Moving towards a complete npm package.

.gitignore

@@ -1,6 +1,7 @@
-*.json
-*.jsonp
-**
-!icon.png
-!README.md
-!zipcodes.js
+.env
+.DS_Store
+npm-debug.log
+node_modules/
+.build/
+yarn-error.log
+*.php

package.json

@@ -0,0 +1,22 @@
+{
+  "name": "zipcodes.js",
+  "version": "1.0.0",
+  "description": "Free postal code validation for the web.",
+  "main": "index.js",
+  "repository": "https://github.com/zipcodes/zipcodes.js",
+  "author": "Heath Dutton <heathdutton@gmail.com>",
+  "license": "GNU General Public License v3.0",
+  "scripts": {
+    "build": "rollup -c --environment INCLUDE_DEPS,BUILD:production"
+  },
+  "dependencies": {},
+  "devDependencies": {
+    "@babel/core": "^7.4.3",
+    "@babel/preset-env": "^7.4.3",
+    "jest": "^24.7.1",
+    "rollup": "^1.10.0",
+    "rollup-plugin-babel": "^4.3.2",
+    "rollup-plugin-babel-minify": "^8.0.0",
+    "rollup-plugin-node-resolve": "^4.2.3"
+  }
+}

rollup.config.js

@@ -0,0 +1,18 @@
+import babel from 'rollup-plugin-babel'
+import resolve from 'rollup-plugin-node-resolve'
+import minify from 'rollup-plugin-babel-minify'
+
+export default {
+  input: "src/index.js",
+  output: {
+    file: ".build/zipcode.min.js",
+    format: "cjs"
+  },
+  plugins: [
+    resolve(),
+    babel({
+      exclude: 'node_modules/**'
+    }),
+    minify()
+  ]
+}

src/.babelrc

@@ -0,0 +1,11 @@
+{
+  "presets": [
+    [
+      "@babel/env",
+      {
+        "modules": false,
+        "useBuiltIns": "usage"
+      }
+    ]
+  ]
+}

zipcodes.js → src/index.js

@@ -8,8 +8,8 @@
  *   });
  *
  */
-var getZipCode = function (country, zip, callback) {
-    var keys = {
+const getZipCode = (c, zip, callback) => {
+    let keys = {
             AD: 0,
             AR: 2,
             AS: 0,
@@ -138,21 +138,21 @@ var getZipCode = function (country, zip, callback) {
             'accuracy'
         ],
         pattern = null,
-        country = country && country.toLocaleUpperCase();
+        country = c && c.toLocaleUpperCase();
 
     // Check patterns.
     if (typeof patterns[country] !== 'undefined') {
         pattern = patterns[country];
     }
     else {
-        for (var k in patterns) {
+        for (let k in patterns) {
             if (patterns.hasOwnProperty(k) && k.indexOf(country) > 0) {
                 pattern = patterns[k];
                 break;
             }
         }
     }
-    var result = {
+    let result = {
         input: {
             country: country,
             zip: zip
@@ -173,15 +173,15 @@ var getZipCode = function (country, zip, callback) {
             }
             window.zipCodesCallback = function (zipCodes) {
                 if (typeof zipCodes[zip] !== 'undefined') {
-                    for (var i = 0, len = headers.length; i < len; i++) {
+                    for (let i = 0, len = headers.length; i < len; i++) {
                         result.lookup[headers[i]] = zipCodes[zip][i];
                     }
                     result.validLookup = true;
                     result.valid = true;
                 }
                 callback(result);
             };
-            var k = keys[country] > 0 ? zip.toUpperCase().replace(/[^0-9A-Z]/g, '').substr(0, keys[country]) : 0,
+            let k = keys[country] > 0 ? zip.toUpperCase().replace(/[^0-9A-Z]/g, '').substr(0, keys[country]) : 0,
                 script = document.createElement('script');
             script.src = 'https://' + country + '.zipcodes.gdn/min/' + k + '.jsonp';
             document.body.appendChild(script);
@@ -192,4 +192,6 @@ var getZipCode = function (country, zip, callback) {
             callback(result);
         }
     }
-};
+};
+
+module.exports = getZipCode