Frontend: fix all ESLint findings and add CI enforcement

.github/workflows/eslint.js.yml

@@ -0,0 +1,37 @@
+name: ESLint
+
+on:
+  push:
+    paths:
+      - 'frontend/**/*.ts'
+  pull_request:
+    branches:
+      - main
+
+defaults:
+  run:
+    working-directory: frontend
+
+jobs:
+  eslint:
+
+    runs-on: ubuntu-24.04
+
+    strategy:
+      matrix:
+        node-version: [24.x]
+
+    steps:
+    - uses: actions/checkout@v4
+    - name: Enable Corepack
+      run: corepack enable
+    - name: Use Node.js ${{ matrix.node-version }}
+      uses: actions/setup-node@v4
+      with:
+        node-version: ${{ matrix.node-version }}
+        cache: 'pnpm'
+        cache-dependency-path: 'frontend/pnpm-lock.yaml'
+    - name: Install dependencies
+      run: pnpm install --frozen-lockfile
+    - name: Run ESLint
+      run: pnpm run eslint

frontend/eslint.config.js

@@ -1,9 +1,17 @@
 import tsPlugin from '@typescript-eslint/eslint-plugin';
 import tsParser from '@typescript-eslint/parser';
 import jsdocPlugin from 'eslint-plugin-jsdoc';
+import chaiFriendlyPlugin from 'eslint-plugin-chai-friendly';
 
 export default [
-  jsdocPlugin.configs['flat/recommended'],
+  {
+    // tests/html/ is regenerated Sphinx build output (gitignored), not project code.
+    ignores: ['tests/html/**'],
+  },
+  {
+    ...jsdocPlugin.configs['flat/recommended'],
+    files: ['src/**/*.ts', 'tests/**/*.ts'],
+  },
   {
     files: ['src/**/*.ts', 'tests/**/*.ts'],
     plugins: {
@@ -21,6 +29,18 @@ export default [
       ...tsPlugin.configs.recommended.rules,
       'jsdoc/no-undefined-types': 'off',
       'max-len': ['error', {ignoreRegExpLiterals: true}],
+      '@typescript-eslint/no-unused-vars': ['error', {argsIgnorePattern: '^_'}],
+    },
+  },
+  {
+    // chai-friendly's rule recognizes chai assertions as non-dead expressions.
+    files: ['tests/**/*.ts'],
+    plugins: {
+      'chai-friendly': chaiFriendlyPlugin,
+    },
+    rules: {
+      '@typescript-eslint/no-unused-expressions': 'off',
+      'chai-friendly/no-unused-expressions': 'error',
     },
   },
 ];

frontend/package.json

@@ -43,6 +43,7 @@
     "css-loader": "^7.1.4",
     "css-minimizer-webpack-plugin": "^8.0.0",
     "eslint": "^10.7.0",
+    "eslint-plugin-chai-friendly": "^1.2.1",
     "eslint-plugin-jsdoc": "^63.2.0",
     "eslint-webpack-plugin": "^6.0.0",
     "file-loader": "^6.2.0",

frontend/src/ts/resource.ts

@@ -1,7 +1,5 @@
 /**
  * Corresponds to a text file
- *
- * @export
  */
 export type Resource = {
   basename: string;
@@ -10,7 +8,5 @@ export type Resource = {
 
 /**
  * Corresponds to a list of Resources
- *
- * @export
  */
 export type ResourceList = Array<Resource>;

frontend/tests/ts/areas.spec.ts

@@ -2,7 +2,7 @@
 import { expect, use } from 'chai';
 import chaiDom from 'chai-dom';
 
-const chai = use(chaiDom);
+use(chaiDom);
 
 // Import package under test
 import {Area, OutputArea, LabArea, makeLabArea, LabContainer}

frontend/tests/ts/dom-utils.spec.ts

@@ -1,7 +1,7 @@
 // Import testing libs
 import { expect, use } from 'chai';
 import chaiDom from 'chai-dom';
-const chai = use(chaiDom);
+use(chaiDom);
 
 import {getElemById, getElemsByClass, getElemsByTag}
   from '../../src/ts/dom-utils';

frontend/tests/ts/download.spec.ts

@@ -1,8 +1,7 @@
 import { expect, use } from 'chai';
 import chaiDom from 'chai-dom';
-import chaiAsPromised from 'chai-as-promised';
 
