src/chromiumos/tast/local/bundles/cros/lacros/variation_smoke.go

// Copyright 2022 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 lacros tests lacros-chrome running on ChromeOS.
package lacros

import (
	"context"
	"encoding/json"
	"io/ioutil"
	"os"
	"strings"
	"time"

	"chromiumos/tast/errors"
	"chromiumos/tast/local/apps"
	"chromiumos/tast/local/chrome"
	"chromiumos/tast/local/chrome/ash"
	"chromiumos/tast/local/chrome/browser"
	"chromiumos/tast/local/chrome/lacros"
	"chromiumos/tast/local/chrome/localstate"
	"chromiumos/tast/local/variations"
	"chromiumos/tast/testing"
)

func init() {
	testing.AddTest(&testing.Test{
		Func:         VariationSmoke,
		LacrosStatus: testing.LacrosVariantExists,
		Desc:         "Checks that Lacros doesn't crash and basic web content rendering is functional when loading a given variations seed",
		Contacts:     []string{"yjt@google.com", "lacros-team@google.com", "chromeos-sw-engprod@google.com"},
		Attr:         []string{"group:mainline", "informational"},
		SoftwareDeps: []string{"chrome", "lacros"},
		Fixture:      "lacrosVariationEnabled",
		Timeout:      5 * time.Minute,
		Data:         []string{"variation_seed.json"},
	})
}

// Constants for the path to CrOS' Lacros Local State file and the pref names for controlling the variations config.
const (
	localStatePath = lacros.UserDataDir + "/Local State"
)

// readVariationsSeed reads the current variations seed from the Local State file.
func readVariationsSeed(ctx context.Context) (*variations.SeedData, error) {
	seedVal, err := localstate.UnmarshalPref(browser.TypeLacros, variations.CompressedSeedPref)
	if err != nil {
		return nil, errors.Errorf("%v field not found in Local State", variations.CompressedSeedPref)
	}
	seed, ok := seedVal.(string)
	if !ok {
		return nil, errors.Errorf("%v field has an unexpected value type in Local State", variations.CompressedSeedPref)
	}
	signatureVal, err := localstate.UnmarshalPref(browser.TypeLacros, variations.SeedSignaturePref)
	if err != nil {
		return nil, errors.Errorf("%v field not found in Local State", variations.SeedSignaturePref)
	}
	signature, ok := signatureVal.(string)
	if !ok {
		return nil, errors.Errorf("%v field has an unexpected value type in Local State", variations.SeedSignaturePref)
	}
	return &variations.SeedData{CompressedSeed: seed, SeedSignature: signature}, nil
}

// injectSeedInLocalState injects the given seed into Local State. The seed will be loaded and take effect on the next run of Lacros.
func injectSeedInLocalState(ctx context.Context, seed *variations.SeedData) error {
	if err := localstate.MarshalPref(browser.TypeLacros, variations.CompressedSeedPref, seed.CompressedSeed); err != nil {
		return errors.Wrapf(err, "failed to write Local State with %s", variations.CompressedSeedPref)
	}
	if err := localstate.MarshalPref(browser.TypeLacros, variations.SeedSignaturePref, seed.SeedSignature); err != nil {
		return errors.Wrapf(err, "failed to write Local State with %s", variations.SeedSignaturePref)
	}
	return nil
}

func VariationSmoke(ctx context.Context, s *testing.State) {
	// Prepare the test seed.
	testSeedFile, err := os.Open(s.DataPath("variation_seed.json"))
	if err != nil {
		s.Fatal("Failed to open test seed file: ", err)
	}
	defer testSeedFile.Close()
	b, err := ioutil.ReadAll(testSeedFile)
	if err != nil {
		s.Fatal("Failed to read Local State file contents: ", err)
	}
	var testSeed variations.SeedData
	if err := json.Unmarshal(b, &testSeed); err != nil {
		s.Fatal("Failed to unmarshal test seed: ", err)
	}
	tconn, err := s.FixtValue().(chrome.HasChrome).Chrome().TestAPIConn(ctx)
	if err != nil {
		s.Fatal("Failed to connect to test API: ", err)
	}
	func() {
		l, err := lacros.Launch(ctx, tconn)
		if err != nil {
			s.Fatal("Failed to launch lacros: ", err)
		}
		// Close the lacros, close ash app first
		defer ash.WaitForAppClosed(ctx, tconn, apps.Lacros.ID)
		defer l.Close(ctx)

		if err := testing.Poll(ctx, func(context.Context) error {
			if _, err := readVariationsSeed(ctx); err != nil {
				return errors.Wrap(err, "production variations seed not yet fetched")
			}
			return nil
		}, &testing.PollOptions{Interval: time.Second, Timeout: time.Minute}); err != nil {
			s.Fatal("Production variations seed not fetched: ", err)
		}
		if err := injectSeedInLocalState(ctx, &testSeed); err != nil {
			s.Fatal("Failed to inject test seed: ", err)
		}
		// Ensure the seed was injected. There is no waiting time required because it will not download the seed.
		currentSeed, err := readVariationsSeed(ctx)
		if err != nil {
			s.Fatal("Failed to read variations seed info")
		}
		if currentSeed.CompressedSeed != testSeed.CompressedSeed || currentSeed.SeedSignature != testSeed.SeedSignature {
			s.Fatal("Local State has not updated with the test seed")
		}
	}()

	func() {
		l, err := lacros.Launch(ctx, tconn)
		if err != nil {
			s.Fatal("Failed to launch lacros: ", err)
		}
		// Close the lacros, close ash app first
		defer ash.WaitForAppClosed(ctx, tconn, apps.Lacros.ID)
		defer l.Close(ctx)

		// Navigate to some pages in Chrome and verify that web elements are rendered correctly.
		type tc struct {
			url     string
			text    string
			content string
		}
		tests := []tc{
			{
				//data:text/html,<h1 id="success">Success</h1>
				url:     "data:text/html,%3Ch1%20id%3D%22success%22%3ESuccess%3C%2Fh1%3E",
				text:    "Success",
				content: "<h1 id=\"success\">Success</h1>",
			},
			{
				// TODO(crbug.com/1234165): Make tests hermetic by using a test http server.
				url:     "https://chromium.org/",
				text:    "The Chromium Projects",
				content: "<h2>The Chromium Projects</h2>",
			},
		}

		for _, t := range tests {
			c, err := l.NewConn(ctx, t.url)
			if err != nil {
				s.Fatalf("Failed to open Lacros with URL %v: %v", t.url, err)
			}
			defer c.Close()
			pageContent, err := c.PageContent(ctx)
			if err != nil {
				s.Fatal("Failed to obtain the page content")
			}

			if !strings.Contains(pageContent, t.content) {
				s.Fatalf("Failed to find text %q on page %q with correct format", t.text, t.url)
			}
		}

		// Verify that Lacros has downloaded and updated the variations seed. Poll to allow some time for downloading the seed.
		if err := testing.Poll(ctx, func(context.Context) error {
			currentSeed, err := readVariationsSeed(ctx)
			if err != nil {
				return errors.Wrap(err, "failed to read variations seed info")
			}
			if currentSeed.CompressedSeed == testSeed.CompressedSeed || currentSeed.SeedSignature == testSeed.SeedSignature {
				return errors.New("Lacros did not update the variations seed")
			}
			return nil
		}, nil); err != nil {
			s.Fatal("Failed to download the seed: ", err)
		}
	}()
}