chore(TypeScript): fix unit tests and coverage

test/unit/template.ts

@@ -1,13 +1,28 @@
 import { resolve } from '../../src/parser/template'
-import * as mock from 'mock-fs'
-import { expect } from 'chai'
 import * as path from 'path'
+import { fs } from 'src/parser/template'
+import { expect, use } from 'chai'
+import * as chaiAsPromised from 'chai-as-promised'
+
+use(chaiAsPromised)
 
 describe('template', function () {
+  let readFile, stat
   before(function () {
-    mock({
-      '/foo/bar.html': 'bar'
-    })
+    readFile = fs.readFile
+    stat = fs.stat
+    fs.readFile = async function (file) {
+      if (file === '/foo/bar.html') return 'bar'
+      throw new Error('NOENT')
+    }
+    fs.stat = async function (file) {
+      if (file === '/foo/bar.html') return { type: 'file' }
+      throw new Error('NOENT')
+    }
+  })
+  after(function () {
+    fs.readFile = readFile
+    fs.stat = stat
   })
   describe('#resolve()', function () {
     it('should resolve based on root', async function () {