-const chai = use(chaiDom);
+use(chaiDom);
 
 import JSZip from 'jszip';
 import FileSaver from 'file-saver';
@@ -112,7 +111,8 @@ describe('Download', () => {
     });
 
     it('should find builder switches', () => {
-      const parsedSwitches = parseSwitches({Builder: ["test1", "test2"], Compiler: []});
+      const parsedSwitches = parseSwitches(
+          {Builder: ["test1", "test2"], Compiler: []});
       const expectedBuilder = 'for Switches ("Ada") use ("test1", "test2");';
       const expectedCompiler = 'for Switches ("Ada") use ();';
       expect(parsedSwitches['--BUILDER_SWITCHES_PLACEHOLDER--']).to.equal(
@@ -124,7 +124,8 @@ describe('Download', () => {
     });
 
     it('should find compiler switches', () => {
-      const parsedSwitches = parseSwitches({Builder: [], "Compiler": ["test3", "test4"]});
+      const parsedSwitches = parseSwitches(
+          {Builder: [], "Compiler": ["test3", "test4"]});
       const expectedBuilder = 'for Switches ("Ada") use ();';
       const expectedCompiler = 'for Switches ("Ada") use ("test3", "test4");';
       expect(parsedSwitches['--BUILDER_SWITCHES_PLACEHOLDER--']).to.equal(
@@ -213,7 +214,11 @@ describe('Download', () => {
     });
 
     it('should find a main (c file)', () => {
-      const cFile = `#include <stdio.h>\nint main() {\nprintf("Hello, World!");\nreturn 0;\n}`;
+      const cFile = `#include <stdio.h>
+int main() {
+printf("Hello, World!");
+return 0;
+}`;
       const files: ResourceList = [
         {basename: 'other.c', contents: cFile},
         {basename: 'test.ads', contents: ''},
@@ -259,13 +264,15 @@ describe('Download', () => {
   describe('#getGprContents()', () => {
     it('should replace all placeholders', () => {
       const files: ResourceList = [{basename: 'main.adb', contents: ''}];
-      const gpr = getGprContents(files, {Builder: [], Compiler: []}, 'main.adb', false);
+      const gpr =
+          getGprContents(files, {Builder: [], Compiler: []}, 'main.adb', false);
       expect(gpr).to.not.contain('--MAIN_PLACEHOLDER--');
       expect(gpr).to.not.contain('--LANGUAGE_PLACEHOLDER--');
       expect(gpr).to.not.contain('--COMPILER_SWITCHES_PLACEHOLDER--');
       expect(gpr).to.not.contain('--BUILDER_SWITCHES_PLACEHOLDER--');
       expect(gpr).to.not.contain('--');
-      const gpr_spark = getGprContents(files, {Builder: [], Compiler: []}, 'main.adb', true);
+      const gpr_spark =
+          getGprContents(files, {Builder: [], Compiler: []}, 'main.adb', true);
       expect(gpr_spark).to.not.contain('--MAIN_PLACEHOLDER--');
       expect(gpr_spark).to.not.contain('--LANGUAGE_PLACEHOLDER--');
       expect(gpr_spark).to.not.contain('--COMPILER_SWITCHES_PLACEHOLDER--');
@@ -281,7 +288,8 @@ describe('Download', () => {
     let origGenerateAsync: any;
 
     const files: ResourceList = [
-      {basename: 'main.adb', contents: 'procedure Main is begin null; end Main;'},
+      {basename: 'main.adb',
+        contents: 'procedure Main is begin null; end Main;'},
     ];
     const switches: UnparsedSwitches = {Builder: [], Compiler: []};
 
@@ -299,6 +307,7 @@ describe('Download', () => {
     });
 
     after(() => {
+      // eslint-disable-next-line @typescript-eslint/no-explicit-any
       (JSZip.prototype as any).generateAsync = origGenerateAsync;
     });
 
@@ -313,7 +322,8 @@ describe('Download', () => {
       expect(savedFilename).to.equal('MyProject.zip');
     });
 
-    it('should include source, main.gpr, and main.adc in non-SPARK mode', async () => {
+    it('should include source, main.gpr, and main.adc in non-SPARK mode',
+        async () => {
       downloadProject(files, switches, 'main.adb', 'Test', false);
       await new Promise((r) => setTimeout(r, 200));
       expect(capturedFileNames).to.include('main.adb');
@@ -323,7 +333,8 @@ describe('Download', () => {
       expect(capturedFileNames).not.to.include('main_spark.adc');
     });
 
-    it('should also include main_spark.gpr and main_spark.adc in SPARK mode', async () => {
+    it('should also include main_spark.gpr and main_spark.adc in SPARK mode',
+        async () => {
       downloadProject(files, switches, 'main.adb', 'Test', true);
       await new Promise((r) => setTimeout(r, 200));
       expect(capturedFileNames).to.include('main.gpr');

frontend/tests/ts/editor.spec.ts

@@ -2,7 +2,7 @@
 import { expect, use } from 'chai';
 import chaiDom from 'chai-dom';
 
