Add cases for yield stars flow

src/async-generators/yield-star-async-next.case

+// Copyright 2017 Tooru Fujisawa. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+desc: Execution order for yield* with async iterator and next()
+template: default
+info: |
+YieldExpression: yield * AssignmentExpression
+
+    ...
+    2. Let value be ? GetValue(exprRef).
+    3. Let generatorKind be ! GetGeneratorKind().
+    4. Let iterator be ? GetIterator(value, generatorKind).
+    5. Let received be NormalCompletion(undefined).
+    6. Repeat
+      a. If received.[[Type]] is normal, then
+        i. Let innerResult be ? IteratorNext(iterator, received.[[Value]]).
+        ii. Let innerResult be ? Invoke(iterator, "next",
+            « received.[[Value]] »).
+        iii. If generatorKind is async, then set innerResult to
+             ? Await(innerResult).
+        ...
+        v. Let done be ? IteratorComplete(innerResult).
+        vi. If done is true, then
+           1. Return ? IteratorValue(innerResult).
+        vii. Let received be GeneratorYield(innerResult).
+      ...
+
+    GetIterator ( obj [ , hint ] )
+
+    ...
+    3. If hint is async,
+      a. Set method to ? GetMethod(obj, @@asyncIterator).
+      b. If method is undefined,
+        i. Let syncMethod be ? GetMethod(obj, @@iterator).
+        ii. Let syncIterator be ? Call(syncMethod, obj).
+        iii. Return ? CreateAsyncFromSyncIterator(syncIterator).
+    ...
+
+    GeneratorYield ( iterNextObj )
+
+    ...
+    10. If generatorKind is async,
+      a. Let value be IteratorValue(iterNextObj).
+      b. Let done be IteratorComplete(iterNextObj).
+      c. Return ! AsyncGeneratorResolve(generator, value, done).
+    ...
+
+flags: [async]
+features: [async-iteration, Symbol.asyncIterator]
+---*/
+
+//- setup
+var log = [];
+var obj = {
+  get [Symbol.iterator]() {
+    log.push({ name: "get [Symbol.iterator]" });
+  },
+  get [Symbol.asyncIterator]() {
+    log.push({
+      name: "get [Symbol.asyncIterator]",
+      thisValue: this
+    });
+    return function() {
+      log.push({
+        name: "call [Symbol.asyncIterator]",
+        thisValue: this,
+        args: [...arguments]
+      });
+      var nextCount = 0;
+      return {
+        name: "asyncIterator",
+        get next() {
+          log.push({
+            name: "get next",
+            thisValue: this
+          });
+          return function() {
+            log.push({
+              name: "call next",
+              thisValue: this,
+              args: [...arguments]
+            });
+
+            nextCount++;
+            if (nextCount == 1) {
+              return {
+                name: "next-promise-1",
+                get then() {
+                  log.push({
+                    name: "get next then (1)",
+                    thisValue: this
+                  });
+                  return function(resolve) {
+                    log.push({
+                      name: "call next then (1)",
+                      thisValue: this,
+                      args: [...arguments]
+                    });
+
+                    resolve({
+                      name: "next-result-1",
+                      get value() {
+                        log.push({
+                          name: "get next value (1)",
+                          thisValue: this
+                        });
+                        return "next-value-1";
+                      },
+                      get done() {
+                        log.push({
+                          name: "get next done (1)",
+                          thisValue: this
+                        });
+                        return false;
+                      }
+                    });
+                  };
+                }
+              };
+            }
+
+            return {
+              name: "next-promise-2",
+              get then() {
+                log.push({
+                  name: "get next then (2)",
+                  thisValue: this
+                });
+                return function(resolve) {
+                  log.push({
+                    name: "call next then (2)",
+                    thisValue: this,
+                    args: [...arguments]
+                  });
+
+                  resolve({
+                    name: "next-result-2",
+                    get value() {
+                      log.push({
+                        name: "get next value (2)",
+                        thisValue: this
+                      });
+                      return "next-value-2";
+                    },
