Breaking: Switch to ESM

Also adds eslint-plugin-jsdoc for linter

.editorconfig

@@ -0,0 +1,15 @@
+; EditorConfig file: https://EditorConfig.org
+; Install the "EditorConfig" plugin into your editor to use
+
+root = true
+
+[*]
+charset = utf-8
+end_of_line = lf
+insert_final_newline = true
+indent_style = space
+indent_size = 4
+trim_trailing_whitespace = true
+
+[package.json]
+indent_size = 2

.eslintrc.cjs

@@ -0,0 +1,25 @@
+"use strict";
+
+module.exports = {
+    root: true,
+    extends: [
+        "eslint",
+        "plugin:node/recommended-module"
+    ],
+    parserOptions: {
+        sourceType: "module",
+        ecmaVersion: "2020"
+    },
+    overrides: [
+        {
+            files: ".eslintrc.js",
+            extends: ["eslint", "plugin:node/recommended-script"]
+        },
+        {
+            files: ["tests/**/*"],
+            env: {
+                mocha: true
+            }
+        }
+    ]
+};

.gitignore

@@ -8,3 +8,4 @@ npm-debug.log
 /.vscode
 .sublimelinterrc
 .eslint-release-info.json
+dist

Makefile.js

@@ -6,17 +6,20 @@
  */
 /* global echo, exec, exit, set, target */
 
-"use strict";
-
 /* eslint no-console: 0*/
 //------------------------------------------------------------------------------
 // Requirements
 //------------------------------------------------------------------------------
 
-require("shelljs/make");
-set("+e");
+import path from "path";
+import { fileURLToPath } from "url";
+
+import "shelljs/make.js";
+import checker from "npm-license";
 
-const checker = require("npm-license");
+const dirname = path.dirname(fileURLToPath(import.meta.url));
+
+set("+e");
 
 //------------------------------------------------------------------------------
 // Settings
@@ -31,12 +34,15 @@ const OPEN_SOURCE_LICENSES = [
 //------------------------------------------------------------------------------
 
 const NODE = "node",
-    NODE_MODULES = "./node_modules/",
+    NODE_MODULES = "./node_modules",
 
     // Utilities - intentional extra space at the end of each string
-    MOCHA = `${NODE_MODULES}mocha/bin/_mocha `,
+    MOCHA = `${NODE_MODULES}/mocha/bin/_mocha `,
     ESLINT = `${NODE} ${NODE_MODULES}/eslint/bin/eslint `,
-    ISTANBUL = `${NODE} ${NODE_MODULES}/istanbul/lib/cli.js `,
+
+    // If switching back to Istanbul when may be working with ESM
+    // ISTANBUL = `${NODE} ${NODE_MODULES}/istanbul/lib/cli.js `,
+    C8 = `${NODE} ${NODE_MODULES}/c8/bin/c8.js`,
 
     // Files
     MAKEFILE = "./Makefile.js",
@@ -80,7 +86,7 @@ target.lint = function() {
 
 target.test = function() {
     let errors = 0;
-    const lastReturn = exec(`${ISTANBUL} cover ${MOCHA} -- -R progress -c ${TEST_FILES}`);
+    const lastReturn = exec(`${C8} ${MOCHA} -- -R progress -c ${TEST_FILES}`);
 
     if (lastReturn.code !== 0) {
         errors++;
@@ -116,7 +122,7 @@ target.checkLicenses = function() {
     echo("Validating licenses");
 
     checker.init({
-        start: __dirname
+        start: dirname
     }, deps => {
         const impermissible = Object.keys(deps).map(dependency => ({
             name: dependency,

README.md

@@ -2,35 +2,47 @@
 
 ESLint Scope is the [ECMAScript](http://www.ecma-international.org/publications/standards/Ecma-262.htm) scope analyzer used in ESLint. It is a fork of [escope](http://github.com/estools/escope).
 