-const chai = use(chaiDom);
+use(chaiDom);
 
 import * as Ace from 'ace-builds';
 
@@ -40,7 +40,8 @@ describe('Editor', () => {
     });
 
     it('should set C_CPP mode for a .c file', () => {
-      const cResource: Resource = {basename: 'main.c', contents: 'int main() { return 0; }'};
+      const cResource: Resource =
+          {basename: 'main.c', contents: 'int main() { return 0; }'};
       inTest.addSession(cResource.basename, cResource.contents);
       inTest.setSession(cResource.basename);
       const session = editor.getSession();

frontend/tests/ts/scrolltop.spec.ts

@@ -2,13 +2,12 @@
 import { expect, use } from 'chai';
 import chaiDom from 'chai-dom';
 
-const chai = use(chaiDom);
+use(chaiDom);
 
 import {scrollTop} from '../../src/ts/scrolltop';
 
 /**
  * Helper function to trigger window event
- *
  * @param {Window} element - The window element
  * @param {string} eventName - The event to do
  */
@@ -20,9 +19,8 @@ function triggerEvent(element: Window, eventName: string): void {
 
 /**
  * Helper function used to override default non implemented version in JSDOM
- *
- * @param {number} x
- * @param {number} y
+ * @param {number} x - The x-coordinate to scroll to
+ * @param {number} y - The y-coordinate to scroll to
  */
 function scrollTo(x: number, y: number): void {
   document.body.scrollTop = y;

frontend/tests/ts/server.spec.ts

@@ -4,7 +4,7 @@ import chaiAsPromised from 'chai-as-promised';
 import chaiDom from 'chai-dom';
 
 use(chaiAsPromised);
-const chai = use(chaiDom);
+use(chaiDom);
 
 import {Server, WebSocket} from 'mock-socket';
 
@@ -14,10 +14,9 @@ import {CheckOutput, RunProgram} from '../../src/ts/server-types';
 global.WebSocket = WebSocket as unknown as typeof globalThis.WebSocket;
 
 /**
-* Remove all event listeners from the server
-*
-* @param {Server} server - The server to remove the listeners from
-*/
+ * Remove all event listeners from the server
+ * @param {Server} server - The server to remove the listeners from
+ */
 function removeListeners(server: Server): void {
  for (let type in server.listeners) {
    server.listeners[type] = [];
@@ -36,7 +35,8 @@ describe('ServerWorker', () => {
     lab: false,
   };
   let server: Server = new Server(baseURL);
-  let client: ServerWorker = new ServerWorker(baseURL, (data: CheckOutput.FS): boolean => {
+  let client: ServerWorker = new ServerWorker(baseURL,
+      (data: CheckOutput.FS): boolean => {
     cbCount++;
     return data.completed;
   });
@@ -66,7 +66,7 @@ describe('ServerWorker', () => {
 
     before(() => {
       server.on('connection', (socket) => {
-        socket.on('message', (event) => {
+        socket.on('message', (_event) => {
           serverResponses.forEach((msg) => {
             socket.send(JSON.stringify(msg));
           });
@@ -95,7 +95,7 @@ describe('ServerWorker', () => {
 
     before(() => {
       server.on('connection', (socket) => {
-        socket.on('message', (event) => {
+        socket.on('message', (_event) => {
           socket.send(JSON.stringify(serverResponse));
         });
       });
@@ -106,7 +106,8 @@ describe('ServerWorker', () => {
     });
 
     it('should throw an exception when AWS rejects the request', async () => {
-      await expect(client.execute(tsData, 2000)).to.be.rejectedWith(expectedErrorMsg);
+      await expect(client.execute(tsData, 2000))
+          .to.be.rejectedWith(expectedErrorMsg);
     });
   });
 
@@ -117,7 +118,7 @@ describe('ServerWorker', () => {
 
     before(() => {
       server.on('connection', (socket) => {
-        socket.on('message', (event) => {});
+        socket.on('message', (_event) => {});
       });
     });
 
@@ -126,7 +127,8 @@ describe('ServerWorker', () => {
     });
 
     it('should timeout if no response is recieved', async () => {
-      await expect(client.execute(tsData, timeout)).to.be.rejectedWith(expectedErrorMsg);
+      await expect(client.execute(tsData, timeout))
+          .to.be.rejectedWith(expectedErrorMsg);
     });
   });
 });