot := filepath.Join(testdataPath, "linux-amd64-offlineCPUs.tar.gz")
+
+	// Capture stderr
+	rErr, wErr, err := os.Pipe()
+	if err != nil {
+		t.Fatalf("Cannot pipe StdErr. %v", err)
+	}
+	os.Stderr = wErr
+
+	info, err := cpu.New(option.WithSnapshot(option.SnapshotOptions{
+		Path: offlineCPUSnapshot,
+	}))
+	if err != nil {
+		t.Fatalf("Expected nil err, but got %v", err)
+	}
+	if info == nil {
+		t.Fatalf("Expected non-nil CPUInfo, but got nil")
+	}
+
+	if len(info.Processors) == 0 {
+		t.Fatalf("Expected >0 processors but got 0.")
+	}
+	wErr.Close()
+	var bufErr bytes.Buffer
+	io.Copy(&bufErr, rErr)
+	errorOutput := bufErr.String()
+	if strings.Contains(errorOutput, "WARNING: failed to read int from file:") {
+		t.Fatalf("Unexpected warning related to missing files under topology directory was reported")
+	}
+}