From a9f19588ce7b4265d8b3f540cc83c601ac284bd5 Mon Sep 17 00:00:00 2001
From: Sukka <isukkaw@gmail.com>
Date: Thu, 6 Aug 2020 13:14:58 +0800
Subject: [PATCH] refactor: use Object.assign & Map (#36)

---
 lib/pagination.js | 25 ++++++++++++++-----------
 1 file changed, 14 insertions(+), 11 deletions(-)

diff --git a/lib/pagination.js b/lib/pagination.js
index 7217427..8d6f07a 100644
--- a/lib/pagination.js
+++ b/lib/pagination.js
@@ -6,23 +6,26 @@ function pagination(base, posts, options = {}) {
   if (typeof base !== 'string') throw new TypeError('base must be a string!');
   if (!posts) throw new TypeError('posts is required!');
 
-  if (base && base[base.length - 1] !== '/') base += '/';
+  if (base && !base.endsWith('/')) base += '/';
+
+  const { length } = posts;
+
+  const { format: _format, layout, data, perPage } = Object.assign({
+    format: 'page/%d/',
+    layout: ['archive', 'index'],
+    data: {},
+    perPage: 10
+  }, options);
 
-  const length = posts.length;
-  const perPage = Object.prototype.hasOwnProperty.call(options, 'perPage') ? +options.perPage : 10;
   const total = perPage ? Math.ceil(length / perPage) : 1;
-  const _format = options.format || 'page/%d/';
-  const layout = options.layout || ['archive', 'index'];
-  const data = options.data || {};
   const result = [];
-  const urlCache = {};
+  const urlCache = new Map();
 
   function formatURL(i) {
-    if (urlCache[i]) return urlCache[i];
+    if (urlCache.has(i)) return urlCache.get(i);
 
-    let url = base;
-    if (i > 1) url += format(_format, i);
-    urlCache[i] = url;
+    const url = i > 1 ? base + format(_format, i) : base;
+    urlCache.set(i, url);
 
     return url;
   }