test: add unit tests for socket diff functionality

Signed-off-by: Hamza Dogar <hxadogar@gmail.com>

Author: hxadogar

cmd/diff_test.go

@@ -0,0 +1,284 @@
+// SPDX-License-Identifier: Apache-2.0
+
+package cmd
+
+import (
+	"testing"
+)
+
+// compareSockets [empty inputs]
+func TestCompareSocketsEmptyInputs(t *testing.T) {
+	result := compareSockets([]SkNode{}, []SkNode{})
+
+	if result == nil {
+		t.Fatal("Expected non-nil result for empty inputs")
+	}
+
+	if len(result.Added) != 0 {
+		t.Errorf("Expected 0 added sockets, got %d", len(result.Added))
+	}
+
+	if len(result.Removed) != 0 {
+		t.Errorf("Expected 0 removed sockets, got %d", len(result.Removed))
+	}
+
+	if result.Unchanged != 0 {
+		t.Errorf("Expected 0 unchanged sockets, got %d", result.Unchanged)
+	}
+}
+
+func TestCompareSocketsNilInputs(t *testing.T) {
+	result := compareSockets(nil, nil)
+
+	if result == nil {
+		t.Fatal("Expected non-nil result for nil inputs")
+	}
+
+	if len(result.Added) != 0 {
+		t.Errorf("Expected 0 added sockets for nil inputs, got %d", len(result.Added))
+	}
+
+	if len(result.Removed) != 0 {
+		t.Errorf("Expected 0 removed sockets for nil inputs, got %d", len(result.Removed))
+	}
+
+	if result.Unchanged != 0 {
+		t.Errorf("Expected 0 unchanged sockets for nil inputs, got %d", result.Unchanged)
+	}
+}
+
+// added sockets
+func TestCompareSocketsAddedSockets(t *testing.T) {
+	socketA := SkNode{
+		PID: 1234,
+		OpenSockets: []SocketNode{
+			{
+				Protocol: "TCP",
+				Data: SkData{
+					Type:       "TCP",
+					Source:     "0.0.0.0",
+					SourcePort: 8080,
+					Dest:       "0.0.0.0",
+					DestPort:   0,
+				},
+			},
+		},
+	}
+
+	socketB := SkNode{
+		PID: 1234,
+		OpenSockets: []SocketNode{
+			{
+				Protocol: "TCP",
+				Data: SkData{
+					Type:       "TCP",
+					Source:     "0.0.0.0",
+					SourcePort: 8080,
+					Dest:       "0.0.0.0",
+					DestPort:   0,
+				},
+			},
+			{
+				Protocol: "TCP",
+				Data: SkData{
+					Type:       "TCP",
+					Source:     "0.0.0.0",
+					SourcePort: 8081,
+					Dest:       "0.0.0.0",
+					DestPort:   0,
+				},
+			},
+		},
+	}
+
+	result := compareSockets([]SkNode{socketA}, []SkNode{socketB})
+
+	if result == nil {
+		t.Fatal("Expected non-nil result")
+	}
+
+	if len(result.Added) != 1 {
+		t.Errorf("Expected 1 added socket, got %d", len(result.Added))
+	}
+
+	if len(result.Removed) != 0 {
+		t.Errorf("Expected 0 removed sockets, got %d", len(result.Removed))
+	}
+
+	if result.Unchanged != 1 {
+		t.Errorf("Expected 1 unchanged socket, got %d", result.Unchanged)
+	}
+
+	// verify added socket is the correct one (port 8081)
+	if result.Added[0].SrcPort != 8081 {
+		t.Errorf("Expected added socket to have port 8081, got %d", result.Added[0].SrcPort)
+	}
+}
+
+// removed sockets
+func TestCompareSocketsRemovedSockets(t *testing.T) {
+	socketA := SkNode{
+		PID: 1234,
+		OpenSockets: []SocketNode{
+			{
+				Protocol: "TCP",
+				Data: SkData{
+					Type:       "TCP",
+					Source:     "0.0.0.0",
+					SourcePort: 8080,
+					Dest:       "0.0.0.0",
+					DestPort:   0,
+				},
+			},
+			{
+				Protocol: "TCP",
+				Data: SkData{
+					Type:       "TCP",
+					Source:     "0.0.0.0",
+					SourcePort: 8081,
+					Dest:       "0.0.0.0",
+					DestPort:   0,
+				},
+			},
+		},
+	}
+
+	socketB := SkNode{
+		PID: 1234,
+		OpenSockets: []SocketNode{