+                    get done() {
+                      log.push({
+                        name: "get next done (2)",
+                        thisValue: this
+                      });
+                      return true;
+                    }
+                  });
+                };
+              }
+            };
+          };
+        }
+      };
+    };
+  }
+};
+
+//- body
+  log.push({ name: "before yield*" });
+  var v = yield* obj;
+  log.push({
+    name: "after yield*",
+    value: v
+  });
+  return "return-value";
+
+//- assertions
+assert.sameValue(log.length, 0, "log.length");
+
+iter.next("next-arg-1").then(v => {
+  assert.sameValue(log[0].name, "before yield*");
+
+  assert.sameValue(log[1].name, "get [Symbol.asyncIterator]");
+  assert.sameValue(log[1].thisValue, obj, "get [Symbol.asyncIterator] thisValue");
+
+  assert.sameValue(log[2].name, "call [Symbol.asyncIterator]");
+  assert.sameValue(log[2].thisValue, obj, "[Symbol.asyncIterator] thisValue");
+  assert.sameValue(log[2].args.length, 0, "[Symbol.asyncIterator] args.length");
+
+  assert.sameValue(log[3].name, "get next");
+  assert.sameValue(log[3].thisValue.name, "asyncIterator", "get next thisValue");
+
+  assert.sameValue(log[4].name, "call next");
+  assert.sameValue(log[4].thisValue.name, "asyncIterator", "next thisValue");
+  assert.sameValue(log[4].args.length, 1, "next args.length");
+  assert.sameValue(log[4].args[0], undefined, "next args[0]");
+
+  assert.sameValue(log[5].name, "get next then (1)");
+  assert.sameValue(log[5].thisValue.name, "next-promise-1", "get next then thisValue");
+
+  assert.sameValue(log[6].name, "call next then (1)");
+  assert.sameValue(log[6].thisValue.name, "next-promise-1", "next then thisValue");
+  assert.sameValue(log[6].args.length, 2, "next then args.length");
+  assert.sameValue(typeof log[6].args[0], "function", "next then args[0]");
+  assert.sameValue(typeof log[6].args[1], "function", "next then args[1]");
+
+  assert.sameValue(log[7].name, "get next done (1)");
+  assert.sameValue(log[7].thisValue.name, "next-result-1", "get next done thisValue");
+
+  assert.sameValue(log[8].name, "get next value (1)");
+  assert.sameValue(log[8].thisValue.name, "next-result-1", "get next value thisValue");
+
+  assert.sameValue(log[9].name, "get next done (1)");
+  assert.sameValue(log[9].thisValue.name, "next-result-1", "get next done thisValue");
+
+  assert.sameValue(v.value, "next-value-1");
+  assert.sameValue(v.done, false);
+
+  assert.sameValue(log.length, 10, "log.length");
+
+  iter.next("next-arg-2").then(v => {
+    assert.sameValue(log[10].name, "get next");
+    assert.sameValue(log[10].thisValue.name, "asyncIterator", "get next thisValue");
+
+    assert.sameValue(log[11].name, "call next");
+    assert.sameValue(log[11].thisValue.name, "asyncIterator", "next thisValue");
+    assert.sameValue(log[11].args.length, 1, "next args.length");
+    assert.sameValue(log[11].args[0], "next-arg-2", "next args[0]");
+
+    assert.sameValue(log[12].name, "get next then (2)");
+    assert.sameValue(log[12].thisValue.name, "next-promise-2", "get next then thisValue");
+
+    assert.sameValue(log[13].name, "call next then (2)");
+    assert.sameValue(log[13].thisValue.name, "next-promise-2", "next then thisValue");
+    assert.sameValue(log[13].args.length, 2, "next then args.length");
+    assert.sameValue(typeof log[13].args[0], "function", "next then args[0]");
+    assert.sameValue(typeof log[13].args[1], "function", "next then args[1]");
+
+    assert.sameValue(log[14].name, "get next done (2)");
+    assert.sameValue(log[14].thisValue.name, "next-result-2", "get next done thisValue");
+
+    assert.sameValue(log[15].name, "get next value (2)");
+    assert.sameValue(log[15].thisValue.name, "next-result-2", "get next value thisValue");
+
+    assert.sameValue(log[16].name, "after yield*");
+    assert.sameValue(log[16].value, "next-value-2");
+
+    assert.sameValue(v.value, "return-value");
+    assert.sameValue(v.done, true);
+
+    assert.sameValue(log.length, 17, "log.length");
+  }).then($DONE, $DONE);
+}).catch($DONE);

src/async-generators/yield-star-async-return.case

+// Copyright 2017 Tooru Fujisawa. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+template: default
+desc: execution order for yield* with async iterator and return()
+info: |
+    YieldExpression: yield * AssignmentExpression
+
+    ...
+    6. Repeat
+      ...
+      c. Else,
+        i. Assert: received.[[Type]] is return.
+        ii. Let return be ? GetMethod(iterator, "return").
