chore: fix lint errors and add lint to CI (#1689)

Fixes some leftover lint errors and adds lint to CI.

Author: 43081j

.github/workflows/node.js.yml

@@ -10,6 +10,17 @@ on:
     branches: [ main, 4.x.x ]
 
 jobs:
+  lint:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v4
+    - name: Use Node.js ${{ matrix.node-version }}
+      uses: actions/setup-node@v4
+      with:
+        node-version: 22
+    - run: npm ci
+    - run: npm run lint
+
   build:
 
     runs-on: ubuntu-latest

lib/chai/assertion.js

@@ -11,43 +11,43 @@ import * as util from './utils/index.js';
 
 export class Assertion {
   /** @type {{}} */
-  __flags = {}
-
-/**
- * Creates object for chaining.
- * `Assertion` objects contain metadata in the form of flags. Three flags can
- * be assigned during instantiation by passing arguments to this constructor:
- *
- * - `object`: This flag contains the target of the assertion. For example, in
- * the assertion `expect(numKittens).to.equal(7);`, the `object` flag will
- * contain `numKittens` so that the `equal` assertion can reference it when
- * needed.
- *
- * - `message`: This flag contains an optional custom error message to be
- * prepended to the error message that's generated by the assertion when it
- * fails.
- *
- * - `ssfi`: This flag stands for "start stack function indicator". It
- * contains a function reference that serves as the starting point for
- * removing frames from the stack trace of the error that's created by the
- * assertion when it fails. The goal is to provide a cleaner stack trace to
- * end users by removing Chai's internal functions. Note that it only works
- * in environments that support `Error.captureStackTrace`, and only when
- * `Chai.config.includeStack` hasn't been set to `false`.
- *
- * - `lockSsfi`: This flag controls whether or not the given `ssfi` flag
- * should retain its current value, even as assertions are chained off of
- * this object. This is usually set to `true` when creating a new assertion
- * from within another assertion. It's also temporarily set to `true` before
- * an overwritten assertion gets called by the overwriting assertion.
- *
- * - `eql`: This flag contains the deepEqual function to be used by the assertion.
- *
- * @param {unknown} obj target of the assertion
- * @param {string} [msg] (optional) custom error message
- * @param {Function} [ssfi] (optional) starting point for removing stack frames
- * @param {boolean} [lockSsfi] (optional) whether or not the ssfi flag is locked
- */
+  __flags = {};
+
+  /**
+   * Creates object for chaining.
+   * `Assertion` objects contain metadata in the form of flags. Three flags can
+   * be assigned during instantiation by passing arguments to this constructor:
+   *
+   * - `object`: This flag contains the target of the assertion. For example, in
+   * the assertion `expect(numKittens).to.equal(7);`, the `object` flag will
+   * contain `numKittens` so that the `equal` assertion can reference it when
+   * needed.
+   *
+   * - `message`: This flag contains an optional custom error message to be
+   * prepended to the error message that's generated by the assertion when it
+   * fails.
+   *
+   * - `ssfi`: This flag stands for "start stack function indicator". It
+   * contains a function reference that serves as the starting point for
+   * removing frames from the stack trace of the error that's created by the
+   * assertion when it fails. The goal is to provide a cleaner stack trace to
+   * end users by removing Chai's internal functions. Note that it only works
+   * in environments that support `Error.captureStackTrace`, and only when
+   * `Chai.config.includeStack` hasn't been set to `false`.
+   *
+   * - `lockSsfi`: This flag controls whether or not the given `ssfi` flag
+   * should retain its current value, even as assertions are chained off of
+   * this object. This is usually set to `true` when creating a new assertion
+   * from within another assertion. It's also temporarily set to `true` before
+   * an overwritten assertion gets called by the overwriting assertion.
+   *
+   * - `eql`: This flag contains the deepEqual function to be used by the assertion.
+   *
+   * @param {unknown} obj target of the assertion
+   * @param {string} [msg] (optional) custom error message
+   * @param {Function} [ssfi] (optional) starting point for removing stack frames
+   * @param {boolean} [lockSsfi] (optional) whether or not the ssfi flag is locked
+   */
   constructor(obj, msg, ssfi, lockSsfi) {
     util.flag(this, 'ssfi', ssfi || Assertion);
     util.flag(this, 'lockSsfi', lockSsfi);
@@ -155,22 +155,22 @@ export class Assertion {
    * @returns {void}
    */
   assert(_expr, msg, _negateMsg, expected, _actual, showDiff) {
-    var ok = util.test(this, arguments);
+    const ok = util.test(this, arguments);
     if (false !== showDiff) showDiff = true;
     if (undefined === expected && undefined === _actual) showDiff = false;
     if (true !== config.showDiff) showDiff = false;
 
     if (!ok) {
       msg = util.getMessage(this, arguments);
-      var actual = util.getActual(this, arguments);
+      const actual = util.getActual(this, arguments);
       /** @type {Record<PropertyKey, unknown>} */
-      var assertionErrorObjectProperties = {
+      const assertionErrorObjectProperties = {
         actual: actual,
         expected: expected,
         showDiff: showDiff
       };
 
-      var operator = util.getOperator(this, arguments);
+      const operator = util.getOperator(this, arguments);
       if (operator) {
         assertionErrorObjectProperties.operator = operator;
       }