use const and let (#57)

README.md

@@ -1,6 +1,6 @@
 # brace-expansion
 
-[Brace expansion](https://www.gnu.org/software/bash/manual/html_node/Brace-Expansion.html), 
+[Brace expansion](https://www.gnu.org/software/bash/manual/html_node/Brace-Expansion.html),
 as known from sh/bash, in JavaScript.
 
 [![CI](https://github.com/juliangruber/brace-expansion/actions/workflows/ci.yml/badge.svg)](https://github.com/juliangruber/brace-expansion/actions/workflows/ci.yml)
@@ -9,7 +9,7 @@ as known from sh/bash, in JavaScript.
 ## Example
 
 ```js
-var expand = require('brace-expansion');
+const expand = require('brace-expansion');
 
 expand('file-{a,b,c}.jpg')
 // => ['file-a.jpg', 'file-b.jpg', 'file-c.jpg']
@@ -45,10 +45,10 @@ expand('ppp{,config,oe{,conf}}')
 ## API
 
 ```js
-var expand = require('brace-expansion');
+const expand = require('brace-expansion');
 ```
 
-### var expanded = expand(str)
+### const expanded = expand(str)
 
 Return an array of all possible and valid expansions of `str`. If none are
 found, `[str]` is returned.

example.js

@@ -1,4 +1,4 @@
-var expand = require('./');
+const expand = require('./');
 
 console.log(expand('http://any.org/archive{1996..1999}/vol{1..4}/part{a,b,c}.html'));
 console.log(expand('http://www.numericals.com/file{1..100..10}.txt'));

index.js

@@ -1,12 +1,10 @@
-var balanced = require('balanced-match');
+const balanced = require('balanced-match');
 
-module.exports = expandTop;
-
-var escSlash = '\0SLASH'+Math.random()+'\0';
-var escOpen = '\0OPEN'+Math.random()+'\0';
-var escClose = '\0CLOSE'+Math.random()+'\0';
-var escComma = '\0COMMA'+Math.random()+'\0';
-var escPeriod = '\0PERIOD'+Math.random()+'\0';
+const escSlash = '\0SLASH'+Math.random()+'\0';
+const escOpen = '\0OPEN'+Math.random()+'\0';
+const escClose = '\0CLOSE'+Math.random()+'\0';
+const escComma = '\0COMMA'+Math.random()+'\0';
+const escPeriod = '\0PERIOD'+Math.random()+'\0';
 
 /**
  * @return {number}
@@ -49,19 +47,17 @@ function parseCommaParts(str) {
  if (!str)
  return [''];
 
- var parts = [];
- var m = balanced('{', '}', str);
+ const parts = [];
+ const m = balanced('{', '}', str);
 
  if (!m)
  return str.split(',');
 
- var pre = m.pre;
- var body = m.body;
- var post = m.post;
- var p = pre.split(',');
+ const {pre, body, post} = m;
+ const p = pre.split(',');
 
  p[p.length-1] += '{' + body + '}';
- var postParts = parseCommaParts(post);
+ const postParts = parseCommaParts(post);
  if (post.length) {
  p[p.length-1] += postParts.shift();
  p.push.apply(p, postParts);
@@ -85,8 +81,8 @@ function expandTop(str) {
  // but a{},b}c will be expanded to [a}c,abc].
  // One could argue that this is a bug in Bash, but since the goal of
  // this module is to match Bash's rules, we escape a leading {}
- if (str.substr(0, 2) === '{}') {
- str = '\\{\\}' + str.substr(2);
+ if (str.slice(0, 2) === '{}') {
+ str = '\\{\\}' + str.slice(2);
  }
 
  return expand(escapeBraces(str), true).map(unescapeBraces);
@@ -98,6 +94,7 @@ function expandTop(str) {
 function embrace(str) {
  return '{' + str + '}';
 }
+
 /**
  * @param {string} el
  */
@@ -112,6 +109,7 @@ function isPadded(el) {
 function lte(i, y) {
  return i <= y;
 }
+
 /**
  * @param {number} i
  * @param {number} y
