Add temporary test for language features

.airtap.yml

@@ -5,13 +5,13 @@ providers:
 browsers:
   - name: chrome
   - name: firefox
-  - name: safari
-    version: 11
-    platform: Mac 10.13 # https://github.com/airtap/sauce-browsers/issues/3
+  # - name: safari
+  #   version: 11
+  #   platform: Mac 10.13 # https://github.com/airtap/sauce-browsers/issues/3
   - name: safari
     version: 12..latest
   - name: ios_saf
-    version: 11..latest
+    version: 12..latest
   - name: chrome for android
     version: 6..latest
   - name: msedge

test/self.js

@@ -91,6 +91,76 @@ function implement (ctor, methods) {
   return Test
 }
 
+// Temporary test for browsers
+test('language features', function (t) {
+  const { foo } = { foo: 1 }
+  t.is(foo, 1)
+
+  // Rest/Spread Properties. Not on Safari < 11.1 (2018-04-12, 0.43%), Safari iOS < 11.3 (2018-03-29, 0.69%)
+  // https://github.com/tc39/proposal-object-rest-spread
+  const { a, ...rest } = { a: 1, b: 2, c: 3 }
+  t.is(a, 1)
+  t.same(Object.keys(rest), ['b', 'c'])
+
+  // Spread in object literals
+  // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Spread_syntax#spread_in_object_literals
+  t.same({ ...rest, c: 100 }, { b: 2, c: 100 }) // Not on Safari iOS < 11.3 (2018-03-29, 0.69%)
+
+  ;((...rest) => t.same(rest, [1, 2, 3]))(1, 2, 3)
+
+  const x = 9
+  for (const x of [10]) t.is(x, 10)
+  { const x = 11; t.is(x, 11) }
+  t.is(x, 9)
+
+  t.is(`foo ${88}`, 'foo 88')
+
+  class Test {}
+  t.is(typeof Test, 'function')
+  t.is(typeof global.Map, 'function', 'map')
+  t.is(typeof global.Set, 'function', 'set')
+  t.is(typeof String.prototype.startsWith, 'function', 'String#startsWith')
+  t.is(typeof String.prototype.includes, 'function', 'String#includes')
+  t.is(typeof Array.from, 'function', 'Array.from()')
+  t.is(typeof Number.isInteger, 'function', 'Number.isInteger')
+
+  const kA = Symbol('a')
+  const kB = Symbol('b')
+  const obj = { [kA]: true, [kB]: false }
+  t.is(obj[kA], true)
+  t.is(obj[kB], false)
+  t.is(typeof Symbol.for, 'function', 'global symbol registry')
+
+  new Promise((resolve) => resolve(123)).then((res) => {
+    t.is(res, 123)
+    t.end()
+  })
+})
+
+// Not on Safari < 12 (0.5%, 2018-09-17) and Safari iOS < 12 (0.78%, 2018-09-17)
+test('async generator', async function (t) {
+  let ended = false
+
+  async function * generator () {
+    try {
+      yield 1
+      yield 2
+      yield 3
+    } finally {
+      ended = true
+    }
+  }
+
+  const res = []
+
+  for await (const x of generator()) {
+    res.push(x)
+  }
+
+  t.same(res, [1, 2, 3])
+  t.is(ended, true)
+})
+
 /**
  * Extensibility
  */