+        iii. If return is undefined, return Completion(received).
+        iv. Let innerReturnResult be ? Call(return, iterator,
+            « received.[[Value]] »).
+        v. If generatorKind is async, then set innerReturnResult to
+           ? Await(innerReturnResult).
+        ...
+        vii. Let done be ? IteratorComplete(innerReturnResult).
+        viii. If done is true, then
+             1. Let value be ? IteratorValue(innerReturnResult).
+             2. Return Completion{[[Type]]: return, [[Value]]: value,
+                [[Target]]: empty}.
+        ix. Let received be GeneratorYield(innerResult).
+
+    GeneratorYield ( iterNextObj )
+
+    ...
+    10. If generatorKind is async,
+      a. Let value be IteratorValue(iterNextObj).
+      b. Let done be IteratorComplete(iterNextObj).
+      c. Return ! AsyncGeneratorResolve(generator, value, done).
+    ...
+
+flags: [async]
+features: [async-iteration, Symbol.asyncIterator]
+---*/
+
+//- setup
+var log = [];
+var obj = {
+  [Symbol.asyncIterator]() {
+    var returnCount = 0;
+    return {
+      name: 'asyncIterator',
+      get next() {
+        log.push({ name: "get next" });
+        return function() {
+          return {
+            value: "next-value-1",
+            done: false
+          };
+        };
+      },
+      get return() {
+        log.push({
+          name: "get return",
+          thisValue: this
+        });
+        return function() {
+          log.push({
+            name: "call return",
+            thisValue: this,
+            args: [...arguments]
+          });
+
+          returnCount++;
+          if (returnCount == 1) {
+            return {
+              name: "return-promise-1",
+              get then() {
+                log.push({
+                  name: "get return then (1)",
+                  thisValue: this
+                });
+                return function(resolve) {
+                  log.push({
+                    name: "call return then (1)",
+                    thisValue: this,
+                    args: [...arguments]
+                  });
+
+                  resolve({
+                    name: "return-result-1",
+                    get value() {
+                      log.push({
+                        name: "get return value (1)",
+                        thisValue: this
+                      });
+                      return "return-value-1";
+                    },
+                    get done() {
+                      log.push({
+                        name: "get return done (1)",
+                        thisValue: this
+                      });
+                      return false;
+                    }
+                  });
+                };
+              }
+            };
+          }
+
+          return {
+            name: "return-promise-2",
+            get then() {
+              log.push({
+                name: "get return then (2)",
+                thisValue: this
+              });
+              return function(resolve) {
+                log.push({
+                  name: "call return then (2)",
+                  thisValue: this,
+                  args: [...arguments]
+                });
+
+                resolve({
+                  name: "return-result-2",
+                  get value() {
+                    log.push({
+                      name: "get return value (2)",
+                      thisValue: this
+                    });
+                    return "return-value-2";
+                  },
+                  get done() {
+                    log.push({
+                      name: "get return done (2)",
+                      thisValue: this
+                    });
+                    return true;
+                  }
+                });
+              };
+            }
+          };
+        };
+      }
+    };
+  }
+};
+
+//- body
+  log.push({ name: "before yield*" });
+  yield* obj;
+
+//- assertions
+assert.sameValue(log.length, 0, "log.length");
+
+iter.next().then(v => {
+  assert.sameValue(log[0].name, "before yield*");
+
+  assert.sameValue(log[1].name, "get next");
+
+  assert.sameValue(v.value, "next-value-1");
+  assert.sameValue(v.done, false);
+
+  assert.sameValue(log.length, 2, "log.length");
+
+  iter.return("return-arg-1").then(v => {