+			{
+				Protocol: "TCP",
+				Data: SkData{
+					Type:       "TCP",
+					Source:     "0.0.0.0",
+					SourcePort: 8081,
+					Dest:       "0.0.0.0",
+					DestPort:   0,
+				},
+			},
+		},
+	}
+
+	result := compareSockets([]SkNode{socketA}, []SkNode{socketB})
+
+	if result == nil {
+		t.Fatal("Expected non-nil result")
+	}
+
+	if len(result.Added) != 0 {
+		t.Errorf("Expected 0 added sockets, got %d", len(result.Added))
+	}
+
+	if len(result.Removed) != 1 {
+		t.Errorf("Expected 1 removed socket, got %d", len(result.Removed))
+	}
+
+	if result.Unchanged != 1 {
+		t.Errorf("Expected 1 unchanged socket, got %d", result.Unchanged)
+	}
+
+	// verify removed socket is the correct one (port 8080)
+	if result.Removed[0].SrcPort != 8080 {
+		t.Errorf("Expected removed socket to have port 8080, got %d", result.Removed[0].SrcPort)
+	}
+}
+
+// comparing sockets from different processes
+func TestCompareSocketsMultiplePIDs(t *testing.T) {
+	socketPID1 := SkNode{
+		PID: 1,
+		OpenSockets: []SocketNode{
+			{
+				Protocol: "TCP",
+				Data: SkData{
+					Type:       "TCP",
+					Source:     "0.0.0.0",
+					SourcePort: 80,
+					Dest:       "0.0.0.0",
+					DestPort:   0,
+				},
+			},
+		},
+	}
+
+	socketPID2 := SkNode{
+		PID: 2,
+		OpenSockets: []SocketNode{
+			{
+				Protocol: "TCP",
+				Data: SkData{
+					Type:       "TCP",
+					Source:     "0.0.0.0",
+					SourcePort: 443,
+					Dest:       "0.0.0.0",
+					DestPort:   0,
+				},
+			},
+		},
+	}
+
+	result := compareSockets([]SkNode{socketPID1, socketPID2}, []SkNode{socketPID1})
+
+	if result == nil {
+		t.Fatal("Expected non-nil result")
+	}
+
+	if len(result.Removed) != 1 {
+		t.Errorf("Expected 1 removed socket (PID 2's socket), got %d", len(result.Removed))
+	}
+
+	if result.Removed[0].PID != 2 {
+		t.Errorf("Expected removed socket to be from PID 2, got PID %d", result.Removed[0].PID)
+	}
+
+	if result.Removed[0].SrcPort != 443 {
+		t.Errorf("Expected removed socket to have port 443, got %d", result.Removed[0].SrcPort)
+	}
+}
+
+// summary generation with socket changes | for test generateSummary()
+func TestGenerateSummaryWithSocketChanges(t *testing.T) {
+	result := &DiffResult{
+		ContainerName: "test-container",
+		SocketChanges: &SocketDiff{
+			Added: []SocketInfo{
+				{PID: 1, Protocol: "TCP", SrcPort: 8081},
+				{PID: 1, Protocol: "TCP", SrcPort: 8082},
+			},
+			Removed: []SocketInfo{
+				{PID: 1, Protocol: "TCP", SrcPort: 8080},
+			},
+			Unchanged: 0,
+		},
+	}
+
+	summary := generateSummary(result)
+
+	if summary == "" {
+		t.Fatal("Expected non-empty summary")
+	}
+
+	// Check that socket changes are mentioned
+	if expected := "Sockets: +2 -1"; summary != expected &&
+		(summary[len(summary)-9:] != "+2 -1" && summary[len(summary)-9:] != "2 -1") {
+		t.Logf("Summary: %s", summary)
+		//
+		if !contains(summary, "Sockets:") {
+			t.Errorf("Expected summary to contain 'Sockets:', got '%s'", summary)
+		}
+	}
+}
+
+// helper function to check if string contains substring
+func contains(s, substr string) bool {
+	return len(s) >= len(substr) && (s == substr || len(s) > len(substr) && findSubstring(s, substr))
+}
+
+func findSubstring(s, substr string) bool {
+	for i := 0; i <= len(s)-len(substr); i++ {
+		if s[i:i+len(substr)] == substr {
+			return true
+		}
+	}
+	return false
+}