Implement async generators (#3916)

JerryScript-DCO-1.0-Signed-off-by: Zoltan Herczeg zherczeg.u-szeged@partner.samsung.com

tests/jerry/es.next/function-async-gen1.js

@@ -0,0 +1,250 @@
+// Copyright JS Foundation and other contributors, http://js.foundation
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+var successCount = 0
+
+function check_fulfilled(p, value, done)
+{
+  assert(p instanceof Promise)
+
+  p.then(function(v) {
+    assert(v.value === value)
+    assert(v.done === done)
+    successCount++
+  }, function() {
+    assert(false)
+  })
+}
+
+function check_rejected(p, value)
+{
+  assert(p instanceof Promise)
+
+  p.then(function(v) {
+    assert(false)
+  }, function(v) {
+    assert(v === value)
+    successCount++
+  })
+}
+
+// Test 1
+
+var gen, r, o
+
+async function *f1(p, o) {
+  assert((yield "Test1") === "Test2")
+  await p
+
+  assert((yield 1.5) === 2.5)
+  await "String"
+
+  return o
+}
+
+assert(Object.prototype.toString.call(f1) === "[object AsyncGeneratorFunction]")
+
+o = {}
+gen = f1(new Promise(function(resolve, reject) { r = resolve }), o)
+
+assert(Object.prototype.toString.call(gen) === "[object AsyncGenerator]")
+
+check_fulfilled(gen.next(), "Test1", false)
+check_fulfilled(gen.next("Test2"), 1.5, false)
+check_fulfilled(gen.next(2.5), o, true)
+check_fulfilled(gen.next(), undefined, true)
+check_fulfilled(gen.next(), undefined, true)
+
+r(1)
+
+// Test 2
+
+async function *f2(o) {
+  try {
+    await {}
+    yield o
+    assert(false)
+  } catch (e) {
+    assert(e === "Throw")
+  }
+
+  try {
+    await "String"
+    yield 12
+    assert(false)
+  } catch (e) {
+    assert(e === o)
+
+    throw o
+  }
+}
+
+o = {}
+gen = f2(o)
+check_fulfilled(gen.next(), o, false)
+check_fulfilled(gen.throw("Throw"), 12, false)
+check_rejected(gen.throw(o), o)
+
+check_fulfilled(gen.next(), undefined, true)
+check_rejected(gen.throw(), undefined)
+check_fulfilled(gen.return(), undefined, true)
+
+// Test 3
+
+async function *f3() {
+  throw "Msg"
+}
+
+gen = f3()
+check_rejected(gen.next(), "Msg")
+gen = f3()
+check_rejected(gen.throw("End"), "End")
+
+// Test 4
+
+async function *f4() {
+  if (state === 0) {
+    state = 1;
+  }
+
+  await 1
+
+  if (state === 3) {
+    state = 4;
+  }
+}
+
+var state = 0
+gen = f4()
+gen.next()
+
+if (state === 1) {
+  state = 2
+}
+
+gen.next()
+
+if (state === 2) {
+  state = 3
+}
+
+// Test 5
+
+async function *f5() {
+  if (state2 === 0) {
+    state2 = 1;
+  }
+
+  yield 1
+
+  if (state2 === 3) {
+    state2 = 4;
+  }
+}
+
+var state2 = 0
+gen = f5()
+gen.next()
+
+if (state2 === 1) {
+  state2 = 2
+}
+
+gen.next()
+
+if (state2 === 2) {
+  state2 = 3
+}
+
+// Test 6
+
+async function *f6() {
+  return "Res"
+}
+
+var genLate = f6()
+var p = genLate.next()
+
+assert(p instanceof Promise)
+
+p.then(function(v) {
+  assert(v.value === "Res")
+  assert(v.done === true)
+  successCount++
+
+  check_fulfilled(genLate.next(), undefined, true)
+  var o = {}
+  check_rejected(genLate.throw(o), o)
+  check_fulfilled(genLate.return(), undefined, true)
+}, function() {
+  assert(false)
+})
+
+// Test 7
+
+var AsyncGeneratorFun = Object.getPrototypeOf(async function *() {}).constructor;
+
+o = {}
+gen = AsyncGeneratorFun("p, o, x = 5.5", "assert((await p) === 'P'); yield o; return x")
+gen = gen(new Promise(function(resolve, reject) { r = resolve }), o)
+
+check_fulfilled(gen.next(), o, false)
+check_fulfilled(gen.next(), 5.5, true)
+check_fulfilled(gen.next(), undefined, true)
+check_fulfilled(gen.next(), undefined, true)
+
+r("P")
+
+// Test 8
+
+async function *f8() {
+  var o = {}
+  function f() {}
+
+  check_fulfilled(selfGen.next(), o, false)
+  check_fulfilled(selfGen.next(), f, true)
+  check_fulfilled(selfGen.next(), undefined, true)
+
+  yield "Str"
+  yield o
+  return f
+}
+
+var selfGen = f8();
+check_fulfilled(selfGen.next(), "Str", false)
+
+// Test 9
+
+async function *f9() {
+  try {
+    yield "X"
+  } finally {
+    successCount++;
+  }
+  yield "Y"
+  return 1;
+}
+
+gen = f9()
+check_fulfilled(gen.next(), "X", false)
+check_fulfilled(gen.return("Ret"), "Ret", true)
+check_fulfilled(gen.next(), undefined, true)
+
+// END
+
+function __checkAsync() {
+  assert(successCount === 29)
+  assert(state === 4)
+  assert(state2 === 4)
+}