From 7f2cd7be24eed211d940d94551daf32eb4c26cb4 Mon Sep 17 00:00:00 2001
From: DevMhrn <debashismaharana7854@gmail.com>
Date: Thu, 4 Jun 2026 02:47:07 +0530
Subject: [PATCH] refactor(unikernels): drop redundant monitor check in Linux
 block cli, add tests

Signed-off-by: DevMhrn <debashismaharana7854@gmail.com>
---
 pkg/unikontainers/unikernels/linux.go      |  6 +-
 pkg/unikontainers/unikernels/linux_test.go | 80 ++++++++++++++++++++++
 2 files changed, 81 insertions(+), 5 deletions(-)
 create mode 100644 pkg/unikontainers/unikernels/linux_test.go

diff --git a/pkg/unikontainers/unikernels/linux.go b/pkg/unikontainers/unikernels/linux.go
index d6bb80952..3ccea8ade 100644
--- a/pkg/unikontainers/unikernels/linux.go
+++ b/pkg/unikontainers/unikernels/linux.go
@@ -170,12 +170,8 @@ func (l *Linux) MonitorBlockCli() []types.MonitorBlockArgs {
 		}
 	case "firecracker":
 		for _, aBlock := range l.Blk {
-			id := aBlock.ID
-			if l.Monitor == "firecracker" {
-				id = "FC" + aBlock.ID
-			}
 			blkArgs = append(blkArgs, types.MonitorBlockArgs{
-				ID:   id,
+				ID:   "FC" + aBlock.ID,
 				Path: aBlock.Source,
 			})
 		}
diff --git a/pkg/unikontainers/unikernels/linux_test.go b/pkg/unikontainers/unikernels/linux_test.go
new file mode 100644
index 000000000..95f7da19a
--- /dev/null
+++ b/pkg/unikontainers/unikernels/linux_test.go
@@ -0,0 +1,80 @@
+// Copyright (c) 2023-2026, Nubificus LTD
+//
+// 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.
+
+package unikernels
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+
+	"github.com/urunc-dev/urunc/pkg/unikontainers/types"
+)
+
+func TestLinuxMonitorBlockCli(t *testing.T) {
+	t.Parallel()
+
+	blocks := []types.BlockDevParams{
+		{ID: "rootfs", Source: "/host/rootfs.img"},
+		{ID: "vol0", Source: "/host/vol0.img"},
+	}
+
+	tests := []struct {
+		name    string
+		monitor string
+		blk     []types.BlockDevParams
+		want    []types.MonitorBlockArgs
+	}{
+		{
+			name:    "no blocks returns nil",
+			monitor: "qemu",
+			blk:     nil,
+			want:    nil,
+		},
+		{
+			name:    "qemu emits ExactArgs without FC prefix",
+			monitor: "qemu",
+			blk:     blocks,
+			want: []types.MonitorBlockArgs{
+				{ExactArgs: " -device virtio-blk-pci,serial=rootfs,drive=rootfs" +
+					" -drive format=raw,if=none,id=rootfs,file=/host/rootfs.img"},
+				{ExactArgs: " -device virtio-blk-pci,serial=vol0,drive=vol0" +
+					" -drive format=raw,if=none,id=vol0,file=/host/vol0.img"},
+			},
+		},
+		{
+			name:    "firecracker prefixes every ID with FC",
+			monitor: "firecracker",
+			blk:     blocks,
+			want: []types.MonitorBlockArgs{
+				{ID: "FCrootfs", Path: "/host/rootfs.img"},
+				{ID: "FCvol0", Path: "/host/vol0.img"},
+			},
+		},
+		{
+			name:    "unknown monitor returns nil",
+			monitor: "hvt",
+			blk:     blocks,
+			want:    nil,
+		},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			t.Parallel()
+			l := &Linux{Monitor: tc.monitor, Blk: tc.blk}
+			assert.Equal(t, tc.want, l.MonitorBlockCli())
+		})
+	}
+}