refactor(agent): add agenttest.New helper function (#9812)

* Adds agenttest.New() helper function
* Makes sure agent gets closed on test cleanup
* Makes sure you don't forget to set session token
* Sets the agent and client logger automatically

cli/speedtest_test.go

@@ -9,12 +9,11 @@ import (
 
 	"cdr.dev/slog"
 	"cdr.dev/slog/sloggers/slogtest"
-	"github.com/coder/coder/v2/agent"
+	"github.com/coder/coder/v2/agent/agenttest"
 	"github.com/coder/coder/v2/cli"
 	"github.com/coder/coder/v2/cli/clitest"
 	"github.com/coder/coder/v2/coderd/coderdtest"
 	"github.com/coder/coder/v2/codersdk"
-	"github.com/coder/coder/v2/codersdk/agentsdk"
 	"github.com/coder/coder/v2/pty/ptytest"
 	"github.com/coder/coder/v2/testutil"
 )
@@ -26,13 +25,7 @@ func TestSpeedtest(t *testing.T) {
 		t.Skip("This test takes a minimum of 5ms per a hardcoded value in Tailscale!")
 	}
 	client, workspace, agentToken := setupWorkspaceForAgent(t, nil)
-	agentClient := agentsdk.New(client.URL)
-	agentClient.SetSessionToken(agentToken)
-	agentCloser := agent.New(agent.Options{
-		Client: agentClient,
-		Logger: slogtest.Make(t, nil).Named("agent").Leveled(slog.LevelDebug),
-	})
-	defer agentCloser.Close()
+	_ = agenttest.New(t, client.URL, agentToken)
 	coderdtest.AwaitWorkspaceAgents(t, client, workspace.ID)
 
 	ctx, cancel := context.WithTimeout(context.Background(), testutil.WaitLong)