-## Usage
-
-Install:
+## Install
 
 ```
 npm i eslint-scope --save
 ```
 
+## 📖 Usage
+
+To use in an ESM file:
+
+```js
+import eslintScope from 'eslint-scope';
+```
+
+To use in a CommonJS file:
+
+```js
+const eslintScope = require('eslint-scope');
+```
+
 Example:
 
 ```js
-var eslintScope = require('eslint-scope');
-var espree = require('espree');
-var estraverse = require('estraverse');
+import eslintScope from 'eslint-scope';
+import espree from 'espree';
+import estraverse from 'estraverse';
 
-var ast = espree.parse(code, { range: true });
-var scopeManager = eslintScope.analyze(ast);
+const ast = espree.parse(code, { range: true });
+const scopeManager = eslintScope.analyze(ast);
 
-var currentScope = scopeManager.acquire(ast);   // global scope
+const currentScope = scopeManager.acquire(ast);   // global scope
 
 estraverse.traverse(ast, {
-    enter: function(node, parent) {
+    enter (node, parent) {
         // do stuff
 
         if (/Function/.test(node.type)) {
             currentScope = scopeManager.acquire(node);  // get current function scope
         }
     },
-    leave: function(node, parent) {
+    leave (node, parent) {
         if (/Function/.test(node.type)) {
             currentScope = currentScope.upper;  // set to parent scope
         }

lib/definition.js

@@ -21,9 +21,8 @@
   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
   THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
-"use strict";
 
-const Variable = require("./variable");
+import Variable from "./variable.js";
 
 /**
  * @constructor Definition
@@ -78,7 +77,7 @@ class ParameterDefinition extends Definition {
     }
 }
 
-module.exports = {
+export {
     ParameterDefinition,
     Definition
 };

lib/index.js

@@ -45,18 +45,19 @@
  * The main interface is the {@link analyze} function.
  * @module escope
  */
-"use strict";
-
 /* eslint no-underscore-dangle: ["error", { "allow": ["__currentScope"] }] */
 
-const assert = require("assert");
+import { readFileSync } from "fs";
+import assert from "assert";
+
+import ScopeManager from "./scope-manager.js";
+import Referencer from "./referencer.js";
+import Reference from "./reference.js";
+import Variable from "./variable.js";
 
-const ScopeManager = require("./scope-manager");
-const Referencer = require("./referencer");
-const Reference = require("./reference");
-const Variable = require("./variable");
-const Scope = require("./scope").Scope;
-const version = require("../package.json").version;
+const { version } = JSON.parse(
+    readFileSync(new URL("../package.json", import.meta.url))
+);
 
 /**
  * Set the default options
@@ -142,7 +143,7 @@ function analyze(tree, providedOptions) {
     return scopeManager;
 }
 
-module.exports = {
+export {
 
     /** @name module:escope.version */
     version,
@@ -153,13 +154,13 @@ module.exports = {
     /** @name module:escope.Variable */
     Variable,
 
-    /** @name module:escope.Scope */
-    Scope,
-
     /** @name module:escope.ScopeManager */
     ScopeManager,
     analyze
 };
 
+/** @name module:escope.Scope */
+export * from "./scope.js";
+
 
 /* vim: set sw=4 ts=4 et tw=80 : */

lib/pattern-visitor.js

@@ -21,12 +21,11 @@
   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
   THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
-"use strict";
 
 /* eslint-disable no-undefined */
 
-const Syntax = require("estraverse").Syntax;
-const esrecurse = require("esrecurse");
+import { Syntax } from "estraverse";
+import esrecurse from "esrecurse";
 
 /**
  * Get last array element
@@ -147,6 +146,6 @@ class PatternVisitor extends esrecurse.Visitor {
     }
 }
 
-module.exports = PatternVisitor;
+export default PatternVisitor;
 
 /* vim: set sw=4 ts=4 et tw=80 : */

lib/reference.js

@@ -21,7 +21,6 @@
   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
   THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
-"use strict";
 
 const READ = 0x1;
 const WRITE = 0x2;
@@ -162,6 +161,6 @@ Reference.WRITE = WRITE;
  */
 Reference.RW = RW;
 
-module.exports = Reference;
+export default Reference;
 
 /* vim: set sw=4 ts=4 et tw=80 : */

lib/referencer.js

@@ -21,21 +21,17 @@
   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
   THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
-"use strict";
 
 /* eslint-disable no-underscore-dangle */
 /* eslint-disable no-undefined */
 
-const Syntax = require("estraverse").Syntax;
-const esrecurse = require("esrecurse");
-const Reference = require("./reference");
-const Variable = require("./variable");
-const PatternVisitor = require("./pattern-visitor");
-const definition = require("./definition");
-const assert = require("assert");
-
-const ParameterDefinition = definition.ParameterDefinition;
-const Definition = definition.Definition;
+import { Syntax } from "estraverse";
+import esrecurse from "esrecurse";
+import Reference from "./reference.js";
+import Variable from "./variable.js";
+import PatternVisitor from "./pattern-visitor.js";
+import { Definition, ParameterDefinition } from "./definition.js";
+import assert from "assert";
 
 /**
  * Traverse identifier in pattern
@@ -624,6 +620,6 @@ class Referencer extends esrecurse.Visitor {
     }
 }
 
-module.exports = Referencer;
+export default Referencer;
 
 /* vim: set sw=4 ts=4 et tw=80 : */

lib/scope-manager.js

@@ -21,23 +21,22 @@
   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
   THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
-"use strict";
 
 /* eslint-disable no-underscore-dangle */
 
-const Scope = require("./scope");
-const assert = require("assert");
-
-const GlobalScope = Scope.GlobalScope;
-const CatchScope = Scope.CatchScope;
-const WithScope = Scope.WithScope;
-const ModuleScope = Scope.ModuleScope;
-const ClassScope = Scope.ClassScope;
-const SwitchScope = Scope.SwitchScope;
-const FunctionScope = Scope.FunctionScope;
-const ForScope = Scope.ForScope;
-const FunctionExpressionNameScope = Scope.FunctionExpressionNameScope;
-const BlockScope = Scope.BlockScope;
+import {
+    GlobalScope,
+    CatchScope,
+    WithScope,
+    ModuleScope,
+    ClassScope,
+    SwitchScope,
+    FunctionScope,
+    ForScope,
+    FunctionExpressionNameScope,
+    BlockScope
+} from "./scope.js";
+import assert from "assert";
 
 /**
  * @constructor ScopeManager
@@ -241,6 +240,6 @@ class ScopeManager {
     }
 }
 
-module.exports = ScopeManager;
+export default ScopeManager;
 
 /* vim: set sw=4 ts=4 et tw=80 : */