tast-tests: Add ui.ChromeSanity test.

It is a test for the chrome support package.

BUG=chromium:1020484
TEST=tast run betty ui.ChromeSanity

Change-Id: Icc13f8c7b1f95bf0edb89b4caf1b720b1c5fc4cb
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/tast-tests/+/1903151
Tested-by: Shuhei Takahashi <nya@chromium.org>
Commit-Queue: Shuhei Takahashi <nya@chromium.org>
Reviewed-by: Hidehiko Abe <hidehiko@chromium.org>

src/chromiumos/tast/local/bundles/cros/ui/chrome_sanity.go

@@ -0,0 +1,106 @@
+// Copyright 2019 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package ui
+
+import (
+	"context"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"time"
+
+	"golang.org/x/sync/errgroup"
+
+	"chromiumos/tast/errors"
+	"chromiumos/tast/local/chrome"
+	"chromiumos/tast/testing"
+)
+
+func init() {
+	testing.AddTest(&testing.Test{
+		Func: ChromeSanity,
+		Desc: "Sanity tests for the chrome support library",
+		Contacts: []string{
+			"nya@chromium.org",
+			"tast-owners@google.com",
+		},
+		Attr:         []string{"group:mainline", "informational"},
+		SoftwareDeps: []string{"chrome"},
+		Pre:          chrome.LoggedIn(),
+		Timeout:      30 * time.Second,
+	})
+}
+
+func ChromeSanity(ctx context.Context, s *testing.State) {
+	cr := s.PreValue().(*chrome.Chrome)
+
+	testConcurrentTabs(ctx, s, cr)
+}
+
+// testConcurrentTabs opens and closes tabs concurrently and checks errors.
+func testConcurrentTabs(ctx context.Context, s *testing.State, cr *chrome.Chrome) {
+	const (
+		timeout     = 10 * time.Second
+		concurrency = 10
+		pageText    = "OK"
+	)
+
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		io.WriteString(w, pageText)
+	}))
+	defer srv.Close()
+
+	done := make(chan struct{}) // closed on timeout
+	go func() {
+		testing.Sleep(ctx, timeout)
+		close(done)
+	}()
+
+	// Start goroutines that opens and closes tabs concurrently.
+	g, ctx := errgroup.WithContext(ctx)
+	for i := 0; i < concurrency; i++ {
+		g.Go(func() error {
+			for {
+				// Check if timeout is already passed.
+				select {
+				case <-done:
+					return nil
+				default:
+				}
+
+				if err := func() (retErr error) {
+					conn, err := cr.NewConn(ctx, srv.URL)
+					if err != nil {
+						return errors.Wrap(err, "Chrome.NewConn failed")
+					}
+					defer func() {
+						if err := conn.Close(); err != nil && retErr == nil {
+							retErr = errors.Wrap(err, "Conn.Close failed")
+						}
+					}()
+
+					var s string
+					if err := conn.Eval(ctx, "document.documentElement.innerText", &s); err != nil {
+						return errors.Wrap(err, "Conn.Eval failed")
+					}
+					if s != pageText {
+						return errors.Errorf("unexpected page context: got %q, want %q", s, pageText)
+					}
+
+					if err := conn.CloseTarget(ctx); err != nil {
+						return errors.Wrap(err, "Conn.CloseTarget failed")
+					}
+					return nil
+				}(); err != nil {
+					return err
+				}
+			}
+		})
+	}
+
+	if err := g.Wait(); err != nil {
+		s.Error("testConcurrentTabs failed: ", err)
+	}
+}