[client] Refactor/iface pkg (#2646)

Refactor the flat code structure

client/iface/freebsd/iface_internal_test.go

@@ -0,0 +1,76 @@
+package freebsd
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestParseIfconfigOutput(t *testing.T) {
+	testOutput := `wg1: flags=8080<NOARP,MULTICAST> metric 0 mtu 1420
+    options=80000<LINKSTATE>
+    groups: wg
+    nd6 options=109<PERFORMNUD,IFDISABLED,NO_DAD>`
+
+	expected := &iface{
+		Name:  "wg1",
+		MTU:   1420,
+		Group: "wg",
+	}
+
+	result, err := parseIfconfigOutput(([]byte)(testOutput))
+	if err != nil {
+		t.Errorf("Error parsing ifconfig output: %v", err)
+		return
+	}
+
+	assert.Equal(t, expected.Name, result.Name, "Name should match")
+	assert.Equal(t, expected.MTU, result.MTU, "MTU should match")
+	assert.Equal(t, expected.Group, result.Group, "Group should match")
+}
+
+func TestParseIFName(t *testing.T) {
+	tests := []struct {
+		name        string
+		output      string
+		expected    string
+		expectedErr error
+	}{
+		{
+			name:     "ValidOutput",
+			output:   "eth0\n",
+			expected: "eth0",
+		},
+		{
+			name:     "ValidOutputOneLine",
+			output:   "eth0",
+			expected: "eth0",
+		},
+		{
+			name:        "EmptyOutput",
+			output:      "",
+			expectedErr: fmt.Errorf("no output returned"),
+		},
+		{
+			name:        "InvalidOutput",
+			output:      "This is an invalid output\n",
+			expectedErr: fmt.Errorf("invalid output"),
+		},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			result, err := parseIFName(([]byte)(test.output))
+
+			assert.Equal(t, test.expected, result, "Interface names should match")
+
+			if test.expectedErr != nil {
+				assert.NotNil(t, err, "Error should not be nil")
+				assert.EqualError(t, err, test.expectedErr.Error(), "Error messages should match")
+			} else {
+				assert.Nil(t, err, "Error should be nil")
+			}
+		})
+	}
+}