refactor: modularize audit and harden build validation

audit/internal/platform/tpm_test.go

@@ -1,11 +1,66 @@
 package platform
 
 import (
+	"os"
+	"path/filepath"
 	"reflect"
 	"strings"
 	"testing"
 )
 
+func TestRunTPMValidationPackSkipsWhenNoTPMDevice(t *testing.T) {
+	old := tpmDeviceGlob
+	tpmDeviceGlob = func() []string { return nil }
+	t.Cleanup(func() { tpmDeviceGlob = old })
+
+	dir := t.TempDir()
+	runDir, err := (&System{}).RunTPMValidationPack(nil, dir, nil)
+	if err != nil {
+		t.Fatalf("RunTPMValidationPack: %v", err)
+	}
+	for _, name := range []string{"01-properties-fixed.log", "02-pcr-banks.log", "03-pcr-values.log", "04-test-result.log"} {
+		if _, err := os.Stat(filepath.Join(runDir, name)); err == nil {
+			t.Fatalf("tpm2 job %q ran despite no TPM device", name)
+		}
+	}
+	summary, err := os.ReadFile(filepath.Join(runDir, "summary.txt"))
+	if err != nil {
+		t.Fatalf("read summary: %v", err)
+	}
+	if !strings.Contains(string(summary), "overall_status=UNSUPPORTED") ||
+		!strings.Contains(string(summary), "tpm_present=false") {
+		t.Fatalf("summary missing UNSUPPORTED/tpm_present markers:\n%s", summary)
+	}
+}
+
+func TestTPMPresentRequiresVersion2(t *testing.T) {
+	oldGlob, oldRead := tpmDeviceGlob, tpmReadFile
+	t.Cleanup(func() {
+		tpmDeviceGlob = oldGlob
+		tpmReadFile = oldRead
+	})
+
+	tests := []struct {
+		name    string
+		version string
+		readErr error
+		want    bool
+	}{
+		{name: "TPM 2", version: "2\n", want: true},
+		{name: "TPM 1.2", version: "1\n", want: false},
+		{name: "missing version attribute", readErr: os.ErrNotExist, want: false},
+	}
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			tpmDeviceGlob = func() []string { return []string{"/sys/class/tpm/tpm0"} }
+			tpmReadFile = func(string) ([]byte, error) { return []byte(test.version), test.readErr }
+			if got := (&System{}).TPMPresent(); got != test.want {
+				t.Fatalf("TPMPresent()=%v want %v", got, test.want)
+			}
+		})
+	}
+}
+
 func TestTPMValidationJobsAreReadOnly(t *testing.T) {
 	t.Parallel()