+    assert.sameValue(log[2].name, "get return");
+    assert.sameValue(log[2].thisValue.name, "asyncIterator", "get return thisValue");
+
+    assert.sameValue(log[3].name, "call return");
+    assert.sameValue(log[3].thisValue.name, "asyncIterator", "return thisValue");
+    assert.sameValue(log[3].args.length, 1, "return args.length");
+    assert.sameValue(log[3].args[0], "return-arg-1", "return args[0]");
+
+    assert.sameValue(log[4].name, "get return then (1)");
+    assert.sameValue(log[4].thisValue.name, "return-promise-1", "get return then thisValue");
+
+    assert.sameValue(log[5].name, "call return then (1)");
+    assert.sameValue(log[5].thisValue.name, "return-promise-1", "return then thisValue");
+    assert.sameValue(log[5].args.length, 2, "return then args.length");
+    assert.sameValue(typeof log[5].args[0], "function", "return then args[0]");
+    assert.sameValue(typeof log[5].args[1], "function", "return then args[1]");
+
+    assert.sameValue(log[6].name, "get return done (1)");
+    assert.sameValue(log[6].thisValue.name, "return-result-1", "get return done thisValue");
+
+    assert.sameValue(log[7].name, "get return value (1)");
+    assert.sameValue(log[7].thisValue.name, "return-result-1", "get return value thisValue");
+
+    assert.sameValue(log[8].name, "get return done (1)");
+    assert.sameValue(log[8].thisValue.name, "return-result-1", "get return done thisValue");
+
+    assert.sameValue(v.value, "return-value-1");
+    assert.sameValue(v.done, false);
+
+    assert.sameValue(log.length, 9, "log.length");
+
+    iter.return("return-arg-2").then(v => {
+      assert.sameValue(log[9].name, "get return");
+      assert.sameValue(log[9].thisValue.name, "asyncIterator", "get return thisValue");
+
+      assert.sameValue(log[10].name, "call return");
+      assert.sameValue(log[10].thisValue.name, "asyncIterator", "return thisValue");
+      assert.sameValue(log[10].args.length, 1, "return args.length");
+      assert.sameValue(log[10].args[0], "return-arg-2", "return args[0]");
+
+      assert.sameValue(log[11].name, "get return then (2)");
+      assert.sameValue(log[11].thisValue.name, "return-promise-2", "get return then thisValue");
+
+      assert.sameValue(log[12].name, "call return then (2)");
+      assert.sameValue(log[12].thisValue.name, "return-promise-2", "return then thisValue");
+      assert.sameValue(log[12].args.length, 2, "return then args.length");
+      assert.sameValue(typeof log[12].args[0], "function", "return then args[0]");
+      assert.sameValue(typeof log[12].args[1], "function", "return then args[1]");
+
+      assert.sameValue(log[13].name, "get return done (2)");
+      assert.sameValue(log[13].thisValue.name, "return-result-2", "get return done thisValue");
+
+      assert.sameValue(log[14].name, "get return value (2)");
+      assert.sameValue(log[14].thisValue.name, "return-result-2", "get return value thisValue");
+
+      assert.sameValue(v.value, "return-value-2");
+      assert.sameValue(v.done, true);
+
+      assert.sameValue(log.length, 15, "log.length");
+    }).then($DONE, $DONE);
+  }).catch($DONE);
+}).catch($DONE);

src/async-generators/yield-star-async-throw.case

+// Copyright 2017 Tooru Fujisawa. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+template: default
+desc: execution order for yield* with async iterator and throw()
+info: |
+    YieldExpression: yield * AssignmentExpression
+
+    ...
+    6. Repeat
+      ...
+      b. Else if received.[[Type]] is throw, then
+        i. Let throw be ? GetMethod(iterator, "throw").
+        ii. If throw is not undefined, then
+          1. Let innerResult be ? Call(throw, iterator, « received.[[Value]] »).
+          2. If generatorKind is async, then set innerResult to
+             ? Await(innerResult).
+          ...
+          5. Let done be ? IteratorComplete(innerResult).
+          6. If done is true, then
+            a. Return ? IteratorValue(innerResult).
+          7. Let received be GeneratorYield(innerResult).
+      ...
+
+    GeneratorYield ( iterNextObj )
+
+    ...
+    10. If generatorKind is async,
+      a. Let value be IteratorValue(iterNextObj).
+      b. Let done be IteratorComplete(iterNextObj).
+      c. Return ! AsyncGeneratorResolve(generator, value, done).
+    ...