@@ -126,27 +124,27 @@ function gte(i, y) {
  */
 function expand(str, isTop) {
  /** @type {string[]} */
- var expansions = [];
+ const expansions = [];
 
- var m = balanced('{', '}', str);
+ const m = balanced('{', '}', str);
  if (!m) return [str];
 
  // no need to expand pre, since it is guaranteed to be free of brace-sets
- var pre = m.pre;
- var post = m.post.length
+ const pre = m.pre;
+ const post = m.post.length
  ? expand(m.post, false)
  : [''];
 
  if (/\$$/.test(m.pre)) {
- for (var k = 0; k < post.length; k++) {
- var expansion = pre+ '{' + m.body + '}' + post[k];
+ for (let k = 0; k < post.length; k++) {
+ const expansion = pre+ '{' + m.body + '}' + post[k];
  expansions.push(expansion);
  }
  } else {
- var isNumericSequence = /^-?\d+\.\.-?\d+(?:\.\.-?\d+)?$/.test(m.body);
- var isAlphaSequence = /^[a-zA-Z]\.\.[a-zA-Z](?:\.\.-?\d+)?$/.test(m.body);
- var isSequence = isNumericSequence || isAlphaSequence;
- var isOptions = m.body.indexOf(',') >= 0;
+ const isNumericSequence = /^-?\d+\.\.-?\d+(?:\.\.-?\d+)?$/.test(m.body);
+ const isAlphaSequence = /^[a-zA-Z]\.\.[a-zA-Z](?:\.\.-?\d+)?$/.test(m.body);
+ const isSequence = isNumericSequence || isAlphaSequence;
+ const isOptions = m.body.indexOf(',') >= 0;
  if (!isSequence && !isOptions) {
  // {a},b}
  if (m.post.match(/,.*\}/)) {
@@ -156,7 +154,7 @@ function expand(str, isTop) {
  return [str];
  }
 
- var n;
+ let n;
  if (isSequence) {
  n = m.body.split(/\.\./);
  } else {
@@ -174,37 +172,37 @@ function expand(str, isTop) {
 
  // at this point, n is the parts, and we know it's not a comma set
  // with a single entry.
- var N;
+ let N;
 
  if (isSequence) {
- var x = numeric(n[0]);
- var y = numeric(n[1]);
- var width = Math.max(n[0].length, n[1].length)
- var incr = n.length == 3
+ const x = numeric(n[0]);
+ const y = numeric(n[1]);
+ const width = Math.max(n[0].length, n[1].length)
+ let incr = n.length == 3
  ? Math.abs(numeric(n[2]))
  : 1;
- var test = lte;
- var reverse = y < x;
+ let test = lte;
+ const reverse = y < x;
  if (reverse) {
  incr *= -1;
  test = gte;
  }
- var pad = n.some(isPadded);
+ const pad = n.some(isPadded);
 
  N = [];
 
- for (var i = x; test(i, y); i += incr) {
- var c;
+ for (let i = x; test(i, y); i += incr) {
+ let c;
  if (isAlphaSequence) {
  c = String.fromCharCode(i);
  if (c === '\\')
  c = '';
  } else {
  c = String(i);
  if (pad) {
- var need = width - c.length;
+ const need = width - c.length;
  if (need > 0) {
- var z = new Array(need + 1).join('0');
+ const z = new Array(need + 1).join('0');
  if (i < 0)
  c = '-' + z + c.slice(1);
  else
@@ -217,14 +215,14 @@ function expand(str, isTop) {
  } else {
  N = [];
 
- for (var j = 0; j < n.length; j++) {
+ for (let j = 0; j < n.length; j++) {
  N.push.apply(N, expand(n[j], false));
  }
  }
 
- for (var j = 0; j < N.length; j++) {
- for (var k = 0; k < post.length; k++) {
- var expansion = pre + N[j] + post[k];
+ for (let j = 0; j < N.length; j++) {
+ for (let k = 0; k < post.length; k++) {
+ const expansion = pre + N[j] + post[k];
  if (!isTop || isSequence || expansion)
  expansions.push(expansion);
  }
@@ -234,3 +232,4 @@ function expand(str, isTop) {
  return expansions;
 }
 
+module.exports = expandTop;

