add rule to prefer includes over indexof plus linting

Author: zorkow

eslint.config.mjs

@@ -19,6 +19,7 @@ export default tseslint.config({
   files: ['ts/**/*.ts'],
   ignores: ["**/*.d.ts", "**/*.js", "**/cjs/*"],
   "rules": {
+    "@typescript-eslint/prefer-includes": "error",
     "@typescript-eslint/no-explicit-any": "off",
     "@typescript-eslint/no-unused-vars": ["error",
                                           { "varsIgnorePattern": "^_", "argsIgnorePattern": "^_",

ts/a11y/explorer/KeyExplorer.ts

@@ -494,7 +494,7 @@ export class SpeechExplorer
         );
         while (internal && internal !== this.generators.element) {
           const sid = internal.getAttribute('data-semantic-id');
-          if (dummies.indexOf(sid) !== -1) {
+          if (dummies.includes(sid)) {
             this.current = this.node.querySelector(
               `[data-semantic-id="${sid}"]`
             );

ts/adaptors/HTMLAdaptor.ts

@@ -514,7 +514,7 @@ export class HTMLAdaptor<
     if (node.classList) {
       return node.classList.contains(name);
     }
-    return node.className.split(/ /).indexOf(name) >= 0;
+    return node.className.split(/ /).includes(name);
   }
 
   /**

ts/components/package.ts

@@ -230,7 +230,7 @@ export class Package {
     //
     for (const dependent of dependencies) {
       const extension = map.get(dependent) || new Package(dependent, noLoad);
-      if (this.dependencies.indexOf(extension) < 0) {
+      if (!this.dependencies.includes(extension)) {
         extension.addDependent(this, noLoad);
         this.dependencies.push(extension);
         if (!extension.isLoaded) {

ts/input/tex/Configuration.ts

@@ -436,7 +436,7 @@ export class ParserConfiguration {
    */
   protected getPackage(name: string): Configuration {
     const config = ConfigurationHandler.get(name);
-    if (config && this.parsers.indexOf(config.parser) < 0) {
+    if (config && !this.parsers.includes(config.parser)) {
       throw Error(`Package ${name} doesn't target the proper parser`);
     }
     return config;

ts/input/tex/ParseUtil.ts

@@ -80,7 +80,7 @@ export const KeyValueTypes: {
   oneof: (...values: string[]) =>
     new KeyValueType<string>(
       'oneof',
-      (value) => values.indexOf(value) >= 0,
+      (value) => values.includes(value),
       (value) => value
     ),
   dimen: new KeyValueType<string>(
@@ -191,7 +191,7 @@ function readValue(
         countBraces = false; // Stop counting start left braces.
         break;
       default:
-        if (!braces && end.indexOf(c) !== -1) {
+        if (!braces && end.includes(c)) {
           // End character reached.
           return [
             removeBraces(value, l3keys ? Math.min(1, start) : start),

ts/input/tex/bussproofs/BussproofsMethods.ts

@@ -144,7 +144,7 @@ function parseFCenterLine(parser: TexParser, name: string): MmlNode {
   }
   parser.i++;
   const axiom = parser.GetUpTo(name, '$');
-  if (axiom.indexOf('\\fCenter') === -1) {
+  if (!axiom.includes('\\fCenter')) {
     throw new TexError(
       'MissingProofCommand',
       'Missing %1 in %2.',

ts/input/tex/physics/PhysicsMethods.ts

@@ -137,7 +137,7 @@ function vectorApplication(
   let lfence = '',
     rfence = '',
     arg = '';
-  const enlarge = fences.indexOf(left) !== -1;
+  const enlarge = fences.includes(left);
   if (left === '{') {
     arg = parser.GetArgument(name);
     lfence = enlarge ? '\\left\\{' : '';

ts/input/tex/require/RequireConfiguration.ts

@@ -56,7 +56,7 @@ function RegisterExtension(jax: TeX<any, any, any>, name: string) {
   const required = jax.parseOptions.packageData.get('require')
     .required as string[];
   const extension = name.substring(require.prefix.length);
-  if (required.indexOf(extension) < 0) {
+  if (!required.includes(extension)) {
     required.push(extension);
     //
     //  Register any dependencies that were loaded to handle this one,

ts/output/common/Wrappers/mtable.ts

@@ -1085,7 +1085,7 @@ export function CommonMtableMixin<
      * @override
      */
     public getColumnWidthsPercent(swidths: string[]): ColumnWidths {
-      const hasFit = swidths.indexOf('fit') >= 0;
+      const hasFit = swidths.includes('fit');
       const { W } = hasFit ? this.getTableData() : { W: null };
       return Array.from(swidths.keys()).map((i) => {
         const x = swidths[i];