core(tsc): remove more reliance on implicit index signatures

lighthouse-cli/bin.js

@@ -107,6 +107,7 @@ function run() {
       }
     })
     .then(_ => {
+      // @ts-ignore TODO(bckenny): Sentry type checking
       Sentry.init({
         url,
         flags: cliFlags,

lighthouse-core/audits/dobetterweb/dom-size.js

@@ -101,6 +101,7 @@ class DOMSize extends Audit {
       {key: 'width', itemType: 'text', text: str_(UIStrings.columnDOMWidth)},
     ];
 
+    /** @type {Array<Object<string, LH.Audit.DetailsItem>>} */
     const items = [
       {
         totalNodes: Util.formatNumber(stats.totalDOMNodes),

lighthouse-core/audits/user-timings.js

@@ -56,6 +56,7 @@ class UserTimings extends Audit {
   static filterTrace(tabTrace) {
     /** @type {Array<MarkEvent|MeasureEvent>} */
     const userTimings = [];
+    /** @type {Record<string, number>} */
     const measuresStartTimes = {};
 
     // Get all blink.user_timing events

lighthouse-core/gather/computed/metrics/lantern-metric.js

@@ -85,6 +85,7 @@ class LanternMetricArtifact extends ComputedArtifact {
     const optimisticGraph = this.getOptimisticGraph(graph, traceOfTab);
     const pessimisticGraph = this.getPessimisticGraph(graph, traceOfTab);
 
+    /** @type {{flexibleOrdering?: boolean, label?: string}} */
     let simulateOptions = {label: `optimistic${metricName}`};
     const optimisticSimulation = simulator.simulate(optimisticGraph, simulateOptions);
 

lighthouse-core/lib/dependency-graph/simulator/network-analyzer.js

@@ -11,8 +11,11 @@ const NetworkRequest = require('../../network-request');
 // Assume that 40% of TTFB was server response time by default for static assets
 const DEFAULT_SERVER_RESPONSE_PERCENTAGE = 0.4;
 
-// For certain resource types, server response time takes up a greater percentage of TTFB (dynamic
-// assets like HTML documents, XHR/API calls, etc)
+/**
+ * For certain resource types, server response time takes up a greater percentage of TTFB (dynamic
+ * assets like HTML documents, XHR/API calls, etc)
+ * @type {Partial<Record<LH.Crdp.Page.ResourceType, number>>}
+ */
 const SERVER_RESPONSE_PERCENTAGE_OF_TTFB = {
   Document: 0.9,
   XHR: 0.9,
@@ -73,9 +76,11 @@ class NetworkAnalyzer {
     return summaryByKey;
   }
 
+  /** @typedef {{record: LH.Artifacts.NetworkRequest, timing: LH.Crdp.Network.ResourceTiming, connectionReused?: boolean}} RequestInfo */
+
   /**
    * @param {LH.Artifacts.NetworkRequest[]} records
-   * @param {function(any):any} iteratee
+   * @param {(e: RequestInfo) => number | number[] | undefined} iteratee
    * @return {Map<string, number[]>}
    */
   static _estimateValueByOrigin(records, iteratee) {
@@ -190,6 +195,7 @@ class NetworkAnalyzer {
   static _estimateRTTByOriginViaHeadersEndTiming(records) {
     return NetworkAnalyzer._estimateValueByOrigin(records, ({record, timing, connectionReused}) => {
       if (!Number.isFinite(timing.receiveHeadersEnd) || timing.receiveHeadersEnd < 0) return;
+      if (!record.resourceType) return;
 
       const serverResponseTimePercentage = SERVER_RESPONSE_PERCENTAGE_OF_TTFB[record.resourceType]
         || DEFAULT_SERVER_RESPONSE_PERCENTAGE;

lighthouse-core/lib/i18n.js

@@ -175,6 +175,7 @@ function _formatPathAsString(pathInLHR) {
  */
 function getRendererFormattedStrings(locale) {
   const icuMessageIds = Object.keys(LOCALES[locale]).filter(f => f.includes('core/report/html/'));
+  /** @type {LH.I18NRendererStrings} */
   const strings = {};
   for (const icuMessageId of icuMessageIds) {
     const [filename, varName] = icuMessageId.split(' | ');
@@ -190,6 +191,7 @@ function getRendererFormattedStrings(locale) {
  * @param {Record<string, string>} fileStrings
  */
 function createMessageInstanceIdFn(filename, fileStrings) {
+  /** @type {Record<string, string>} */
   const mergedStrings = {...UIStrings, ...fileStrings};
 
