chrome-devtools-frontend/front_end/testing/TraceHelpers.ts

Chrome DevTools UI

// Copyright 2022 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
import * as SDK from '../core/sdk/sdk.js';
import type * as Protocol from '../generated/protocol.js';
import * as Bindings from '../models/bindings/bindings.js';
import * as CPUProfile from '../models/cpu_profile/cpu_profile.js';
import * as Trace from '../models/trace/trace.js';
import * as Workspace from '../models/workspace/workspace.js';
import * as Timeline from '../panels/timeline/timeline.js';
import * as PerfUI from '../ui/legacy/components/perf_ui/perf_ui.js';

import {initializeGlobalVars} from './EnvironmentHelpers.js';
import {TraceLoader} from './TraceLoader.js';

// This mock class is used for instancing a flame chart in the helpers.
// Its implementation is empty because the methods aren't used by the
// helpers, only the mere definition.
export class MockFlameChartDelegate implements PerfUI.FlameChart.FlameChartDelegate {
  windowChanged(_startTime: number, _endTime: number, _animate: boolean): void {
  }
  updateRangeSelection(_startTime: number, _endTime: number): void {
  }
  updateSelectedGroup(_flameChart: PerfUI.FlameChart.FlameChart, _group: PerfUI.FlameChart.Group|null): void {
  }
}

/**
 * Draws a set of tracks track in the flame chart using the new system.
 * For this to work, every track that will be rendered must have a
 * corresponding track appender registered in the
 * CompatibilityTracksAppender.
 *
 * @param traceFileName The name of the trace file to be loaded into the
 * flame chart.
 * @param trackAppenderNames A Set with the names of the tracks to be
 * rendered. For example, Set("Timings").
 * @param expanded whether the track should be expanded
 * @param trackName optional param to filter tracks by their name.
 * @returns a flame chart element and its corresponding data provider.
 */
export async function getMainFlameChartWithTracks(
    traceFileName: string, trackAppenderNames: Set<Timeline.CompatibilityTracksAppender.TrackAppenderName>,
    expanded: boolean, trackName?: string): Promise<{
  flameChart: PerfUI.FlameChart.FlameChart,
  dataProvider: Timeline.TimelineFlameChartDataProvider.TimelineFlameChartDataProvider,
}> {
  await initializeGlobalVars();

  // This function is used to load a component example.
  const {parsedTrace} = await TraceLoader.traceEngine(/* context= */ null, traceFileName);

  const dataProvider = new Timeline.TimelineFlameChartDataProvider.TimelineFlameChartDataProvider();
  // The data provider still needs a reference to the legacy model to
  // work properly.
  dataProvider.setModel(parsedTrace);
  const tracksAppender = dataProvider.compatibilityTracksAppenderInstance();
  tracksAppender.setVisibleTracks(trackAppenderNames);
  dataProvider.buildFromTrackAppendersForTest(
      {filterThreadsByName: trackName, expandedTracks: expanded ? trackAppenderNames : undefined});
  const delegate = new MockFlameChartDelegate();
  const flameChart = new PerfUI.FlameChart.FlameChart(dataProvider, delegate);
  const minTime = Trace.Helpers.Timing.microToMilli(parsedTrace.Meta.traceBounds.min);
  const maxTime = Trace.Helpers.Timing.microToMilli(parsedTrace.Meta.traceBounds.max);
  flameChart.setWindowTimes(minTime, maxTime);
  flameChart.markAsRoot();
  flameChart.update();
  return {flameChart, dataProvider};
}

/**
 * Draws the network track in the flame chart using the legacy system.
 *
 * @param traceFileName The name of the trace file to be loaded to the flame
 * chart.
 * @param expanded if the track is expanded
 * @returns a flame chart element and its corresponding data provider.
 */
export async function getNetworkFlameChart(traceFileName: string, expanded: boolean): Promise<{
  flameChart: PerfUI.FlameChart.FlameChart,
  dataProvider: Timeline.TimelineFlameChartNetworkDataProvider.TimelineFlameChartNetworkDataProvider,
}> {
  await initializeGlobalVars();

