cmd: test cocurrency correctness

cmd/root_test.go

@@ -0,0 +1,144 @@
+package cmd
+
+import (
+	"context"
+	"sync"
+	"sync/atomic"
+	"testing"
+	"time"
+)
+
+// Mock client to count requests
+type mockClient struct {
+	requestCount int64
+}
+
+func (m *mockClient) MakeRequest(url string) {
+	atomic.AddInt64(&m.requestCount, 1)
+	// Small delay to simulate actual request
+	time.Sleep(1 * time.Millisecond)
+}
+
+func newMockClient() *mockClient {
+	return &mockClient{}
+}
+
+func TestGoroutineSpawning(t *testing.T) {
+	tests := []struct {
+		name           string
+		goroutineCount int
+		expectedCalls  int64
+	}{
+		{
+			name:           "single goroutine",
+			goroutineCount: 1,
+			expectedCalls:  1,
+		},
+		{
+			name:           "multiple goroutines",
+			goroutineCount: 5,
+			expectedCalls:  5,
+		},
+		{
+			name:           "many goroutines",
+			goroutineCount: 10,
+			expectedCalls:  10,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			mockClient := newMockClient()
+			ctx := context.Background()
+
+			// Simulate the concurrency loop
+			wg := &sync.WaitGroup{}
+			wg.Add(tt.goroutineCount)
+
+			for range tt.goroutineCount {
+				go func() {
+					defer wg.Done()
+					select {
+					case <-ctx.Done():
+						return
+					default:
+						mockClient.MakeRequest("http://test.com")
+					}
+				}()
+			}
+
+			wg.Wait()
+
+			if mockClient.requestCount != tt.expectedCalls {
+				t.Errorf("Expected %d requests, got %d", tt.expectedCalls, mockClient.requestCount)
+			}
+		})
+	}
+}
+
+func TestConcurrencyWithContext(t *testing.T) {
+	mockClient := newMockClient()
+	ctx, cancel := context.WithCancel(context.Background())
+
+	// Cancel immediately to test cancellation behavior
+	cancel()
+
+	wg := &sync.WaitGroup{}
+	goroutineCount := 5
+	wg.Add(goroutineCount)
+
+	for range goroutineCount {
+		go func() {
+			defer wg.Done()
+			select {
+			case <-ctx.Done():
+				return
+			default:
+				mockClient.MakeRequest("http://test.com")
+			}
+		}()
+	}
+
+	wg.Wait()
+
+	// Since context is cancelled, no requests should be made
+	if mockClient.requestCount != 0 {
+		t.Errorf("Expected 0 requests due to cancellation, got %d", mockClient.requestCount)
+	}
+}
+
+func TestConcurrencyTiming(t *testing.T) {
+	mockClient := newMockClient()
+	ctx := context.Background()
+	goroutineCount := 3
+
+	start := time.Now()
+	wg := &sync.WaitGroup{}
+	wg.Add(goroutineCount)
+
+	for range goroutineCount {
+		go func() {
+			defer wg.Done()
+			select {
+			case <-ctx.Done():
+				return
+			default:
+				// Simulate a 5ms request
+				time.Sleep(5 * time.Millisecond)
+				mockClient.MakeRequest("http://test.com")
+			}
+		}()
+	}
+
+	wg.Wait()
+	duration := time.Since(start)
+
+	// With 3 concurrent goroutines, total time should be roughly 5ms, not 15ms
+	if duration > 10*time.Millisecond {
+		t.Errorf("Concurrent execution took too long: %v, expected around 5ms", duration)
+	}
+
+	if mockClient.requestCount != int64(goroutineCount) {
+		t.Errorf("Expected %d requests, got %d", goroutineCount, mockClient.requestCount)
+	}
+}