+
+flags: [async]
+features: [async-iteration, Symbol.asyncIterator]
+---*/
+
+//- setup
+var log = [];
+var obj = {
+  [Symbol.asyncIterator]() {
+    var throwCount = 0;
+    return {
+      name: "asyncIterator",
+      get next() {
+        log.push({ name: "get next" });
+        return function() {
+          return {
+            value: "next-value-1",
+            done: false
+          };
+        };
+      },
+      get throw() {
+        log.push({
+          name: "get throw",
+          thisValue: this
+        });
+        return function() {
+          log.push({
+            name: "call throw",
+            thisValue: this,
+            args: [...arguments]
+          });
+
+          throwCount++;
+          if (throwCount == 1) {
+            return {
+              name: "throw-promise-1",
+              get then() {
+                log.push({
+                  name: "get throw then (1)",
+                  thisValue: this
+                });
+                return function(resolve) {
+                  log.push({
+                    name: "call throw then (1)",
+                    thisValue: this,
+                    args: [...arguments]
+                  });
+
+                  resolve({
+                    name: "throw-result-1",
+                    get value() {
+                      log.push({
+                        name: "get throw value (1)",
+                        thisValue: this
+                      });
+                      return "throw-value-1";
+                    },
+                    get done() {
+                      log.push({
+                        name: "get throw done (1)",
+                        thisValue: this
+                      });
+                      return false;
+                    }
+                  });
+                };
+              }
+            };
+          }
+
+          return {
+            name: "throw-promise-2",
+            get then() {
+              log.push({
+                name: "get throw then (2)",
+                thisValue: this
+              });
+              return function(resolve) {
+                log.push({
+                  name: "call throw then (2)",
+                  thisValue: this,
+                  args: [...arguments]
+                });
+
+                resolve({
+                  name: "throw-result-2",
+                  get value() {
+                    log.push({
+                      name: "get throw value (2)",
+                      thisValue: this
+                    });
+                    return "throw-value-2";
+                  },
+                  get done() {
+                    log.push({
+                      name: "get throw done (2)",
+                      thisValue: this
+                    });
+                    return true;
+                  }
+                });
+              };
+            }
+          };
+        };
+      }
+    };
+  }
+};
+
+//- body
+  log.push({ name: "before yield*" });
+  var v = yield* obj;
+  log.push({
+    name: "after yield*",
+    value: v
+  });
+  return "return-value";
+
+//- assertions
+assert.sameValue(log.length, 0, "log.length");
+
+iter.next().then(v => {
+  assert.sameValue(log[0].name, "before yield*");
+
+  assert.sameValue(log[1].name, "get next");
+
+  assert.sameValue(v.value, "next-value-1");
+  assert.sameValue(v.done, false);
+
+  assert.sameValue(log.length, 2, "log.length");
+
+  iter.throw("throw-arg-1").then(v => {
+    assert.sameValue(log[2].name, "get throw");
+    assert.sameValue(log[2].thisValue.name, "asyncIterator", "get throw thisValue");
+
+    assert.sameValue(log[3].name, "call throw");
+    assert.sameValue(log[3].thisValue.name, "asyncIterator", "throw thisValue");
+    assert.sameValue(log[3].args.length, 1, "throw args.length");
+    assert.sameValue(log[3].args[0], "throw-arg-1", "throw args[0]");
+
+    assert.sameValue(log[4].name, "get throw then (1)");
+    assert.sameValue(log[4].thisValue.name, "throw-promise-1", "get throw thisValue");
+
+    assert.sameValue(log[5].name, "call throw then (1)");
+    assert.sameValue(log[5].thisValue.name, "throw-promise-1", "throw thisValue");
+    assert.sameValue(log[5].args.length, 2, "throw then args.length");
+    assert.sameValue(typeof log[5].args[0], "function", "throw then args[0]");