  const {parsedTrace} = await TraceLoader.traceEngine(/* context= */ null, traceFileName);
  const minTime = Trace.Helpers.Timing.microToMilli(parsedTrace.Meta.traceBounds.min);
  const maxTime = Trace.Helpers.Timing.microToMilli(parsedTrace.Meta.traceBounds.max);
  const dataProvider = new Timeline.TimelineFlameChartNetworkDataProvider.TimelineFlameChartNetworkDataProvider();
  dataProvider.setModel(parsedTrace);
  dataProvider.setWindowTimes(minTime, maxTime);
  dataProvider.timelineData().groups.forEach(group => {
    group.expanded = expanded;
  });

  const delegate = new MockFlameChartDelegate();
  const flameChart = new PerfUI.FlameChart.FlameChart(dataProvider, delegate);
  flameChart.setWindowTimes(minTime, maxTime);
  flameChart.markAsRoot();
  flameChart.update();
  return {flameChart, dataProvider};
}

// We create here a cross-test base trace event. It is assumed that each
// test will import this default event and copy-override properties at will.
export const defaultTraceEvent: Trace.Types.Events.Event = {
  name: 'process_name',
  tid: Trace.Types.Events.ThreadID(0),
  pid: Trace.Types.Events.ProcessID(0),
  ts: Trace.Types.Timing.Micro(0),
  cat: 'test',
  ph: Trace.Types.Events.Phase.METADATA,
};

/**
 * Gets the tree in a thread.
 * @see RendererHandler.ts
 */
export function getTree(thread: Trace.Handlers.ModelHandlers.Renderer.RendererThread):
    Trace.Helpers.TreeHelpers.TraceEntryTree {
  const tree = thread.tree;
  if (!tree) {
    assert(false, `Couldn't get tree in thread ${thread.name}`);
  }
  return tree;
}

/**
 * Gets the n-th root from a tree in a thread.
 * @see RendererHandler.ts
 */
export function getRootAt(thread: Trace.Handlers.ModelHandlers.Renderer.RendererThread, index: number):
    Trace.Helpers.TreeHelpers.TraceEntryNode {
  const tree = getTree(thread);
  const node = [...tree.roots][index];
  if (node === undefined) {
    assert(false, `Couldn't get the id of the root at index ${index} in thread ${thread.name}`);
  }
  return node;
}

/**
 * Gets all nodes in a thread. To finish this task, we Walk through all the nodes, starting from the root node.
 */
export function getAllNodes(roots: Set<Trace.Helpers.TreeHelpers.TraceEntryNode>):
    Trace.Helpers.TreeHelpers.TraceEntryNode[] {
  const allNodes: Trace.Helpers.TreeHelpers.TraceEntryNode[] = [];

  const children: Trace.Helpers.TreeHelpers.TraceEntryNode[] = Array.from(roots);
  while (children.length > 0) {
    const childNode = children.shift();
    if (childNode) {
      allNodes.push(childNode);
      children.push(...childNode.children);
    }
  }
  return allNodes;
}

/**
 * Gets the node with an id from a tree in a thread.
 * @see RendererHandler.ts
 */
export function getNodeFor(
    thread: Trace.Handlers.ModelHandlers.Renderer.RendererThread,
    nodeId: Trace.Helpers.TreeHelpers.TraceEntryNodeId): Trace.Helpers.TreeHelpers.TraceEntryNode {
  const tree = getTree(thread);

  function findNode(
      nodes: Set<Trace.Helpers.TreeHelpers.TraceEntryNode>|Trace.Helpers.TreeHelpers.TraceEntryNode[],
      nodeId: Trace.Helpers.TreeHelpers.TraceEntryNodeId): Trace.Helpers.TreeHelpers.TraceEntryNode|undefined {
    for (const node of nodes) {
      const event = node.entry;
      if (Trace.Types.Events.isProfileCall(event) && event.nodeId === nodeId) {
        return node;
      }
      return findNode(node.children, nodeId);
    }
    return undefined;
  }
  const node = findNode(tree.roots, nodeId);
  if (!node) {
    assert(false, `Couldn't get the node with id ${nodeId} in thread ${thread.name}`);
  }
  return node;
}

