test(peers): add comprehensive peer cache tests

Includes tests for peer retrieval, cache saving with and without a valid path, and cache persistence. Ensures no panic occurs during edge cases.

Author: mrz1836

client_peers_test.go

@@ -0,0 +1,290 @@
+package p2p
+
+import (
+	"encoding/json"
+	"os"
+	"path/filepath"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestClientGetPeersWithTopicPeers(t *testing.T) {
+	privKey1, err := GeneratePrivateKey()
+	require.NoError(t, err)
+
+	config1 := Config{
+		Name:       "peer1",
+		PrivateKey: privKey1,
+	}
+
+	client1, err := NewClient(config1)
+	require.NoError(t, err)
+	defer func() {
+		closeErr := client1.Close()
+		require.NoError(t, closeErr)
+	}()
+
+	// Initially should have no peers
+	peers := client1.GetPeers()
+	assert.Empty(t, peers)
+
+	// Subscribe to a topic
+	_ = client1.Subscribe("test-topic")
+
+	// Give subscription time to initialize
+	time.Sleep(100 * time.Millisecond)
+
+	// Still should have no peers (no other clients)
+	peers = client1.GetPeers()
+	assert.NotNil(t, peers)
+}
+
+func TestClientGetPeersReturnsCorrectStructure(t *testing.T) {
+	privKey, err := GeneratePrivateKey()
+	require.NoError(t, err)
+
+	config := Config{
+		Name:       testPeerName,
+		PrivateKey: privKey,
+	}
+
+	cl, err := NewClient(config)
+	require.NoError(t, err)
+	defer func() {
+		closeErr := cl.Close()
+		require.NoError(t, closeErr)
+	}()
+
+	peers := cl.GetPeers()
+
+	// Should return empty slice, not nil
+	assert.NotNil(t, peers)
+	assert.IsType(t, []PeerInfo{}, peers)
+}
+
+func TestClientSavePeerCacheDisabled(t *testing.T) {
+	privKey, err := GeneratePrivateKey()
+	require.NoError(t, err)
+
+	config := Config{
+		Name:          testPeerName,
+		PrivateKey:    privKey,
+		PeerCacheFile: "", // Cache disabled
+	}
+
+	cl, err := NewClient(config)
+	require.NoError(t, err)
+	defer func() {
+		closeErr := cl.Close()
+		require.NoError(t, closeErr)
+	}()
+
+	c := cl.(*client)
+
+	// Should not panic when caching is disabled
+	c.savePeerCache()
+}
+
+func TestClientSavePeerCacheEnabled(t *testing.T) {
+	privKey, err := GeneratePrivateKey()
+	require.NoError(t, err)
+
+	cacheFile := filepath.Join(t.TempDir(), "peers_save.json")
+
+	config := Config{
+		Name:          testPeerName,
+		PrivateKey:    privKey,
+		PeerCacheFile: cacheFile,
+	}
+
+	cl, err := NewClient(config)
+	require.NoError(t, err)
+	defer func() {
+		closeErr := cl.Close()
+		require.NoError(t, closeErr)
+	}()
+
+	c := cl.(*client)
+
+	// Subscribe to a topic to initialize topics map
+	_ = c.Subscribe("test-topic")
+	time.Sleep(100 * time.Millisecond)
+
+	// Call savePeerCache
+	c.savePeerCache()
+
+	// If there are no connected peers, cache file may or may not exist
+	// This is acceptable behavior - just verify no panic occurred
+}
+
+func TestClientSavePeerCacheWithInvalidPath(t *testing.T) {
+	privKey, err := GeneratePrivateKey()
+	require.NoError(t, err)
+
+	// Use an invalid path that cannot be written
+	invalidPath := "/nonexistent/directory/peers.json"
+
+	config := Config{
+		Name:          testPeerName,
+		PrivateKey:    privKey,
+		PeerCacheFile: invalidPath,
+	}
+
+	cl, err := NewClient(config)
+	require.NoError(t, err)
+	defer func() {
+		closeErr := cl.Close()
+		require.NoError(t, closeErr)
+	}()
+
+	c := cl.(*client)
+
+	// Subscribe to a topic
