refactor: switch to eslint flat config (#121)

* refactor: switch to eslint flat config

* remove .eslintignore

Makefile.js

@@ -4,9 +4,7 @@
  * @copyright jQuery Foundation and other contributors, https://jquery.org/
  * MIT License
  */
-/* global echo, exec, exit, set, target */
 
-/* eslint no-console: 0*/
 //------------------------------------------------------------------------------
 // Requirements
 //------------------------------------------------------------------------------
@@ -40,15 +38,12 @@ const NODE = "node",
 
  // Utilities - intentional extra space at the end of each string
  MOCHA = `${NODE_MODULES}/mocha/bin/_mocha `,
- ESLINT = `${NODE} ${NODE_MODULES}/eslint/bin/eslint `,
 
  // If switching back to Istanbul when may be working with ESM
  // ISTANBUL = `${NODE} ${NODE_MODULES}/istanbul/lib/cli.js `,
  C8 = `${NODE} ${NODE_MODULES}/c8/bin/c8.js`,
 
  // Files
- MAKEFILE = "./Makefile.js",
- JS_FILES = "lib/**/*.js",
  TEST_FILES = "tests/*.js",
  CJS_TEST_FILES = "tests/*.cjs";
 
@@ -60,39 +55,6 @@ target.all = function() {
  target.test();
 };
 
-target.lint = function() {
- let errors = 0,
- lastReturn;
-
- echo("Validating Makefile.js");
- lastReturn = exec(ESLINT + MAKEFILE);
- if (lastReturn.code !== 0) {
- errors++;
- }
-
- echo("Validating JavaScript files");
- lastReturn = exec(ESLINT + JS_FILES);
- if (lastReturn.code !== 0) {
- errors++;
- }
-
- echo("Validating JavaScript test files");
- lastReturn = exec(ESLINT + TEST_FILES);
- if (lastReturn.code !== 0) {
- errors++;
- }
-
- echo("Validating CJS JavaScript test files");
- lastReturn = exec(ESLINT + CJS_TEST_FILES);
- if (lastReturn.code !== 0) {
- errors++;
- }
-
- if (errors) {
- exit(1);
- }
-};
-
 target.test = function() {
  let errors = 0;
  let lastReturn = exec(`${NODE} ${MOCHA} -- -R progress -c ${CJS_TEST_FILES}`);

eslint.config.js

@@ -0,0 +1,46 @@
+import eslintConfigESLint from "eslint-config-eslint";
+import globals from "globals";
+import eslintPluginChaiFriendly from "eslint-plugin-chai-friendly";
+
+export default [
+ {
+ ignores: [
+ "dist/",
+ "coverage/"
+ ]
+ },
+ ...eslintConfigESLint,
+ {
+ files: ["lib/**"],
+ rules: {
+ "no-underscore-dangle": "off"
+ }
+ },
+ {
+ files: ["tests/**"],
+ ignores: ["tests/util/**"],
+ languageOptions: {
+ globals: {
+ ...globals.mocha
+ }
+ },
+ plugins: {
+ "chai-friendly": eslintPluginChaiFriendly
+ },
+ rules: {
+ "no-unused-expressions": "off",
+ "chai-friendly/no-unused-expressions": "error"
+ }
+ },
+ {
+ files: ["Makefile.js"],
+ languageOptions: {
+ globals: {
+ ...globals.shelljs
+ }
+ },
+ rules: {
+ "no-console": "off"
+ }
+ }
+];

lib/index.js

@@ -45,7 +45,6 @@
  * The main interface is the {@link analyze} function.
  * @module escope
  */
-/* eslint no-underscore-dangle: ["error", { "allow": ["__currentScope"] }] */
 
 import assert from "assert";
 

lib/pattern-visitor.js

@@ -22,8 +22,6 @@
  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
 
-/* eslint-disable no-undefined */
-
 import estraverse from "estraverse";
 import esrecurse from "esrecurse";
 