/**
 * Gets all the `events` for the `nodes`.
 */
export function getEventsIn(nodes: IterableIterator<Trace.Helpers.TreeHelpers.TraceEntryNode>):
    Trace.Types.Events.Event[] {
  return [...nodes].flatMap(node => node ? node.entry : []);
}
/**
 * Pretty-prints a tree.
 */
export function prettyPrint(
    tree: Trace.Helpers.TreeHelpers.TraceEntryTree,
    predicate: (node: Trace.Helpers.TreeHelpers.TraceEntryNode, event: Trace.Types.Events.Event) => boolean = () =>
        true,
    indentation: number = 2, delimiter: string = ' ', prefix: string = '-', newline: string = '\n',
    out: string = ''): string {
  let skipped = false;
  return printNodes(tree.roots);
  function printNodes(nodes: Set<Trace.Helpers.TreeHelpers.TraceEntryNode>|
                      Trace.Helpers.TreeHelpers.TraceEntryNode[]): string {
    for (const node of nodes) {
      const event = node.entry;
      if (!predicate(node, event)) {
        out += `${!skipped ? newline : ''}.`;
        skipped = true;
        continue;
      }
      skipped = false;
      const spacing = new Array(node.depth * indentation).fill(delimiter).join('');
      const eventType = Trace.Types.Events.isDispatch(event) ? `(${event.args.data?.type})` : false;
      const jsFunctionName =
          Trace.Types.Events.isProfileCall(event) ? `(${event.callFrame.functionName || 'anonymous'})` : false;
      const duration = `[${(event.dur || 0) / 1000}ms]`;
      const info = [jsFunctionName, eventType, duration].filter(Boolean);
      out += `${newline}${spacing}${prefix}${event.name} ${info.join(' ')}`;
      out = printNodes(node.children);
    }
    return out;
  }
}

/**
 * Builds a mock Complete.
 */
export function makeCompleteEvent(
    name: string, ts: number, dur: number, cat: string = '*', pid: number = 0,
    tid: number = 0): Trace.Types.Events.Complete {
  return {
    args: {},
    cat,
    name,
    ph: Trace.Types.Events.Phase.COMPLETE,
    pid: Trace.Types.Events.ProcessID(pid),
    tid: Trace.Types.Events.ThreadID(tid),
    ts: Trace.Types.Timing.Micro(ts),
    dur: Trace.Types.Timing.Micro(dur),
  };
}

export function makeAsyncStartEvent(
    name: string,
    ts: number,
    pid: number = 0,
    tid: number = 0,
    ): Trace.Types.Events.Async {
  return {
    args: {},
    cat: '*',
    name,
    ph: Trace.Types.Events.Phase.ASYNC_NESTABLE_START,
    pid: Trace.Types.Events.ProcessID(pid),
    tid: Trace.Types.Events.ThreadID(tid),
    ts: Trace.Types.Timing.Micro(ts),
  };
}
export function makeAsyncEndEvent(
    name: string,
    ts: number,
    pid: number = 0,
    tid: number = 0,
    ): Trace.Types.Events.Async {
  return {
    args: {},
    cat: '*',
    name,
    ph: Trace.Types.Events.Phase.ASYNC_NESTABLE_END,
    pid: Trace.Types.Events.ProcessID(pid),
    tid: Trace.Types.Events.ThreadID(tid),
    ts: Trace.Types.Timing.Micro(ts),
  };
}

/**
 * Builds a mock flow phase event.
 */
export function makeFlowPhaseEvent(
    name: string, ts: number, cat: string = '*',
    ph: Trace.Types.Events.Phase.FLOW_START|Trace.Types.Events.Phase.FLOW_END|Trace.Types.Events.Phase.FLOW_STEP,
    id: number = 0, pid: number = 0, tid: number = 0): Trace.Types.Events.FlowEvent {
  return {
    args: {},
    cat,
    name,
    id,
    ph,
    pid: Trace.Types.Events.ProcessID(pid),
    tid: Trace.Types.Events.ThreadID(tid),
    ts: Trace.Types.Timing.Micro(ts),
    dur: Trace.Types.Timing.Micro(0),
  };
}

