rewrite unit tests for selector engine

js/src/dom/selector-engine.js

@@ -22,37 +22,22 @@ const SelectorEngine = {
   },
 
   find(selector, element = document.documentElement) {
-    if (typeof selector !== 'string') {
-      return null
-    }
-
     return findFn.call(element, selector)
   },
 
   findOne(selector, element = document.documentElement) {
-    if (typeof selector !== 'string') {
-      return null
-    }
-
     return findOne.call(element, selector)
   },
 
   children(element, selector) {
-    if (typeof selector !== 'string') {
-      return null
-    }
-
     const children = makeArray(element.children)
 
     return children.filter(child => this.matches(child, selector))
   },
 
   parents(element, selector) {
-    if (typeof selector !== 'string') {
-      return null
-    }
-
     const parents = []
+
     let ancestor = element.parentNode
 
     while (ancestor && ancestor.nodeType === Node.ELEMENT_NODE && ancestor.nodeType !== NODE_TEXT) {
@@ -67,19 +52,12 @@ const SelectorEngine = {
   },
 
   closest(element, selector) {
-    if (typeof selector !== 'string') {
-      return null
-    }
-
     return closest.call(element, selector)
   },
 
   prev(element, selector) {
-    if (typeof selector !== 'string') {
-      return null
-    }
-
     const siblings = []
+
     let previous = element.previousSibling
 
     while (previous && previous.nodeType === Node.ELEMENT_NODE && previous.nodeType !== NODE_TEXT) {

js/src/dom/selector-engine.spec.js

@@ -0,0 +1,115 @@
+import SelectorEngine from './selector-engine'
+import { makeArray } from '../util/index'
+
+/** Test helpers */
+import { getFixture, clearFixture } from '../../tests/helpers/fixture'
+
+describe('SelectorEngine', () => {
+  let fixtureEl
+
+  beforeAll(() => {
+    fixtureEl = getFixture()
+  })
+
+  afterEach(() => {
+    clearFixture()
+  })
+
+  describe('matches', () => {
+    it('should return matched elements', () => {
+      fixtureEl.innerHTML = '<div></div>'
+
+      expect(SelectorEngine.matches(fixtureEl, 'div')).toEqual(true)
+    })
+  })
+
+  describe('find', () => {
+    it('should find elements', () => {
+      fixtureEl.innerHTML = '<div></div>'
+
+      const div = fixtureEl.querySelector('div')
+
+      expect(makeArray(SelectorEngine.find('div', fixtureEl))).toEqual([div])
+    })
+
+    it('should find elements globaly', () => {
+      fixtureEl.innerHTML = '<div id="test"></div>'
+
+      const div = fixtureEl.querySelector('#test')
+
+      expect(makeArray(SelectorEngine.find('#test'))).toEqual([div])
+    })
+
+    it('should handle :scope selectors', () => {
+      fixtureEl.innerHTML = `<ul>
+        <li></li>
+        <li>
+          <a href="#" class="active">link</a>
+        </li>
+        <li></li>
+      </ul>`
+
+      const listEl = fixtureEl.querySelector('ul')
+      const aActive = fixtureEl.querySelector('.active')
+
+      expect(makeArray(SelectorEngine.find(':scope > li > .active', listEl))).toEqual([aActive])
+    })
+  })
+
+  describe('findOne', () => {
+    it('should return one element', () => {
+      fixtureEl.innerHTML = '<div id="test"></div>'
+
+      const div = fixtureEl.querySelector('#test')
+
+      expect(SelectorEngine.findOne('#test')).toEqual(div)
+    })
+  })
+
+  describe('children', () => {
+    it('should find children', () => {
+      fixtureEl.innerHTML = `<ul>
+        <li></li>
+        <li></li>
+        <li></li>
+      </ul>`
+
+      const list = fixtureEl.querySelector('ul')
+      const liList = makeArray(fixtureEl.querySelectorAll('li'))
+      const result = makeArray(SelectorEngine.children(list, 'li'))
+
+      expect(result).toEqual(liList)
+    })
+  })
+
+  describe('parents', () => {
+    it('should return parents', () => {
+      expect(SelectorEngine.parents(fixtureEl, 'body').length).toEqual(1)
+    })
+  })
+
+  describe('prev', () => {
+    it('should return previous element', () => {
+      fixtureEl.innerHTML = '<div class="test"></div><button class="btn"></button>'
+
+      const btn = fixtureEl.querySelector('.btn')
+      const divTest = fixtureEl.querySelector('.test')
+
+      expect(SelectorEngine.prev(btn, '.test')).toEqual([divTest])
+    })
+
+    it('should return previous element with an extra element between', () => {
+      fixtureEl.innerHTML = [
+        '<div class="test"></div>',
+        '<span></span>',
+        '<button class="btn"></button>'
+      ].join('')
+
+      const btn = fixtureEl.querySelector('.btn')
+      const divTest = fixtureEl.querySelector('.test')
+
+      expect(SelectorEngine.prev(btn, '.test')).toEqual([divTest])
+    })
+  })
+})
+