diff --git a/cmd/uncloud/internal/logs/logs_test.go b/cmd/uncloud/internal/logs/logs_test.go
new file mode 100644
index 00000000..f82845f4
--- /dev/null
+++ b/cmd/uncloud/internal/logs/logs_test.go
@@ -0,0 +1,108 @@
+package logs
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestParseServiceArgs(t *testing.T) {
+	t.Parallel()
+
+	tests := []struct {
+		name    string
+		args    []string
+		want    []ServiceArg
+		wantErr string
+	}{
+		{
+			name: "empty input",
+			args: nil,
+			want: []ServiceArg{},
+		},
+		{
+			name: "single bareword service",
+			args: []string{"web"},
+			want: []ServiceArg{{Service: "web"}},
+		},
+		{
+			name: "single container",
+			args: []string{"web/abc123"},
+			want: []ServiceArg{{Service: "web", Containers: []string{"abc123"}}},
+		},
+		{
+			name: "multiple containers same service",
+			args: []string{"web/abc123", "web/def456"},
+			want: []ServiceArg{{Service: "web", Containers: []string{"abc123", "def456"}}},
+		},
+		{
+			name: "multiple services interleaved",
+			args: []string{"web/abc123", "api", " web/def456  ", "db/xyz789 "},
+			want: []ServiceArg{
+				{Service: "web", Containers: []string{"abc123", "def456"}},
+				{Service: "api"},
+				{Service: "db", Containers: []string{"xyz789"}},
+			},
+		},
+		{
+			name: "bareword wins when seen first",
+			args: []string{"web", "web/abc123"},
+			want: []ServiceArg{{Service: "web"}},
+		},
+		{
+			name: "bareword wins when seen later",
+			args: []string{"web/abc123", "web/def456", "web"},
+			want: []ServiceArg{{Service: "web"}},
+		},
+		{
+			name: "bareword wins followed by more container args",
+			args: []string{"web/abc123", "web", "web/def456"},
+			want: []ServiceArg{{Service: "web"}},
+		},
+		{
+			name: "preserves first-seen service order",
+			args: []string{"db", "api", "web"},
+			want: []ServiceArg{
+				{Service: "db"},
+				{Service: "api"},
+				{Service: "web"},
+			},
+		},
+		{
+			name:    "empty arg",
+			args:    []string{""},
+			wantErr: "empty service argument",
+		},
+		{
+			name:    "empty spaces arg",
+			args:    []string{"   "},
+			wantErr: "empty service argument",
+		},
+		{
+			name:    "missing service half",
+			args:    []string{"/abc123"},
+			wantErr: "service name is empty",
+		},
+		{
+			name:    "missing container half",
+			args:    []string{"web/"},
+			wantErr: "container name or ID is empty",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+
+			got, err := ParseServiceArgs(tt.args)
+			if tt.wantErr != "" {
+				require.Error(t, err)
+				assert.ErrorContains(t, err, tt.wantErr)
+				return
+			}
+			require.NoError(t, err)
+			assert.Equal(t, tt.want, got)
+		})
+	}
+}