/**
 * Builds flow phase events for a list of events belonging to the same
 * flow. `events` must be ordered.
 */
export function makeFlowEvents(events: Trace.Types.Events.Event[], flowId: number = 0): Trace.Types.Events.FlowEvent[] {
  const lastEvent = events.at(-1);
  const firstEvent = events.at(0);
  if (!lastEvent || !firstEvent) {
    return [];
  }
  const flowName = events[0].name;
  const flowStart = makeFlowPhaseEvent(
      flowName, firstEvent.ts, firstEvent.cat, Trace.Types.Events.Phase.FLOW_START, flowId, firstEvent.pid,
      firstEvent.tid);
  const flowEnd = makeFlowPhaseEvent(
      flowName, lastEvent.ts, lastEvent.cat, Trace.Types.Events.Phase.FLOW_END, flowId, lastEvent.pid, lastEvent.tid);

  const flowSteps: Trace.Types.Events.FlowEvent[] = [];
  for (let i = 1; i < events.length - 1; i++) {
    flowSteps.push(makeFlowPhaseEvent(
        flowName, events[i].ts, events[i].cat, Trace.Types.Events.Phase.FLOW_STEP, flowId, events[i].pid,
        events[i].tid));
  }
  return [flowStart, ...flowSteps, flowEnd];
}

/**
 * Builds a mock Instant.
 */
export function makeInstantEvent(
    name: string, tsMicroseconds: number, cat: string = '', pid: number = 0, tid: number = 0,
    s: Trace.Types.Events.Scope = Trace.Types.Events.Scope.THREAD): Trace.Types.Events.Instant {
  return {
    args: {},
    cat,
    name,
    ph: Trace.Types.Events.Phase.INSTANT,
    pid: Trace.Types.Events.ProcessID(pid),
    tid: Trace.Types.Events.ThreadID(tid),
    ts: Trace.Types.Timing.Micro(tsMicroseconds),
    s,
  };
}

/**
 * Builds a mock Begin.
 */
export function makeBeginEvent(
    name: string, ts: number, cat: string = '*', pid: number = 0, tid: number = 0): Trace.Types.Events.Begin {
  return {
    args: {},
    cat,
    name,
    ph: Trace.Types.Events.Phase.BEGIN,
    pid: Trace.Types.Events.ProcessID(pid),
    tid: Trace.Types.Events.ThreadID(tid),
    ts: Trace.Types.Timing.Micro(ts),
  };
}

/**
 * Builds a mock End.
 */
export function makeEndEvent(
    name: string, ts: number, cat: string = '*', pid: number = 0, tid: number = 0): Trace.Types.Events.End {
  return {
    args: {},
    cat,
    name,
    ph: Trace.Types.Events.Phase.END,
    pid: Trace.Types.Events.ProcessID(pid),
    tid: Trace.Types.Events.ThreadID(tid),
    ts: Trace.Types.Timing.Micro(ts),
  };
}

export function makeProfileCall(
    functionName: string, tsUs: number, durUs: number, pid: number = 0, tid: number = 0, nodeId: number = 0,
    url: string = ''): Trace.Types.Events.SyntheticProfileCall {
  return {
    cat: '',
    name: 'ProfileCall',
    nodeId,
    sampleIndex: 0,
    profileId: Trace.Types.Events.ProfileID('fake-profile-id'),
    ph: Trace.Types.Events.Phase.COMPLETE,
    pid: Trace.Types.Events.ProcessID(pid),
    tid: Trace.Types.Events.ThreadID(tid),
    ts: Trace.Types.Timing.Micro(tsUs),
    dur: Trace.Types.Timing.Micro(durUs),
    callFrame: {
      functionName,
      scriptId: '' as Protocol.Runtime.ScriptId,
      url,
      lineNumber: -1,
      columnNumber: -1,
    },
    args: {},
  };
}
export const DevToolsTimelineCategory = 'disabled-by-default-devtools.timeline';

/**
 * Mocks an object compatible with the return type of the
 * RendererHandler using only an array of ordered entries.
 */
export function makeMockRendererHandlerData(entries: Trace.Types.Events.Event[], pid: number = 1, tid: number = 1):
    Trace.Handlers.ModelHandlers.Renderer.RendererHandlerData {
  const {tree, entryToNode} = Trace.Helpers.TreeHelpers.treify(entries, {filter: {has: () => true}});
  const mockThread: Trace.Handlers.ModelHandlers.Renderer.RendererThread = {
    tree,
    name: 'thread',
    entries,
    profileCalls: entries.filter(Trace.Types.Events.isProfileCall),
    layoutEvents: entries.filter(Trace.Types.Events.isLayout),
    updateLayoutTreeEvents: entries.filter(Trace.Types.Events.isUpdateLayoutTree),
  };