+    assert.sameValue(typeof log[5].args[1], "function", "throw then args[1]");
+
+    assert.sameValue(log[6].name, "get throw done (1)");
+    assert.sameValue(log[6].thisValue.name, "throw-result-1", "get throw done thisValue");
+
+    assert.sameValue(log[7].name, "get throw value (1)");
+    assert.sameValue(log[7].thisValue.name, "throw-result-1", "get throw value thisValue");
+
+    assert.sameValue(log[8].name, "get throw done (1)");
+    assert.sameValue(log[8].thisValue.name, "throw-result-1", "get throw done thisValue");
+
+    assert.sameValue(v.value, "throw-value-1");
+    assert.sameValue(v.done, false);
+
+    assert.sameValue(log.length, 9, "log.length");
+
+    iter.throw("throw-arg-2").then(v => {
+      assert.sameValue(log[9].name, "get throw");
+      assert.sameValue(log[9].thisValue.name, "asyncIterator", "get throw thisValue");
+
+      assert.sameValue(log[10].name, "call throw");
+      assert.sameValue(log[10].thisValue.name, "asyncIterator", "throw thisValue");
+      assert.sameValue(log[10].args.length, 1, "throw args.length");
+      assert.sameValue(log[10].args[0], "throw-arg-2", "throw args[0]");
+
+      assert.sameValue(log[11].name, "get throw then (2)");
+      assert.sameValue(log[11].thisValue.name, "throw-promise-2", "get throw thisValue");
+
+      assert.sameValue(log[12].name, "call throw then (2)");
+      assert.sameValue(log[12].thisValue.name, "throw-promise-2", "throw thisValue");
+      assert.sameValue(log[12].args.length, 2, "throw then args.length");
+      assert.sameValue(typeof log[12].args[0], "function", "throw then args[0]");
+      assert.sameValue(typeof log[12].args[1], "function", "throw then args[1]");
+
+      assert.sameValue(log[13].name, "get throw done (2)");
+      assert.sameValue(log[13].thisValue.name, "throw-result-2", "get throw done thisValue");
+
+      assert.sameValue(log[14].name, "get throw value (2)");
+      assert.sameValue(log[14].thisValue.name, "throw-result-2", "get throw value thisValue");
+
+      assert.sameValue(log[15].name, "after yield*");
+      assert.sameValue(log[15].value, "throw-value-2");
+
+      assert.sameValue(v.value, "return-value");
+      assert.sameValue(v.done, true);
+
+      assert.sameValue(log.length, 16, "log.length");
+    }).then($DONE, $DONE);
+  }).catch($DONE);
+}).catch($DONE);

src/async-generators/yield-star-sync-next.case

+// Copyright 2017 Tooru Fujisawa. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+template: default
+desc: execution order for yield* with sync iterator and next()
+info: |
+    YieldExpression: yield * AssignmentExpression
+
+    ...
+    2. Let value be ? GetValue(exprRef).
+    3. Let generatorKind be ! GetGeneratorKind().
+    4. Let iterator be ? GetIterator(value, generatorKind).
+    5. Let received be NormalCompletion(undefined).
+    6. Repeat
+      a. If received.[[Type]] is normal, then
+        i. Let innerResult be ? IteratorNext(iterator, received.[[Value]]).
+        ii. Let innerResult be ? Invoke(iterator, "next",
+            « received.[[Value]] »).
+        iii. If generatorKind is async, then set innerResult to
+             ? Await(innerResult).
+        ...
+        v. Let done be ? IteratorComplete(innerResult).
+        vi. If done is true, then
+           1. Return ? IteratorValue(innerResult).
+        vii. Let received be GeneratorYield(innerResult).
+      ...
+
+    GetIterator ( obj [ , hint ] )
+
+    ...
+    3. If hint is async,
+      a. Set method to ? GetMethod(obj, @@asyncIterator).
+      b. If method is undefined,
+        i. Let syncMethod be ? GetMethod(obj, @@iterator).
+        ii. Let syncIterator be ? Call(syncMethod, obj).
+        iii. Return ? CreateAsyncFromSyncIterator(syncIterator).
+    ...
+
+    %AsyncFromSyncIteratorPrototype%.next ( value )
+
+    ...
+    5. Let nextResult be IteratorNext(syncIterator, value).
+    ...
+    7. Let nextValue be IteratorValue(nextResult).
+    ...
+    9. Let nextDone be IteratorComplete(nextResult).
+    ...
+    12. Perform ! Call(valueWrapperCapability.[[Resolve]], undefined,
+        « nextValue »).
+    ...
+    14. Set onFulfilled.[[Done]] to nextDone.
+    15. Perform ! PerformPromiseThen(valueWrapperCapability.[[Promise]],
+        onFulfilled, undefined, promiseCapability).
+    ...
+
+    Async Iterator Value Unwrap Functions
+
+    1. Return ! CreateIterResultObject(value, F.[[Done]]).