@@ -38,6 +36,9 @@ function getLast(xs) {
  return xs[xs.length - 1] || null;
 }
 
+/**
+ * Visitor for destructuring patterns.
+ */
 class PatternVisitor extends esrecurse.Visitor {
  static isPattern(node) {
  const nodeType = node.type;
@@ -66,7 +67,7 @@ class PatternVisitor extends esrecurse.Visitor {
 
  this.callback(pattern, {
  topLevel: pattern === this.rootPattern,
- rest: lastRestElement !== null && lastRestElement !== undefined && lastRestElement.argument === pattern,
+ rest: lastRestElement !== null && lastRestElement !== void 0 && lastRestElement.argument === pattern,
  assignments: this.assignments
  });
  }

lib/referencer.js

@@ -22,9 +22,6 @@
  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
 
-/* eslint-disable no-underscore-dangle */
-/* eslint-disable no-undefined */
-
 import estraverse from "estraverse";
 import esrecurse from "esrecurse";
 import Reference from "./reference.js";
@@ -51,7 +48,7 @@ function traverseIdentifierInPattern(options, rootPattern, referencer, callback)
  visitor.visit(rootPattern);
 
  // Process the right hand nodes recursively.
- if (referencer !== null && referencer !== undefined) {
+ if (referencer !== null && referencer !== void 0) {
  visitor.rightHandNodes.forEach(referencer.visit, referencer);
  }
 }
@@ -62,6 +59,9 @@ function traverseIdentifierInPattern(options, rootPattern, referencer, callback)
 // FIXME: Now, we don't create module environment, because the context is
 // implementation dependent.
 
+/**
+ * Visitor for import specifiers.
+ */
 class Importer extends esrecurse.Visitor {
  constructor(declaration, referencer) {
  super(null, referencer.options);
@@ -108,7 +108,9 @@ class Importer extends esrecurse.Visitor {
  }
 }
 
-// Referencing variables and creating bindings.
+/**
+ * Referencing variables and creating bindings.
+ */
 class Referencer extends esrecurse.Visitor {
  constructor(options, scopeManager) {
  super(null, options);
@@ -432,7 +434,7 @@ class Referencer extends esrecurse.Visitor {
  this.currentScope().__referencing(node);
  }
 
- // eslint-disable-next-line class-methods-use-this
+ // eslint-disable-next-line class-methods-use-this -- Desired as instance method
  PrivateIdentifier() {
 
  // Do nothing.
@@ -482,9 +484,9 @@ class Referencer extends esrecurse.Visitor {
  this.visitProperty(node);
  }
 
- BreakStatement() {} // eslint-disable-line class-methods-use-this
+ BreakStatement() {} // eslint-disable-line class-methods-use-this -- Desired as instance method
 
- ContinueStatement() {} // eslint-disable-line class-methods-use-this
+ ContinueStatement() {} // eslint-disable-line class-methods-use-this -- Desired as instance method
 
  LabeledStatement(node) {
  this.visit(node.body);
@@ -643,7 +645,7 @@ class Referencer extends esrecurse.Visitor {
  this.visit(local);
  }
 
- MetaProperty() { // eslint-disable-line class-methods-use-this
+ MetaProperty() { // eslint-disable-line class-methods-use-this -- Desired as instance method
 
  // do nothing.
  }

lib/scope-manager.js

@@ -22,8 +22,6 @@
  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
 
-/* eslint-disable no-underscore-dangle */
-
 import {
  BlockScope,
  CatchScope,
@@ -180,9 +178,9 @@ class ScopeManager {
  return null;
  }
 
- attach() { } // eslint-disable-line class-methods-use-this
+ attach() { } // eslint-disable-line class-methods-use-this -- Desired as instance method
 
- detach() { } // eslint-disable-line class-methods-use-this
+ detach() { } // eslint-disable-line class-methods-use-this -- Desired as instance method
 
  __nestScope(scope) {
  if (scope instanceof GlobalScope) {