add request buffer for nmap data store

management/internals/shared/requestbuffer/buffer_test.go

@@ -0,0 +1,106 @@
+package requestbuffer
+
+import (
+	"context"
+	"errors"
+	"sync"
+	"sync/atomic"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestBufferCoalescesConcurrentRequests(t *testing.T) {
+	var fetches atomic.Int32
+	buffer := New(context.Background(), "test", 50*time.Millisecond,
+		func(ctx context.Context, key string) (string, error) {
+			fetches.Add(1)
+			return key, nil
+		})
+
+	var wg sync.WaitGroup
+	for range 10 {
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			value, err := buffer.Get(context.Background(), "account")
+			assert.NoError(t, err)
+			assert.Equal(t, "account", value)
+		}()
+	}
+	wg.Wait()
+
+	assert.Equal(t, int32(1), fetches.Load())
+}
+
+func TestBufferSeparatesKeys(t *testing.T) {
+	keys := make(chan string, 2)
+	buffer := New(context.Background(), "test", 10*time.Millisecond,
+		func(ctx context.Context, key string) (string, error) {
+			keys <- key
+			return key, nil
+		})
+
+	var wg sync.WaitGroup
+	for _, key := range []string{"a", "b"} {
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			_, err := buffer.Get(context.Background(), key)
+			assert.NoError(t, err)
+		}()
+	}
+	wg.Wait()
+	close(keys)
+
+	var fetched []string
+	for key := range keys {
+		fetched = append(fetched, key)
+	}
+	assert.ElementsMatch(t, []string{"a", "b"}, fetched)
+}
+
+func TestBufferFetchesAfterRequest(t *testing.T) {
+	var version atomic.Int32
+	buffer := New(context.Background(), "test", 10*time.Millisecond,
+		func(ctx context.Context, key string) (int32, error) {
+			return version.Load(), nil
+		})
+
+	first, err := buffer.Get(context.Background(), "account")
+	require.NoError(t, err)
+	assert.Equal(t, int32(0), first)
+
+	version.Store(1)
+
+	second, err := buffer.Get(context.Background(), "account")
+	require.NoError(t, err)
+	assert.Equal(t, int32(1), second)
+}
+
+func TestBufferPropagatesError(t *testing.T) {
+	fetchErr := errors.New("fetch failed")
+	buffer := New(context.Background(), "test", 10*time.Millisecond,
+		func(ctx context.Context, key string) (*int, error) {
+			return nil, fetchErr
+		})
+
+	value, err := buffer.Get(context.Background(), "account")
+	assert.ErrorIs(t, err, fetchErr)
+	assert.Nil(t, value)
+}
+
+func TestBufferHonorsCallerContext(t *testing.T) {
+	buffer := New(context.Background(), "test", time.Minute,
+		func(ctx context.Context, key string) (string, error) {
+			return key, nil
+		})
+
+	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Millisecond)
+	defer cancel()
+
+	_, err := buffer.Get(ctx, "account")
+	assert.ErrorIs(t, err, context.DeadlineExceeded)
+}