  const mockProcess: Trace.Handlers.ModelHandlers.Renderer.RendererProcess = {
    url: 'url',
    isOnMainFrame: true,
    threads: new Map([[tid as Trace.Types.Events.ThreadID, mockThread]]),
  };

  const renderereEvents: Trace.Types.Events.RendererEvent[] = [];
  for (const entry of entries) {
    if (Trace.Types.Events.isRendererEvent(entry)) {
      renderereEvents.push(entry);
    }
  }

  return {
    processes: new Map([[pid as Trace.Types.Events.ProcessID, mockProcess]]),
    compositorTileWorkers: new Map(),
    entryToNode,
    allTraceEntries: renderereEvents,
    entityMappings: {
      entityByEvent: new Map(),
      eventsByEntity: new Map(),
      createdEntityCache: new Map(),
    },
  };
}

/**
 * Mocks an object compatible with the return type of the
 * SamplesHandler using only an array of ordered profile calls.
 */
export function makeMockSamplesHandlerData(profileCalls: Trace.Types.Events.SyntheticProfileCall[]):
    Trace.Handlers.ModelHandlers.Samples.SamplesHandlerData {
  const {tree, entryToNode} = Trace.Helpers.TreeHelpers.treify(profileCalls, {filter: {has: () => true}});
  const profile: Protocol.Profiler.Profile = {
    nodes: [],
    startTime: profileCalls.at(0)?.ts || Trace.Types.Timing.Micro(0),
    endTime: profileCalls.at(-1)?.ts || Trace.Types.Timing.Micro(10e5),
    samples: [],
    timeDeltas: [],
  };

  const nodesIds = new Map<number, Protocol.Profiler.ProfileNode>();
  const lastTimestamp = profile.startTime;
  for (const profileCall of profileCalls) {
    let node = nodesIds.get(profileCall.nodeId);
    if (!node) {
      node = {
        id: profileCall.nodeId,
        callFrame: profileCall.callFrame,
      };
      profile.nodes.push(node);
      nodesIds.set(profileCall.nodeId, node);
    }
    profile.samples?.push(node.id);
    const timeDelta = profileCall.ts - lastTimestamp;
    profile.timeDeltas?.push(timeDelta);
  }
  const profileData = {
    rawProfile: profile,
    parsedProfile: new CPUProfile.CPUProfileDataModel.CPUProfileDataModel(profile),
    profileCalls,
    profileTree: tree,
    profileId: Trace.Types.Events.ProfileID('fake-profile-id'),
  };
  const profilesInThread = new Map([[1 as Trace.Types.Events.ThreadID, profileData]]);
  return {
    profilesInProcess: new Map([[1 as Trace.Types.Events.ProcessID, profilesInThread]]),
    entryToNode,
  };
}

export function makeMockEntityData(events: Trace.Types.Events.Event[]): Trace.Handlers.Helpers.EntityMappings {
  const eventsByEntity = new Map<Trace.Handlers.Helpers.Entity, Trace.Types.Events.Event[]>();
  const entityByEvent = new Map<Trace.Types.Events.Event, Trace.Handlers.Helpers.Entity>();
  const createdEntityCache = new Map<string, Trace.Handlers.Helpers.Entity>();

  events.forEach(event => {
    const entity = Trace.Handlers.Helpers.getEntityForEvent(event, createdEntityCache);
    if (!entity) {
      return;
    }
    if (eventsByEntity.has(entity)) {
      const events = eventsByEntity.get(entity) ?? [];
      events?.push(event);
    } else {
      eventsByEntity.set(entity, [event]);
    }
    entityByEvent.set(event, entity);
  });
  return {eventsByEntity, entityByEvent, createdEntityCache};
}

export class FakeFlameChartProvider implements PerfUI.FlameChart.FlameChartDataProvider {
  minimumBoundary(): number {
    return 0;
  }

  hasTrackConfigurationMode(): boolean {
    return false;
  }

  totalTime(): number {
    return 100;
  }

  formatValue(value: number): string {
    return value.toString();
  }

  maxStackDepth(): number {
    return 3;
  }

  preparePopoverElement(_entryIndex: number): Element|null {
    return null;
  }

  canJumpToEntry(_entryIndex: number): boolean {
    return false;
  }

  entryTitle(entryIndex: number): string|null {
    return `Entry ${entryIndex}`;
  }

