Enforce usage of type-safe equality operators

Using == / != is a source of bugs.

Rule doc page: https://eslint.org/docs/latest/rules/eqeqeq

.eslintrc.yaml

@@ -17,6 +17,7 @@ ignorePatterns:
 
 rules:
   # Code quality rules
+  eqeqeq: error
   no-unused-vars: error
   no-use-before-define: ["error", { "functions": false, "classes": false }]
   prefer-const: ["error", {"destructuring": "all"}]

src/authz/index.js

@@ -18,9 +18,9 @@ import tags from './tags.js';
  */
 function authorized(user, action, object) {
   // user may be null
-  assert(!user || user.authzRoles != null, "user.authzRoles is not null if user is not null");
+  assert(!user || user.authzRoles !== null, "user.authzRoles is not null if user is not null");
   assert(actions.has(action), "action is known");
-  assert(object != null, "object is not null");
+  assert(object !== null, "object is not null");
 
   /* As a safe guard, anonymous users can only ever read, regardless of
    * policies right now.  We don't have any use cases right now where letting

src/sources/groups.js

@@ -112,7 +112,7 @@ class GroupSource extends Source {
     let {title, byline, website, showDatasets, showNarratives} = frontMatter;
 
     // Must be an allowed protocol
-    if (website != null) {
+    if (website !== null) {
       const {protocol} = parseUrl(website) ?? {};
       const allowedProtocols = new Set(["https:", "http:", "ftp:", "ftps:", "mailto:"]);
       if (!allowedProtocols.has(protocol)) {

src/upstream.js

@@ -346,7 +346,7 @@ function copyHeaders(headerSource, headerNames) {
   return Object.fromEntries(
     headerNames
       .map(name => [name, headerSource.get(name)])
-      .filter(([name, value]) => value != null && value !== "") // eslint-disable-line no-unused-vars
+      .filter(([name, value]) => value !== null && value !== "") // eslint-disable-line no-unused-vars
   );
 }
 

src/utils/index.js

@@ -109,7 +109,7 @@ const parseNarrativeLanguage = (narrative) => {
 const normalizeHeaders = (headers) => {
   const withValues =
     Object.entries(headers)
-      .filter(([, value]) => value != null && value !== "");
+      .filter(([, value]) => value !== null && value !== "");
 
   /* Use the WHATWG Headers object to do most of the normalization, including
    * lowercasing and combining duplicate headers as appropriate.

src/utils/scripts.js

@@ -91,7 +91,7 @@ async function run(argv) {
     proc.stderr.on("data", data => console.error(data.toString().replace(/\n$/, "")));
 
     proc.on("close", (code, signal) => {
-      const result = code !== 0 || signal != null
+      const result = code !== 0 || signal !== null
         ? reject
         : resolve;
       return result({code, signal, argv});

static-site/src/components/ExpandableTiles/index.tsx

@@ -31,7 +31,7 @@ export const ExpandableTiles = <AnyTile extends Tile>({tiles, tileWidth, tileHei
   function tilesContainerRef(tilesContainer: HTMLDivElement) {
     if (!tilesContainer) return;
 
-    if(tilesContainerHeight != tilesContainer.clientHeight) {
+    if(tilesContainerHeight !== tilesContainer.clientHeight) {
       setTilesContainerHeight(tilesContainer.clientHeight)
     }
   }

static-site/src/components/ListResources/IndividualResource.tsx

@@ -130,7 +130,7 @@ export const IndividualResource = ({resource, isMobile}: IndividualResourceProps
     // don't do anything if the ref is undefined or the parent is not a div (IndividualResourceContainer)
     if (!ref.current
      || !ref.current.parentNode
-     || ref.current.parentNode.nodeName != 'DIV') return;
+     || ref.current.parentNode.nodeName !== 'DIV') return;
 
     /* The column CSS is great but doesn't allow us to know if an element is at
     the top of its column, so we resort to JS */

static-site/src/components/nav-bar/index.tsx

@@ -119,7 +119,7 @@ const NavBar = ({ minified }: {
 
   return (
     <NavContainer>
-      {Router.pathname != "/" && <>
+      {Router.pathname !== "/" && <>
         <Logo />
         <LogoType />
       </>}