   /** @param {string} icuMessage @param {*} [values] */
@@ -284,6 +286,7 @@ function replaceIcuMessageInstanceIds(lhr, locale) {
     }
   }
 
+  /** @type {LH.I18NMessages} */
   const icuMessagePaths = {};
   replaceInObject(lhr, icuMessagePaths);
   return icuMessagePaths;

lighthouse-core/report/html/renderer/report-ui-features.js

@@ -90,7 +90,7 @@ class ReportUIFeatures {
     this._setupHeaderAnimation();
     this._resetUIState();
     this._document.addEventListener('keydown', this.printShortCutDetect);
-    // @ts-ignore - tsc thinks document can't listen for `copy`
+    // @ts-ignore - TODO(bckenny): tsc thinks document can't listen for `copy`. Remove ignore in 3.1.
     this._document.addEventListener('copy', this.onCopy);
   }
 
@@ -447,6 +447,7 @@ class ReportUIFeatures {
    */
   getReportHtml() {
     this._resetUIState();
+    // @ts-ignore - technically documentElement can be null, but that's dumb - https://dom.spec.whatwg.org/#document-element
     return this._document.documentElement.outerHTML;
   }
 

lighthouse-core/report/html/renderer/util.js

@@ -223,6 +223,7 @@ class Util {
    * @return {string}
    */
   static formatDateTime(date) {
+    /** @type {Intl.DateTimeFormatOptions} */
     const options = {
       month: 'short', day: 'numeric', year: 'numeric',
       hour: 'numeric', minute: 'numeric', timeZoneName: 'short',
@@ -444,6 +445,10 @@ class Util {
  */
 Util.numberDateLocale = 'en';
 
+/**
+ * Report-renderer-specific strings.
+ * @type {LH.I18NRendererStrings}
+ */
 Util.UIStrings = {
   /** Disclaimer shown to users below the metric values (First Contentful Paint, Time to Interactive, etc) to warn them that the numbers they see will likely change slightly the next time they run Lighthouse. */
   varianceDisclaimer: 'Values are estimated and may vary.',

lighthouse-core/runner.js

@@ -368,6 +368,7 @@ class Runner {
       const ArtifactClass = require('./gather/computed/' + filename);
       const artifact = new ArtifactClass(computedArtifacts);
       // define the request* function that will be exposed on `artifacts`
+      // @ts-ignore - doesn't have an index signature, so can't be set dynamically.
       computedArtifacts['request' + artifact.name] = artifact.request.bind(artifact);
     });
 

lighthouse-core/scoring.js

@@ -50,6 +50,7 @@ class ReportScoring {
    * @return {Object<string, LH.Result.Category>}
    */
   static scoreAllCategories(configCategories, resultsByAuditId) {
+    /** @type {Record<string, LH.Result.Category>} */
     const scoredCategories = {};
 
     for (const [categoryId, configCategory] of Object.entries(configCategories)) {

lighthouse-core/scripts/i18n/collect-strings.js

@@ -103,6 +103,7 @@ function collectAllStringsInDir(dir, strings = {}) {
  */
 function writeStringsToLocaleFormat(locale, strings) {
   const fullPath = path.join(LH_ROOT, `lighthouse-core/lib/locales/${locale}.json`);
+  /** @type {Record<string, ICUMessageDefn>} */
   const output = {};
   const sortedEntries = Object.entries(strings).sort(([keyA], [keyB]) => keyA.localeCompare(keyB));
   for (const [key, defn] of sortedEntries) {

lighthouse-extension/app/src/lighthouse-ext-background.js

@@ -122,7 +122,9 @@ function createReportPageAsBlob(reportHtml) {
  */
 function saveSettings(settings) {
   const storage = {
+    /** @type {Record<string, boolean>} */
     [STORAGE_KEY]: {},
+    /** @type {Record<string, boolean>} */
     [SETTINGS_KEY]: {},
   };
 
@@ -149,6 +151,7 @@ function loadSettings() {
     chrome.storage.local.get([STORAGE_KEY, SETTINGS_KEY], result => {
       // Start with list of all default categories set to true so list is
       // always up to date.
+      /** @type {Record<string, boolean>} */
       const defaultCategories = {};
       background.getDefaultCategories().forEach(category => {
         defaultCategories[category.id] = true;