Modernize

index.js

@@ -1,30 +1,41 @@
 'use strict';
 
-module.exports = TokenStream;
-function TokenStream(tokens) {
-  if (!Array.isArray(tokens)) {
-    throw new TypeError('tokens must be passed to TokenStream as an array.');
+/** @template T */
+module.exports = class TokenStream {
+  #tokens
+
+  /** @param {T[]} tokens */
+  constructor (tokens) {
+    if (!Array.isArray(tokens)) {
+      throw new TypeError('tokens must be passed to TokenStream as an array.');
+    }
+    this.#tokens = tokens;
   }
-  this._tokens = tokens;
-}
-TokenStream.prototype.lookahead = function (index) {
-  if (this._tokens.length <= index) {
-    throw new Error('Cannot read past the end of a stream');
+
+  /** @param {number} index */
+  lookahead (index) {
+    if (this.#tokens.length <= index) {
+      throw new Error('Cannot read past the end of a stream');
+    }
+    return this.#tokens[index];
+  }
+
+  peek () {
+    if (this.#tokens.length === 0) {
+      throw new Error('Cannot read past the end of a stream');
+    }
+    return this.#tokens[0];
   }
-  return this._tokens[index];
-};
-TokenStream.prototype.peek = function () {
-  if (this._tokens.length === 0) {
-    throw new Error('Cannot read past the end of a stream');
+
+  advance () {
+    if (this.#tokens.length === 0) {
+      throw new Error('Cannot read past the end of a stream');
+    }
+    return this.#tokens.shift();
   }
-  return this._tokens[0];
-};
-TokenStream.prototype.advance = function () {
-  if (this._tokens.length === 0) {
-    throw new Error('Cannot read past the end of a stream');
+
+  /** @param {T} token */
+  defer (token) {
+    this.#tokens.unshift(token);
   }
-  return this._tokens.shift();
-};
-TokenStream.prototype.defer = function (token) {
-  this._tokens.unshift(token);
-};
+}

package.json

@@ -4,11 +4,11 @@
   "description": "Take an array of token and produce a more useful API to give to a parser",
   "dependencies": {},
   "devDependencies": {
-    "istanbul": "*"
+    "c8": "*"
   },
   "scripts": {
-    "test": "node test && npm run coverage",
-    "coverage": "istanbul cover test"
+    "test": "node test/index.js && npm run coverage",
+    "coverage": "c8 node test/index.js"
   },
   "repository": {
     "type": "git",

test/index.js

@@ -1,7 +1,7 @@
 'use strict';
 
 var assert = require('assert');
-var TokenStream = require('../');
+var TokenStream = require('../index.js');
 
 assert.throws(function () {
   new TokenStream('foo,bar');