test: add tests for custom images

tests/check_custom_images.bats

@@ -0,0 +1,52 @@
+#!/usr/bin/env bats
+
+VMPREFIX=batstestvm
+TESTDIR=~/virt/.tests
+
+setup() {
+    # Create test images for custom image tests
+    mkdir -p ~/virt/.tests/
+    qemu-img create -f qcow2 "${TESTDIR}"/test-image.qcow2 1M
+    qemu-img create -f raw "${TESTDIR}"/test-image.raw 1M
+    qemu-img create -f vpc "${TESTDIR}"/test-image.vhd 1M
+}
+
+teardown() {
+    # Clean up test images
+    rm -f "${TESTDIR}"/test-image.*
+    rm -f relative-test.qcow2
+
+    # Clean up any partially created VMs
+    ./kvm-install-vm remove "${VMPREFIX}"-custom-qcow2 2>/dev/null || true
+    ./kvm-install-vm remove "${VMPREFIX}"-custom-raw 2>/dev/null || true
+    ./kvm-install-vm remove "${VMPREFIX}"-custom-vhd 2>/dev/null || true
+    ./kvm-install-vm remove "${VMPREFIX}"-relative 2>/dev/null || true
+}
+
+@test "Custom qcow2 image format detection" {
+    run timeout 1 ./kvm-install-vm create -n -i "${TESTDIR}"/test-image.qcow2 "${VMPREFIX}"-custom-qcow2
+    [[ "${output}" =~ "format: qcow2" ]]
+}
+
+@test "Custom raw image format detection" {
+    run timeout 1 ./kvm-install-vm create -n -i "${TESTDIR}"/test-image.raw "${VMPREFIX}"-custom-raw
+    [[ "${output}" =~ "format: raw" ]]
+}
+
+@test "Custom vhd image format detection" {
+    run timeout 1 ./kvm-install-vm create -n -i "${TESTDIR}"/test-image.vhd "${VMPREFIX}"-custom-vhd
+    [[ "${output}" =~ "format: vpc" ]]
+}
+
+@test "Relative path support with custom image" {
+    cp "${TESTDIR}"/test-image.qcow2 ./relative-test.qcow2
+
+    run timeout 1 ./kvm-install-vm create -n -i ./relative-test.qcow2 "${VMPREFIX}"-relative.qcow2
+    [[ "${output}" =~ "format: qcow2" ]]
+    [[ "${output}" =~ "/relative-test.qcow2" ]]
+}
+
+@test "Nonexistent custom image fails gracefully" {
+    run ./kvm-install-vm create -i /nonexistent/image.qcow2 "${VMPREFIX}"-nonexistent
+    [ "$status" -ne 0 ]
+}