  entryFont(_entryIndex: number): string|null {
    return null;
  }

  entryColor(entryIndex: number): string {
    return [
      'lightblue',
      'lightpink',
      'yellow',
      'lightgray',
      'lightgreen',
      'lightsalmon',
      'orange',
      'pink',
    ][entryIndex % 8];
  }

  decorateEntry(): boolean {
    return false;
  }

  forceDecoration(_entryIndex: number): boolean {
    return false;
  }

  textColor(_entryIndex: number): string {
    return 'black';
  }

  timelineData(): PerfUI.FlameChart.FlameChartTimelineData|null {
    return PerfUI.FlameChart.FlameChartTimelineData.createEmpty();
  }
}

export function getMainThread(data: Trace.Handlers.ModelHandlers.Renderer.RendererHandlerData):
    Trace.Handlers.ModelHandlers.Renderer.RendererThread {
  let mainThread: Trace.Handlers.ModelHandlers.Renderer.RendererThread|null = null;
  for (const [, process] of data.processes) {
    for (const [, thread] of process.threads) {
      if (thread.name === 'CrRendererMain') {
        mainThread = thread;
        break;
      }
    }
  }
  if (!mainThread) {
    throw new Error('Could not find main thread.');
  }
  return mainThread;
}

type ParsedTrace = Trace.Handlers.Types.ParsedTrace;

export function getBaseTraceParseModelData(overrides: Partial<ParsedTrace> = {}): ParsedTrace {
  return {
    Animations: {animations: []},
    AnimationFrames: {
      animationFrames: [],
      presentationForFrame: new Map(),
    },
    DOMStats: {
      domStatsByFrameId: new Map(),
    },
    LayoutShifts: {
      clusters: [],
      clustersByNavigationId: new Map(),
      sessionMaxScore: 0,
      clsWindowID: 0,
      prePaintEvents: [],
      layoutInvalidationEvents: [],
      scheduleStyleInvalidationEvents: [],
      styleRecalcInvalidationEvents: [],
      renderFrameImplCreateChildFrameEvents: [],
      domLoadingEvents: [],
      layoutImageUnsizedEvents: [],
      beginRemoteFontLoadEvents: [],
      scoreRecords: [],
      backendNodeIds: [],
      paintImageEvents: [],
    },
    Meta: {
      traceBounds: {
        min: Trace.Types.Timing.Micro(0),
        max: Trace.Types.Timing.Micro(100),
        range: Trace.Types.Timing.Micro(100),
      },
      browserProcessId: Trace.Types.Events.ProcessID(-1),
      browserThreadId: Trace.Types.Events.ThreadID(-1),
      gpuProcessId: Trace.Types.Events.ProcessID(-1),
      gpuThreadId: Trace.Types.Events.ThreadID(-1),
      threadsInProcess: new Map(),
      navigationsByFrameId: new Map(),
      navigationsByNavigationId: new Map(),
      mainFrameId: '',
      mainFrameURL: '',
      rendererProcessesByFrame: new Map(),
      topLevelRendererIds: new Set(),
      frameByProcessId: new Map(),
      mainFrameNavigations: [],
      traceIsGeneric: false,
      processNames: new Map(),
    },
    Renderer: {
      processes: new Map(),
      compositorTileWorkers: new Map(),
      entryToNode: new Map(),
      allTraceEntries: [],
      entityMappings: {
        entityByEvent: new Map(),
        eventsByEntity: new Map(),
        createdEntityCache: new Map(),
      },
    },
    Screenshots: {
      legacySyntheticScreenshots: [],
      screenshots: [],
    },
    Samples: {
      entryToNode: new Map(),
      profilesInProcess: new Map(),
    },
    PageLoadMetrics: {metricScoresByFrameId: new Map(), allMarkerEvents: []},
    UserInteractions: {
      allEvents: [],
      interactionEvents: [],
      beginCommitCompositorFrameEvents: [],
      parseMetaViewportEvents: [],
      interactionEventsWithNoNesting: [],
      longestInteractionEvent: null,
      interactionsOverThreshold: new Set(),
    },
    NetworkRequests: {
      byId: new Map(),
      eventToInitiator: new Map(),
      byOrigin: new Map(),
      byTime: [],
      webSocket: [],
      entityMappings: {
        entityByEvent: new Map(),
        eventsByEntity: new Map(),
        createdEntityCache: new Map(),
      },
    },
    GPU: {
      mainGPUThreadTasks: [],
    },
    UserTimings: {
      consoleTimings: [],
      performanceMarks: [],
      performanceMeasures: [],
      timestampEvents: [],
      measureTraceByTraceId: new Map(),
    },
    LargestImagePaint: {lcpRequestByNavigation: new Map()},
    LargestTextPaint: new Map(),
    AuctionWorklets: {
      worklets: new Map(),
    },
    ExtensionTraceData: {
      entryToNode: new Map(),
      extensionMarkers: [],
      extensionTrackData: [],
      syntheticConsoleEntriesForTimingsTrack: [],
    },
    Frames: {
      frames: [],
      framesById: {},
    },
    ImagePainting: {
      paintImageByDrawLazyPixelRef: new Map(),
      paintImageForEvent: new Map(),
      paintImageEventForUrl: new Map(),
    },
    Initiators: {
      eventToInitiator: new Map(),
      initiatorToEvents: new Map(),
    },
    Invalidations: {
      invalidationCountForEvent: new Map(),
      invalidationsForEvent: new Map(),
    },
    LayerTree: {
      paints: [],
      paintsToSnapshots: new Map(),
      snapshots: [],
    },
    Memory: {
      updateCountersByProcess: new Map(),
    },
    PageFrames: {
      frames: new Map(),
    },
    SelectorStats: {
      dataForUpdateLayoutEvent: new Map(),
    },
    ServerTimings: {
      serverTimings: [],
    },
    Warnings: {
      perEvent: new Map(),
      perWarning: new Map(),
    },
    Workers: {
      workerIdByThread: new Map(),
      workerSessionIdEvents: [],
      workerURLById: new Map(),
    },
    Flows: {
      flows: [],
    },
    AsyncJSCalls: {
      schedulerToRunEntryPoints: new Map(),
      asyncCallToScheduler: new Map(),
    },
    ...overrides,
  };
}