+
+flags: [async]
+features: [async-iteration, Symbol.asyncIterator]
+---*/
+
+//- setup
+var log = [];
+var obj = {
+  get [Symbol.iterator]() {
+    log.push({
+      name: "get [Symbol.iterator]",
+      thisValue: this
+    });
+    return function() {
+      log.push({
+        name: "call [Symbol.iterator]",
+        thisValue: this,
+        args: [...arguments]
+      });
+      var nextCount = 0;
+      return {
+        name: "syncIterator",
+        get next() {
+          log.push({
+            name: "get next",
+            thisValue: this
+          });
+          return function() {
+            log.push({
+              name: "call next",
+              thisValue: this,
+              args: [...arguments]
+            });
+
+            nextCount++;
+            if (nextCount == 1) {
+              return {
+                name: "next-result-1",
+                get value() {
+                  log.push({
+                    name: "get next value (1)",
+                    thisValue: this
+                  });
+                  return "next-value-1";
+                },
+                get done() {
+                  log.push({
+                    name: "get next done (1)",
+                    thisValue: this
+                  });
+                  return false;
+                }
+              };
+            }
+
+            return {
+              name: "next-result-2",
+              get value() {
+                log.push({
+                  name: "get next value (2)",
+                  thisValue: this
+                });
+                return "next-value-2";
+              },
+              get done() {
+                log.push({
+                  name: "get next done (2)",
+                  thisValue: this
+                });
+                return true;
+              }
+            };
+          };
+        }
+      };
+    };
+  },
+  get [Symbol.asyncIterator]() {
+    log.push({ name: "get [Symbol.asyncIterator]" });
+    return null;
+  }
+};
+
+//- body
+  log.push({ name: "before yield*" });
+  var v = yield* obj;
+  log.push({
+    name: "after yield*",
+    value: v
+  });
+  return "return-value";
+
+//- assertions
+assert.sameValue(log.length, 0, "log.length");
+
+iter.next("next-arg-1").then(v => {
+  assert.sameValue(log[0].name, "before yield*");
+
+  assert.sameValue(log[1].name, "get [Symbol.asyncIterator]");
+
+  assert.sameValue(log[2].name, "get [Symbol.iterator]");
+  assert.sameValue(log[2].thisValue, obj, "get [Symbol.iterator] thisValue");
+
+  assert.sameValue(log[3].name, "call [Symbol.iterator]");
+  assert.sameValue(log[3].thisValue, obj, "[Symbol.iterator] thisValue");
+  assert.sameValue(log[3].args.length, 0, "[Symbol.iterator] args.length");
+
+  assert.sameValue(log[4].name, "get next");
+  assert.sameValue(log[4].thisValue.name, "syncIterator", "get next thisValue");
+
+  assert.sameValue(log[5].name, "call next");
+  assert.sameValue(log[5].thisValue.name, "syncIterator", "next thisValue");
+  assert.sameValue(log[5].args.length, 1, "next args.length");
+  assert.sameValue(log[5].args[0], undefined, "next args[0]");
+
+  assert.sameValue(log[6].name, "get next value (1)");
+  assert.sameValue(log[6].thisValue.name, "next-result-1", "get next value thisValue");
+
+  assert.sameValue(log[7].name, "get next done (1)");
+  assert.sameValue(log[7].thisValue.name, "next-result-1", "get next done thisValue");
+
+  assert.sameValue(v.value, "next-value-1");
+  assert.sameValue(v.done, false);
+
+  assert.sameValue(log.length, 8, "log.length");
+
+  iter.next("next-arg-2").then(v => {
+    assert.sameValue(log[8].name, "get next");
+    assert.sameValue(log[8].thisValue.name, "syncIterator", "get next thisValue");
+
+    assert.sameValue(log[9].name, "call next");
+    assert.sameValue(log[9].thisValue.name, "syncIterator", "next thisValue");
+    assert.sameValue(log[9].args.length, 1, "next args.length");
+    assert.sameValue(log[9].args[0], "next-arg-2", "next args[0]");
+
+    assert.sameValue(log[10].name, "get next value (2)");
+    assert.sameValue(log[10].thisValue.name, "next-result-2", "get next value thisValue");
+
+    assert.sameValue(log[11].name, "get next done (2)");
+    assert.sameValue(log[11].thisValue.name, "next-result-2", "get next done thisValue");
+
+    assert.sameValue(log[12].name, "after yield*");
+    assert.sameValue(log[12].value, "next-value-2");
+
+    assert.sameValue(v.value, "return-value");
+    assert.sameValue(v.done, true);
+
+    assert.sameValue(log.length, 13, "log.length");
+  }).then($DONE, $DONE);
+}).catch($DONE);

src/async-generators/yield-star-sync-return.case

+// Copyright 2017 Tooru Fujisawa. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+template: default
+desc: execution order for yield* with sync iterator and return()
+info: |
+    YieldExpression: yield * AssignmentExpression
+
+    ...
+    6. Repeat
+      ...
+      c. Else,
+        i. Assert: received.[[Type]] is return.
+        ii. Let return be ? GetMethod(iterator, "return").
+        iii. If return is undefined, return Completion(received).
+        iv. Let innerReturnResult be ? Call(return, iterator,
+            « received.[[Value]] »).
+        v. If generatorKind is async, then set innerReturnResult to
+           ? Await(innerReturnResult).
+        ...
+        vii. Let done be ? IteratorComplete(innerReturnResult).
