Various performance and correctness improvements.

queue/queue_test.go

@@ -0,0 +1,104 @@
+package queue
+
+import (
+	"context"
+	"git.wisehodl.dev/jay/go-honeybee/honeybeetest"
+	"git.wisehodl.dev/jay/go-honeybee/types"
+	"github.com/stretchr/testify/assert"
+	"testing"
+	"time"
+)
+
+func TestRunQueue(t *testing.T) {
+	t.Run("message passes through to inbox", func(t *testing.T) {
+		id := "wss://test"
+		inChan := make(chan types.ReceivedMessage, 1)
+		outChan := make(chan types.ReceivedMessage, 1)
+		ctx, cancel := context.WithCancel(context.Background())
+		defer cancel()
+
+		go RunQueue(id, ctx, inChan, outChan, 0)
+
+		inChan <- types.ReceivedMessage{Data: []byte("hello"), ReceivedAt: time.Now()}
+
+		honeybeetest.Eventually(t, func() bool {
+			select {
+			case msg := <-outChan:
+				return string(msg.Data) == "hello"
+			default:
+				return false
+			}
+		}, "expected message")
+	})
+
+	t.Run("oldest message dropped when queue is full", func(t *testing.T) {
+		id := "wss://test"
+		inChan := make(chan types.ReceivedMessage, 1)
+		outChan := make(chan types.ReceivedMessage, 1)
+		ctx, cancel := context.WithCancel(context.Background())
+		defer cancel()
+
+		gate := make(chan struct{})
+		gatedInbox := make(chan types.ReceivedMessage)
+
+		// gate the inbox from receiving messages until the gate is opened
+		go func() {
+			<-gate
+			for msg := range gatedInbox {
+				outChan <- msg
+			}
+		}()
+
+		go RunQueue(id, ctx, inChan, gatedInbox, 2)
+
+		// send three messages while the gated inbox is blocked
+		inChan <- types.ReceivedMessage{Data: []byte("first"), ReceivedAt: time.Now()}
+		inChan <- types.ReceivedMessage{Data: []byte("second"), ReceivedAt: time.Now()}
+		inChan <- types.ReceivedMessage{Data: []byte("third"), ReceivedAt: time.Now()}
+
+		// allow time for the first message to be dropped
+		time.Sleep(20 * time.Millisecond)
+
+		// close the gate, draining messages into the inbox
+		close(gate)
+
+		// receive messages from the inbox
+		var received []string
+		honeybeetest.Eventually(t, func() bool {
+			select {
+			case msg := <-outChan:
+				received = append(received, string(msg.Data))
+			default:
+			}
+			return len(received) == 2
+		}, "expected messages")
+
+		// first message was dropped
+		assert.Equal(t, []string{"second", "third"}, received)
+
+	})
+
+	t.Run("exits on context cancellation", func(t *testing.T) {
+		id := "wss://test"
+		inChan := make(chan types.ReceivedMessage, 1)
+		outChan := make(chan types.ReceivedMessage, 1)
+		ctx, cancel := context.WithCancel(context.Background())
+		defer cancel()
+
+		done := make(chan struct{})
+		go func() {
+			RunQueue(id, ctx, inChan, outChan, 0)
+			close(done)
+		}()
+
+		cancel()
+		honeybeetest.Eventually(t, func() bool {
+			select {
+			case <-done:
+				return true
+			default:
+				return false
+			}
+		}, "expected done signal")
+	})
+}