chore: add test for loading via AMD

.karma.config.js

@@ -3,10 +3,11 @@ module.exports = function (config) {
     frameworks: ['mocha', 'chai'],
     files: [
       'slug.js',
-      'test/**/*.js'
+      'node_modules/requirejs/require.js', // Used to test loading via AMD.
+      'test/**/*.js',
     ],
     preprocessors: { 'slug.js': 'coverage' },
-    reporters: ['coverage'],
+    reporters: ['progress', 'coverage'],
     coverageReporter: {
       dir: '.nyc_output',
       reporters: [

package.json

@@ -32,6 +32,7 @@
         "karma-mocha": "^2.0.1",
         "mocha": "^7.0.0",
         "nyc": "^15.0.1",
+        "requirejs": "^2.3.6",
         "standard": "^14.3.3"
     },
     "licenses": [

test/slug.test.js

@@ -1,7 +1,9 @@
 /* global beforeEach, chai, describe, it */
 
+const inBrowser = typeof window !== 'undefined'
+
 describe('slug', function () {
-  const slug = (typeof window !== 'undefined' && window.slug) || require('../slug')
+  const slug = (inBrowser && window.slug) || require('../slug')
   const assert = typeof chai === 'undefined' ? require('assert') : chai.assert
 
   beforeEach(slug.reset)
@@ -959,4 +961,21 @@ describe('slug', function () {
   it('should handle a lone high surrogate by itself', () => {
     assert.strictEqual(slug(String.fromCodePoint(55296)), 'ia')
   })
+
+  it('should be able to be loaded via amd', (done) => {
+    const modulePath = inBrowser ? 'base/slug' : '../slug'
+    const requirejs = (inBrowser && window.requirejs) || require('requirejs')
+
+    if (!inBrowser) {
+      requirejs.config({
+        nodeRequire: require
+      })
+    }
+
+    requirejs([modulePath], function (amdSlug) {
+      // Use toString() to compare source code.
+      assert.deepStrictEqual(amdSlug.toString(), slug.toString())
+      done()
+    })
+  })
 })