Port 1578683 - Turn on ESLint rule prefer-boolean-length-check for toolkit and browser (#5313)

common/Reducers.jsm

@@ -307,7 +307,7 @@ function Sections(prevState = INITIAL_STATE.Sections, action) {
       });
       // Otherwise, append it
       if (!hasMatch) {
-        const initialized = !!(action.data.rows && action.data.rows.length > 0);
+        const initialized = !!(action.data.rows && !!action.data.rows.length);
         const section = Object.assign(
           { title: "", rows: [], enabled: false },
           action.data,
@@ -327,7 +327,7 @@ function Sections(prevState = INITIAL_STATE.Sections, action) {
           // Disabling a section (SECTION_UPDATE with empty rows) does not retain pinned cards.
           if (
             action.data.rows &&
-            action.data.rows.length > 0 &&
+            !!action.data.rows.length &&
             section.rows.find(card => card.pinned)
           ) {
             const rows = Array.from(action.data.rows);

content-src/asrouter/templates/StartupOverlay/StartupOverlay.jsx

@@ -82,7 +82,7 @@ export class StartupOverlay extends React.PureComponent {
    */
   _getFormInfo() {
     const value = {
-      has_flow_params: this.props.flowParams.flowId.length > 0,
+      has_flow_params: !!this.props.flowParams.flowId.length,
     };
     return { value };
   }

content-src/asrouter/templates/Trailhead/Trailhead.jsx

@@ -112,7 +112,7 @@ export class Trailhead extends React.PureComponent {
    * Report to telemetry additional information about the form submission.
    */
   _getFormInfo() {
-    const value = { has_flow_params: this.props.flowParams.flowId.length > 0 };
+    const value = { has_flow_params: !!this.props.flowParams.flowId.length };
     return { value };
   }
 

content-src/components/DiscoveryStreamBase/DiscoveryStreamBase.jsx

@@ -335,7 +335,7 @@ export class _DiscoveryStreamBase extends React.PureComponent {
               components: [topSites],
             },
           ])}
-        {layoutRender.length > 0 && (
+        {!!layoutRender.length && (
           <CollapsibleSection
             className="ds-layout"
             collapsed={topStories.pref.collapsed}

content-src/components/Sections/Sections.jsx

@@ -200,7 +200,7 @@ export class Section extends React.PureComponent {
     const isPocketLoggedInDefined =
       isUserLoggedIn === true || isUserLoggedIn === false;
 
-    const hasTopics = topics && topics.length > 0;
+    const hasTopics = topics && !!topics.length;
 
     const shouldShowPocketCta =
       id === "topstories" && useCta && isUserLoggedIn === false;

lib/ASRouterTargeting.jsm

@@ -96,7 +96,7 @@ function CheckBrowserNeedsUpdate(
         const now = Date.now();
         const updateServiceListener = {
           onCheckComplete(request, updates) {
-            checker._value = updates.length > 0;
+            checker._value = !!updates.length;
             resolve(checker._value);
           },
           onError(request, update) {

lib/CFRPageActions.jsm

@@ -257,7 +257,7 @@ class PageAction {
   }
 
   _clearScheduledStateChanges() {
-    while (this.stateTransitionTimeoutIDs.length > 0) {
+    while (this.stateTransitionTimeoutIDs.length) {
       // clearTimeout is safe even with invalid/expired IDs
       this.window.clearTimeout(this.stateTransitionTimeoutIDs.pop());
     }

lib/PlacesFeed.jsm

@@ -366,7 +366,7 @@ class PlacesFeed {
   _getSearchPrefix() {
     const searchAliases =
       Services.search.defaultEngine.wrappedJSObject.__internalAliases;
-    if (searchAliases && searchAliases.length > 0) {
+    if (searchAliases && searchAliases.length) {
       return `${searchAliases[0]} `;
     }
     return "";

lib/ShortURL.jsm

@@ -71,7 +71,7 @@ function shortURL({ url }) {
 
   // Remove the eTLD (e.g., com, net) and the preceding period from the hostname
   const eTLD = getETLD(hostname);
-  const eTLDExtra = eTLD.length > 0 ? -(eTLD.length + 1) : Infinity;
+  const eTLDExtra = eTLD.length ? -(eTLD.length + 1) : Infinity;
 
   // Ideally get the short eTLD-less host but fall back to longer url parts
   return (

lib/TopStoriesFeed.jsm

@@ -314,7 +314,7 @@ this.TopStoriesFeed = class TopStoriesFeed {
       );
       this.domainAffinitiesLastUpdated = affinities._timestamp;
     }
-    if (stories && stories.length > 0 && this.storiesLastUpdated === 0) {
+    if (stories && !!stories.length && this.storiesLastUpdated === 0) {
       this.updateSettings(data.stories.settings);
       this.stories = this.rotate(this.transform(stories));
       this.storiesLastUpdated = data.stories._timestamp;
@@ -328,7 +328,7 @@ this.TopStoriesFeed = class TopStoriesFeed {
         this.cleanUpCampaignImpressionPref();
       }
     }
-    if (topics && topics.length > 0 && this.topicsLastUpdated === 0) {
+    if (topics && !!topics.length && this.topicsLastUpdated === 0) {
       this.topics = topics;
       this.topicsLastUpdated = data.topics._timestamp;
     }

test/unit/asrouter/CFRMessageProvider.test.js

@@ -51,8 +51,8 @@ describe("CFRMessageProvider", () => {
     const pinTabMessage = messages.find(m => m.id === "PIN_TAB");
 
     assert.isTrue(
-      pinTabMessage.trigger.params.filter(host => host.startsWith("www."))
-        .length > 0
+      !!pinTabMessage.trigger.params.filter(host => host.startsWith("www."))
+        .length
     );
   });
 });

test/unit/content-src/components/TopSites.test.jsx

@@ -463,7 +463,7 @@ describe("<TopSiteLink>", () => {
   it("should have rtl direction automatically set for text", () => {
     const wrapper = shallow(<TopSiteLink link={link} />);
 
-    assert.isTrue(wrapper.find("[dir='auto']").length > 0);
+    assert.isTrue(!!wrapper.find("[dir='auto']").length);
   });
   it("should render a title", () => {
     const wrapper = shallow(<TopSiteLink link={link} title="foobar" />);