From d6e10d36f68ab87f741953ac269d90fdd7849002 Mon Sep 17 00:00:00 2001
From: Matt Dale <9760375+matthewdale@users.noreply.github.com>
Date: Thu, 4 Apr 2024 17:03:42 -0700
Subject: [PATCH] Test that durations are included on relevant pool events.

---
 x/mongo/driver/topology/pool_test.go | 75 ++++++++++++++++++++++++++++
 1 file changed, 75 insertions(+)

diff --git a/x/mongo/driver/topology/pool_test.go b/x/mongo/driver/topology/pool_test.go
index 013403981d..ab7b38d956 100644
--- a/x/mongo/driver/topology/pool_test.go
+++ b/x/mongo/driver/topology/pool_test.go
@@ -14,7 +14,10 @@ import (
 	"testing"
 	"time"
 
+	"go.mongodb.org/mongo-driver/event"
 	"go.mongodb.org/mongo-driver/internal/assert"
+	"go.mongodb.org/mongo-driver/internal/eventtest"
+	"go.mongodb.org/mongo-driver/internal/require"
 	"go.mongodb.org/mongo-driver/mongo/address"
 	"go.mongodb.org/mongo-driver/x/mongo/driver/operation"
 )
@@ -1157,3 +1160,75 @@ func assertConnectionsOpened(t *testing.T, dialer *dialer, count int) {
 		time.Sleep(100 * time.Millisecond)
 	}
 }
+
+func TestPool_PoolMonitor(t *testing.T) {
+	t.Parallel()
+
+	t.Run("records durations", func(t *testing.T) {
+		t.Parallel()
+
+		cleanup := make(chan struct{})
+		defer close(cleanup)
+
+		// Create a listener that responds to exactly 1 connection. All
+		// subsequent connection requests should fail.
+		addr := bootstrapConnections(t, 1, func(nc net.Conn) {
+			<-cleanup
+			_ = nc.Close()
+		})
+
+		tpm := eventtest.NewTestPoolMonitor()
+		p := newPool(poolConfig{
+			Address:     address.Address(addr.String()),
+			PoolMonitor: tpm.PoolMonitor,
+		})
+
+		err := p.ready()
+		require.NoError(t, err, "ready error")
+
+		// Check out a connection to trigger "ConnectionReady" and
+		// "ConnectionCheckedOut" events.
+		conn, err := p.checkOut(context.Background())
+		require.NoError(t, err, "checkOut error")
+
+		// Close the connection so the next checkOut tries to create a new
+		// connection.
+		err = conn.close()
+		require.NoError(t, err, "close error")
+
+		err = p.checkIn(conn)
+		require.NoError(t, err, "checkIn error")
+
+		// Try to check out another connection to trigger a
+		// "ConnectionCheckOutFailed" event.
+		_, err = p.checkOut(context.Background())
+		require.Error(t, err, "expected a checkOut error")
+
+		p.close(context.Background())
+
+		events := tpm.Events(func(evt *event.PoolEvent) bool {
+			switch evt.Type {
+			case "ConnectionReady", "ConnectionCheckedOut", "ConnectionCheckOutFailed":
+				return true
+			}
+			return false
+		})
+
+		require.Lenf(t, events, 3, "expected there to be 3 pool events")
+
+		assert.Equal(t, events[0].Type, "ConnectionReady")
+		assert.Positive(t,
+			events[0].Duration,
+			"expected ConnectionReady Duration to be set")
+
+		assert.Equal(t, events[1].Type, "ConnectionCheckedOut")
+		assert.Positive(t,
+			events[1].Duration,
+			"expected ConnectionCheckedOut Duration to be set")
+
+		assert.Equal(t, events[2].Type, "ConnectionCheckOutFailed")
+		assert.Positive(t,
+			events[2].Duration,
+			"expected ConnectionCheckOutFailed Duration to be set")
+	})
+}