fix(cli): use quartz clock in waitForTaskIdle for immediate first poll (#25648)

waitForTaskIdle used time.NewTicker(5s) which delays the first poll
by 5 seconds. Debugger tracing proved the failure mechanism: on slow
CI (Windows), the first poll at 5s sees "working" (idle patch has not
landed due to goroutine scheduling), needs poll #2 at 10s, but the
25s context expires before it fires.

Two changes:

1. Use r.clock.NewTicker (quartz) with time.Nanosecond initial
   interval and Reset(5s) for immediate first poll. Tests inject a
   mock clock via clitest.NewWithClock for deterministic control.
2. Rewrite WaitsForWorkingAppState test with quartz traps
   (NewTicker + TickerReset) for deterministic synchronization
   instead of racing goroutines. Fix PausedDuringWaitForReady
   sync point.

Closes DEVEX-381

cli/task_send.go

@@ -11,6 +11,7 @@ import (
 
 	"github.com/coder/coder/v2/cli/cliui"
 	"github.com/coder/coder/v2/codersdk"
+	"github.com/coder/quartz"
 	"github.com/coder/serpent"
 )
 
@@ -107,7 +108,7 @@ func (r *RootCmd) taskSend() *serpent.Command {
 				return xerrors.Errorf("task %q has status %s and cannot be sent input", display, task.Status)
 			}
 
-			if err := waitForTaskIdle(ctx, inv, client, task, workspaceBuildID); err != nil {
+			if err := waitForTaskIdle(ctx, inv, r.clock, client, task, workspaceBuildID); err != nil {
 				return xerrors.Errorf("wait for task %q to be idle: %w", display, err)
 			}
 
@@ -126,7 +127,7 @@ func (r *RootCmd) taskSend() *serpent.Command {
 // then polls until the task becomes active and its app state is idle.
 // This merges build-watching and idle-polling into a single loop so
 // that status changes (e.g. paused) are never missed between phases.
-func waitForTaskIdle(ctx context.Context, inv *serpent.Invocation, client *codersdk.Client, task codersdk.Task, workspaceBuildID uuid.UUID) error {
+func waitForTaskIdle(ctx context.Context, inv *serpent.Invocation, clk quartz.Clock, client *codersdk.Client, task codersdk.Task, workspaceBuildID uuid.UUID) error {
 	if workspaceBuildID != uuid.Nil {
 		if err := cliui.WorkspaceBuild(ctx, inv.Stdout, client, workspaceBuildID); err != nil {
 			return xerrors.Errorf("watch workspace build: %w", err)
@@ -162,13 +163,15 @@ func waitForTaskIdle(ctx context.Context, inv *serpent.Invocation, client *coder
 	// TODO(DanielleMaywood):
 	// When we have a streaming Task API, this should be converted
 	// away from polling.
-	ticker := time.NewTicker(5 * time.Second)
+	const pollInterval = 5 * time.Second
+	ticker := clk.NewTicker(time.Nanosecond, "task_send", "poll")
 	defer ticker.Stop()
 	for {
 		select {
 		case <-ctx.Done():
 			return ctx.Err()
 		case <-ticker.C:
+			ticker.Reset(pollInterval, "task_send", "poll")
 			task, err := client.TaskByID(ctx, task.ID)
 			if err != nil {
 				return xerrors.Errorf("get task by id: %w", err)

cli/task_send_test.go

@@ -21,6 +21,7 @@ import (
 	"github.com/coder/coder/v2/codersdk/agentsdk"
 	"github.com/coder/coder/v2/pty/ptytest"
 	"github.com/coder/coder/v2/testutil"
+	"github.com/coder/quartz"
 )
 
 func Test_TaskSend(t *testing.T) {
@@ -255,10 +256,10 @@ func Test_TaskSend(t *testing.T) {
 		w := clitest.StartWithWaiter(t, inv)
 
 		// Wait for the command to enter the build-watching phase
-		// of waitForTaskReady.
-		pty.ExpectMatchContext(ctx, "Queued")
+		// of waitForTaskIdle.
+		pty.ExpectMatchContext(ctx, "Waiting for task to become idle")
 
-		// Pause the task while waitForTaskReady is polling. Since
+		// Pause the task while waitForTaskIdle is polling. Since
 		// no agent is connected, the task stays initializing until
 		// we pause it, at which point the status becomes paused.
 		pauseTask(ctx, t, setup.userClient, setup.task)
@@ -284,14 +285,32 @@ func Test_TaskSend(t *testing.T) {
 			Message: "busy",
 		}))
 
+		// Set up mock clock and traps before starting the command.
+		mClock := quartz.NewMock(t)
+		tickTrap := mClock.Trap().NewTicker("task_send", "poll")
+		resetTrap := mClock.Trap().TickerReset("task_send", "poll")
+
 		// When: We send input while the app is working.
-		inv, root := clitest.New(t, "task", "send", setup.task.Name, "some task input")
+		inv, root := clitest.NewWithClock(t, mClock, "task", "send", setup.task.Name, "some task input")
 		clitest.SetupConfig(t, setup.userClient, root)
 
 		ctx := testutil.Context(t, testutil.WaitLong)
 		inv = inv.WithContext(ctx)
 		w := clitest.StartWithWaiter(t, inv)
 
+		// Wait for ticker creation and release it.
+		tickCall := tickTrap.MustWait(ctx)
+		tickCall.MustRelease(ctx)
+		tickTrap.Close()
+
+		// Fire the immediate first poll (time.Nanosecond initial interval).
+		mClock.Advance(time.Nanosecond).MustWait(ctx)
+
+		// Wait for Reset (confirms first poll completed and saw "working").
+		resetCall := resetTrap.MustWait(ctx)
+		resetCall.MustRelease(ctx)
+		resetTrap.Close()
+
 		// Transition the app back to idle so waitForTaskIdle proceeds.
 		require.NoError(t, agentClient.PatchAppStatus(ctx, agentsdk.PatchAppStatus{
 			AppSlug: "task-sidebar",
@@ -299,6 +318,9 @@ func Test_TaskSend(t *testing.T) {
 			Message: "ready",
 		}))
 
+		// Fire second poll at the regular 5s interval.
+		mClock.Advance(5 * time.Second).MustWait(ctx)
+
 		// Then: The command should complete successfully.
 		require.NoError(t, w.Wait())
 	})