/**
 * A helper that will query the given array of events and find the first event
 * matching the predicate. It will also assert that a match is found, which
 * saves the need to do that for every test.
 */
export function getEventOfType<T extends Trace.Types.Events.Event>(
    events: Trace.Types.Events.Event[], predicate: (e: Trace.Types.Events.Event) => e is T): T {
  const match = events.find(predicate);
  if (!match) {
    throw new Error('Failed to find matching event of type.');
  }
  return match;
}

/**
 * The Performance Panel is integrated with the IgnoreListManager so in tests
 * that render a flame chart or a track appender, it needs to be setup to avoid
 * errors.
 */
export function setupIgnoreListManagerEnvironment(): {
  ignoreListManager: Bindings.IgnoreListManager.IgnoreListManager,
} {
  const targetManager = SDK.TargetManager.TargetManager.instance({forceNew: true});
  const workspace = Workspace.Workspace.WorkspaceImpl.instance({forceNew: true});
  const resourceMapping = new Bindings.ResourceMapping.ResourceMapping(targetManager, workspace);

  const debuggerWorkspaceBinding = Bindings.DebuggerWorkspaceBinding.DebuggerWorkspaceBinding.instance({
    forceNew: true,
    resourceMapping,
    targetManager,
  });

  const ignoreListManager = Bindings.IgnoreListManager.IgnoreListManager.instance({
    forceNew: true,
    debuggerWorkspaceBinding,
  });

  return {ignoreListManager};
}

export function microsecondsTraceWindow(min: number, max: number): Trace.Types.Timing.TraceWindowMicro {
  return Trace.Helpers.Timing.traceWindowFromMicroSeconds(
      min as Trace.Types.Timing.Micro,
      max as Trace.Types.Timing.Micro,
  );
}

export function microseconds(x: number): Trace.Types.Timing.Micro {
  return Trace.Types.Timing.Micro(x);
}

export function milliseconds(x: number): Trace.Types.Timing.Milli {
  return Trace.Types.Timing.Milli(x);
}