test(unikontainers): add unit tests for pure functions

pkg/unikontainers/ipc_message_test.go

@@ -0,0 +1,105 @@
+// 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 unikontainers
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/vishvananda/netlink/nl"
+	"golang.org/x/sys/unix"
+)
+
+func TestInt32msgSerialize(t *testing.T) {
+	native := nl.NativeEndian()
+	tests := []struct {
+		name    string
+		msgType uint16
+		value   uint32
+	}{
+		{
+			name:    "clone flags attribute with typical value",
+			msgType: cloneFlagsAttr,
+			value:   unix.CLONE_NEWNET | unix.CLONE_NEWPID,
+		},
+		{
+			name:    "zero value",
+			msgType: cloneFlagsAttr,
+			value:   0,
+		},
+		{
+			name:    "max uint32 value",
+			msgType: oomScoreAdjAttr,
+			value:   ^uint32(0),
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+			msg := &int32msg{Type: tt.msgType, Value: tt.value}
+			got := msg.Serialize()
+			assert.Equal(t, 8, len(got))
+			assert.Equal(t, uint16(8), native.Uint16(got[0:2]))
+			assert.Equal(t, tt.msgType, native.Uint16(got[2:4]))
+			assert.Equal(t, tt.value, native.Uint32(got[4:8]))
+		})
+	}
+}
+
+func TestBytemsgSerialize(t *testing.T) {
+	native := nl.NativeEndian()
+	tests := []struct {
+		name      string
+		msgType   uint16
+		value     []byte
+		wantPanic bool
+	}{
+		{
+			name:    "empty value produces aligned buffer",
+			msgType: nsPathsAttr,
+			value:   []byte{},
+		},
+		{
+			name:    "non-empty value encodes correctly",
+			msgType: nsPathsAttr,
+			value:   []byte("net:/tmp/netns"),
+		},
+		{
+			name:      "oversized value panics with netlinkError",
+			msgType:   nsPathsAttr,
+			value:     make([]byte, 65532),
+			wantPanic: true,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+			msg := &bytemsg{Type: tt.msgType, Value: tt.value}
+			if tt.wantPanic {
+				assert.Panics(t, func() { msg.Serialize() })
+				return
+			}
+			got := msg.Serialize()
+			l := msg.Len()
+			expectedLen := (l + unix.NLA_ALIGNTO - 1) &^ (unix.NLA_ALIGNTO - 1)
+			assert.Equal(t, expectedLen, len(got))
+			assert.Equal(t, uint16(l), native.Uint16(got[0:2])) //nolint: gosec
+			assert.Equal(t, tt.msgType, native.Uint16(got[2:4]))
+			if len(tt.value) > 0 {
+				assert.Equal(t, tt.value, got[unix.NLA_HDRLEN:unix.NLA_HDRLEN+len(tt.value)])
+			}
+		})
+	}
+}

pkg/unikontainers/mount_test.go

@@ -0,0 +1,54 @@
+// 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 unikontainers
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"golang.org/x/sys/unix"
+)
+
+func TestMapRootfsPropagationFlag(t *testing.T) {
+	tests := []struct {
+		name     string
+		input    string
+		expected int
+		wantErr  bool
+	}{
+		{name: "rprivate", input: "rprivate", expected: unix.MS_PRIVATE | unix.MS_REC},
+		{name: "private", input: "private", expected: unix.MS_PRIVATE},
+		{name: "rslave", input: "rslave", expected: unix.MS_SLAVE | unix.MS_REC},
+		{name: "slave", input: "slave", expected: unix.MS_SLAVE},
+		{name: "rshared", input: "rshared", expected: unix.MS_SHARED | unix.MS_REC},
+		{name: "shared", input: "shared", expected: unix.MS_SHARED},
+		{name: "runbindable", input: "runbindable", expected: unix.MS_UNBINDABLE | unix.MS_REC},
+		{name: "unbindable", input: "unbindable", expected: unix.MS_UNBINDABLE},
+		{name: "unknown value returns error", input: "unknown", wantErr: true},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+			got, err := mapRootfsPropagationFlag(tt.input)
+			if tt.wantErr {
+				assert.Error(t, err)
+				assert.Equal(t, 0, got)
+				return
+			}
+			assert.NoError(t, err)
+			assert.Equal(t, tt.expected, got)
+		})
+	}
+}

pkg/unikontainers/shared_fs_test.go

@@ -0,0 +1,66 @@
+// 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 unikontainers
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestChooseTmpfsSize(t *testing.T) {
+	const (
+		mem256MB uint64 = 256 * 1024 * 1024
+		mem512MB uint64 = 512 * 1024 * 1024
+	)
+	tests := []struct {
+		name     string
+		sfsType  string
+		mem      uint64
+		expected string
+	}{
+		{
+			name:     "9pfs returns constant regardless of memory",
+			sfsType:  "9pfs",
+			mem:      mem256MB,
+			expected: tmpfsSizeFor9pfsRootfs,
+		},
+		{
+			name:     "virtiofs 256 MB adds 1 MiB overhead",
+			sfsType:  "virtiofs",
+			mem:      mem256MB,
+			expected: "269m",
+		},
+		{
+			name:     "virtiofs 512 MB adds 1 MiB overhead",
+			sfsType:  "virtiofs",
+			mem:      mem512MB,
+			expected: "537m",
+		},
+		{
+			name:     "virtiofs zero memory uses 1 MiB overhead only",
+			sfsType:  "virtiofs",
+			mem:      0,
+			expected: "1m",
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+			got := chooseTmpfsSize(tt.sfsType, tt.mem)
+			assert.Equal(t, tt.expected, got)
+		})
+	}
+}