test/bash-comparison.js

@@ -1,17 +1,17 @@
-var test = require('tape');
-var expand = require('..');
-var fs = require('fs');
-var resfile = __dirname + '/bash-results.txt';
-var cases = fs.readFileSync(resfile, 'utf8').split('><><><><');
+const test = require('tape');
+const expand = require('..');
+const fs = require('fs');
+const resfile = __dirname + '/bash-results.txt';
+const cases = fs.readFileSync(resfile, 'utf8').split('><><><><');
 
 // throw away the EOF marker
 cases.pop()
 
 test('matches bash expansions', function(t) {
  cases.forEach(function(testcase) {
- var set = testcase.split('\n');
- var pattern = set.shift();
- var actual = expand(pattern);
+ let set = testcase.split('\n');
+ const pattern = set.shift();
+ const actual = expand(pattern);
 
  // If it expands to the empty string, then it's actually
  // just nothing, but Bash is a singly typed language, so

test/dollar.js

@@ -1,5 +1,5 @@
-var test = require('tape');
-var expand = require('..');
+const test = require('tape');
+const expand = require('..');
 
 test('ignores ${', function(t) {
  t.deepEqual(expand('${1..3}'), ['${1..3}']);

test/empty-option.js

@@ -1,5 +1,5 @@
-var test = require('tape');
-var expand = require('..');
+const test = require('tape');
+const expand = require('..');
 
 test('empty option', function(t) {
  t.deepEqual(expand('-v{,,,,}'), [

test/negative-increment.js

@@ -1,5 +1,5 @@
-var test = require('tape');
-var expand = require('..');
+const test = require('tape');
+const expand = require('..');
 
 test('negative increment', function(t) {
  t.deepEqual(expand('{3..1}'), ['3', '2', '1']);

test/nested.js

@@ -1,5 +1,5 @@
-var test = require('tape');
-var expand = require('..');
+const test = require('tape');
+const expand = require('..');
 
 test('nested', function(t) {
  t.deepEqual(expand('{a,b{1..3},c}'), [

test/order.js

@@ -1,5 +1,5 @@
-var test = require('tape');
-var expand = require('..');
+const test = require('tape');
+const expand = require('..');
 
 test('order', function(t) {
  t.deepEqual(expand('a{d,c,b}e'), [

test/pad.js

@@ -1,5 +1,5 @@
-var test = require('tape');
-var expand = require('..');
+const test = require('tape');
+const expand = require('..');
 
 test('pad', function(t) {
  t.deepEqual(expand('{9..11}'), [

test/perf/bench.js

@@ -1,8 +1,8 @@
 'use strict';
-var expand = require('../../');
-var fs = require('fs');
-var resfile = __dirname + '/../cases.txt';
-var cases = fs.readFileSync(resfile, 'utf8').split('\n');
+const expand = require('../../');
+const fs = require('fs');
+const resfile = __dirname + '/../cases.txt';
+const cases = fs.readFileSync(resfile, 'utf8').split('\n');
 
 bench('Average', function() {
  cases.forEach(function(testcase) {

test/same-type.js

@@ -1,5 +1,5 @@
-var test = require('tape');
-var expand = require('..');
+const test = require('tape');
+const expand = require('..');
 
 test('x and y of same type', function(t) {
  t.deepEqual(expand('{a..9}'), ['{a..9}']);

test/sequence.js

@@ -1,5 +1,5 @@
-var test = require('tape');
-var expand = require('..');
+const test = require('tape');
+const expand = require('..');
 
 test('numeric sequences', function(t) {
  t.deepEqual(expand('a{1..2}b{2..3}c'), [