bootloader: Add test for isKernelUncompressed

This ensures both puipui kernel and fedora/RHEL kernels are detected as
uncompressed when they are.

pkg/vf/bootloader_test.go

@@ -0,0 +1,53 @@
+package vf
+
+import (
+	"path/filepath"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+type isUncompressedCheckFunc func(t require.TestingT, value bool, msgAndArgs ...interface{})
+
+type uncompressedKernelTest struct {
+	filename            string
+	isUncompressedCheck isUncompressedCheckFunc
+}
+
+var uncompressedKernelTests = map[string]uncompressedKernelTest{
+	"fedora-amd64-compressed": {
+		filename:            filepath.Join("testdata", "vmlinuz-truncated-6.4.11-200.fc38.x86_64"),
+		isUncompressedCheck: require.False,
+	},
+	"fedora-arm64-compressed": {
+		// this kernel is wrapped in an EFI binary, I don't know how to produce an uncompressed version
+		filename:            filepath.Join("testdata", "vmlinuz-truncated-6.4.11-200.fc38.aarch64"),
+		isUncompressedCheck: require.False,
+	},
+	"puipui-arm64-uncompressed": {
+		filename:            filepath.Join("testdata", "vmlinux-truncated-0.1.0.puipui.aarch64"),
+		isUncompressedCheck: require.True,
+	},
+	"puipui-am64-compressed": {
+		filename:            filepath.Join("testdata", "vmlinux-truncated-0.1.0.puipui.x86_64"),
+		isUncompressedCheck: require.False,
+	},
+	"rhel-arm64-uncompressed": {
+		filename:            filepath.Join("testdata", "vmlinux-truncated-5.14.0-70.72.1.el9_0.aarch64"),
+		isUncompressedCheck: require.True,
+	},
+	"rhel-arm64-compressed": {
+		filename:            filepath.Join("testdata", "vmlinuz-truncated-5.14.0-70.72.1.el9_0.aarch64"),
+		isUncompressedCheck: require.False,
+	},
+}
+
+func TestUncompressedKernel(t *testing.T) {
+	for name, test := range uncompressedKernelTests {
+		t.Run(name, func(t *testing.T) {
+			uncompressed, err := isKernelUncompressed(test.filename)
+			require.NoError(t, err)
+			test.isUncompressedCheck(t, uncompressed)
+		})
+	}
+}