+	_ = c.Subscribe("test-topic")
+	time.Sleep(50 * time.Millisecond)
+
+	// Should not panic even with invalid path
+	c.savePeerCache()
+}
+
+func TestClientPeerCachePersistence(t *testing.T) {
+	cacheFile := filepath.Join(t.TempDir(), "peers_persist.json")
+
+	// Pre-populate cache with a peer
+	cachedPeers := []cachedPeer{
+		{
+			ID:       "QmYyQSo1c1Ym7orWxLYvCrM2EmxFTANf8wXmmE7DWjhx5N",
+			Name:     "existing-peer",
+			Addrs:    []string{"/ip4/127.0.0.1/tcp/4001"},
+			LastSeen: time.Now(),
+		},
+	}
+
+	data, err := json.MarshalIndent(cachedPeers, "", "  ")
+	require.NoError(t, err)
+	err = os.WriteFile(cacheFile, data, 0o600)
+	require.NoError(t, err)
+
+	privKey, err := GeneratePrivateKey()
+	require.NoError(t, err)
+
+	config := Config{
+		Name:          testPeerName,
+		PrivateKey:    privKey,
+		PeerCacheFile: cacheFile,
+		PeerCacheTTL:  24 * time.Hour,
+	}
+
+	// Create client - should load cached peers
+	cl, err := NewClient(config)
+	require.NoError(t, err)
+	defer func() {
+		closeErr := cl.Close()
+		require.NoError(t, closeErr)
+	}()
+
+	// Give time for cache loading
+	time.Sleep(100 * time.Millisecond)
+
+	// Verify cache file still exists
+	_, err = os.Stat(cacheFile)
+	require.NoError(t, err)
+}
+
+func TestClientSavePeerCacheMergesExistingData(t *testing.T) {
+	cacheFile := filepath.Join(t.TempDir(), "peers_merge.json")
+
+	// Pre-populate cache
+	existingPeers := []cachedPeer{
+		{
+			ID:       "QmYyQSo1c1Ym7orWxLYvCrM2EmxFTANf8wXmmE7DWjhx5N",
+			Name:     "old-peer",
+			Addrs:    []string{"/ip4/192.168.1.1/tcp/4001"},
+			LastSeen: time.Now().Add(-48 * time.Hour),
+		},
+	}
+
+	data, err := json.MarshalIndent(existingPeers, "", "  ")
+	require.NoError(t, err)
+	err = os.WriteFile(cacheFile, data, 0o600)
+	require.NoError(t, err)
+
+	privKey, err := GeneratePrivateKey()
+	require.NoError(t, err)
+
+	config := Config{
+		Name:          testPeerName,
+		PrivateKey:    privKey,
+		PeerCacheFile: cacheFile,
+	}
+
+	cl, err := NewClient(config)
+	require.NoError(t, err)
+	defer func() {
+		closeErr := cl.Close()
+		require.NoError(t, closeErr)
+	}()
+
+	c := cl.(*client)
+
+	// Subscribe to trigger topic creation
+	_ = c.Subscribe("test-topic")
+	time.Sleep(50 * time.Millisecond)
+
+	// Save cache
+	c.savePeerCache()
+}
+
+func TestClientGetPeersConcurrency(t *testing.T) {
+	privKey, err := GeneratePrivateKey()
+	require.NoError(t, err)
+
+	config := Config{
+		Name:       testPeerName,
+		PrivateKey: privKey,
+	}
+
+	cl, err := NewClient(config)
+	require.NoError(t, err)
+	defer func() {
+		closeErr := cl.Close()
+		require.NoError(t, closeErr)
+	}()
+
+	// Call GetPeers concurrently from multiple goroutines
+	done := make(chan bool)
+	for i := 0; i < 10; i++ {
+		go func() {
+			_ = cl.GetPeers()
+			done <- true
+		}()
+	}
+
+	// Wait for all goroutines
+	for i := 0; i < 10; i++ {
+		<-done
+	}
+}
+
+func TestClientPeerCacheTTLNegativeValue(t *testing.T) {
+	cacheFile := filepath.Join(t.TempDir(), "peers_ttl.json")
+
+	privKey, err := GeneratePrivateKey()
+	require.NoError(t, err)
+
+	config := Config{
+		Name:          testPeerName,
+		PrivateKey:    privKey,
+		PeerCacheFile: cacheFile,
+		PeerCacheTTL:  -1, // Negative TTL disables eviction
+	}
+
+	cl, err := NewClient(config)
+	require.NoError(t, err)
+
+	err = cl.Close()
+	require.NoError(t, err)
+}