+        viii. If done is true, then
+             1. Let value be ? IteratorValue(innerReturnResult).
+             2. Return Completion{[[Type]]: return, [[Value]]: value,
+                [[Target]]: empty}.
+        ix. Let received be GeneratorYield(innerResult).
+
+    %AsyncFromSyncIteratorPrototype%.return ( value )
+
+    5. Let return be GetMethod(syncIterator, "return").
+    ...
+    ...
+    8. Let returnResult be Call(return, syncIterator, « value »).
+    ...
+    11. Let returnValue be IteratorValue(returnResult).
+    ..
+    13. Let returnDone be IteratorComplete(returnResult).
+    ...
+    16. Perform ! Call(valueWrapperCapability.[[Resolve]], undefined, « returnValue »).
+    ...
+    18. Set onFulfilled.[[Done]] to returnDone.
+    19. Perform ! PerformPromiseThen(valueWrapperCapability.[[Promise]],
+        onFulfilled, undefined, promiseCapability).
+    ...
+
+flags: [async]
+features: [async-iteration, Symbol.asyncIterator]
+---*/
+
+//- setup
+var log = [];
+var obj = {
+  [Symbol.iterator]() {
+    var returnCount = 0;
+    return {
+      name: "syncIterator",
+      get next() {
+        log.push({ name: "get next" });
+        return function() {
+          return {
+            value: "next-value-1",
+            done: false
+          };
+        };
+      },
+      get return() {
+        log.push({
+          name: "get return",
+          thisValue: this
+        });
+        return function() {
+          log.push({
+            name: "call return",
+            thisValue: this,
+            args: [...arguments]
+          });
+
+          returnCount++;
+          if (returnCount == 1) {
+            return {
+              name: "return-result-1",
+              get value() {
+                log.push({
+                  name: "get return value (1)",
+                  thisValue: this
+                });
+                return "return-value-1";
+              },
+              get done() {
+                log.push({
+                  name: "get return done (1)",
+                  thisValue: this
+                });
+                return false;
+              }
+            };
+          }
+
+          return {
+            name: "return-result-2",
+            get value() {
+              log.push({
+                name: "get return value (2)",
+                thisValue: this
+              });
+              return "return-value-2";
+            },
+            get done() {
+              log.push({
+                name: "get return done (2)",
+                thisValue: this
+              });
+              return true;
+            }
+          };
+        };
+      }
+    };
+  }
+};
+
+//- body
+  log.push({ name: "before yield*" });
+  yield* obj;
+
+//- assertions
+assert.sameValue(log.length, 0, "log.length");
+
+iter.next().then(v => {
+  assert.sameValue(log[0].name, "before yield*");
+
+  assert.sameValue(log[1].name, "get next");
+
+  assert.sameValue(v.value, "next-value-1");
+  assert.sameValue(v.done, false);
+
+  assert.sameValue(log.length, 2, "log.length");
+
+  iter.return("return-arg-1").then(v => {
+    assert.sameValue(log[2].name, "get return");
+    assert.sameValue(log[2].thisValue.name, "syncIterator", "get return thisValue");
+
+    assert.sameValue(log[3].name, "call return");
+    assert.sameValue(log[3].thisValue.name, "syncIterator", "return thisValue");
+    assert.sameValue(log[3].args.length, 1, "return args.length");
+    assert.sameValue(log[3].args[0], "return-arg-1", "return args[0]");
+
+    assert.sameValue(log[4].name, "get return value (1)");
+    assert.sameValue(log[4].thisValue.name, "return-result-1", "get return value thisValue");
+
+    assert.sameValue(log[5].name, "get return done (1)");
+    assert.sameValue(log[5].thisValue.name, "return-result-1", "get return done thisValue");
+
+    assert.sameValue(v.value, "return-value-1");
+    assert.sameValue(v.done, false);
+
+    assert.sameValue(log.length, 6, "log.length");
+
+    iter.return("return-arg-2").then(v => {
+      assert.sameValue(log[6].name, "get return");
+      assert.sameValue(log[6].thisValue.name, "syncIterator", "get return thisValue");
+
+      assert.sameValue(log[7].name, "call return");
+      assert.sameValue(log[7].thisValue.name, "syncIterator", "get return thisValue");
+      assert.sameValue(log[7].args.length, 1, "return args.length");
+      assert.sameValue(log[7].args[0], "return-arg-2", "return args[0]");
+
+      assert.sameValue(log[8].name, "get return value (2)");
+      assert.sameValue(log[8].thisValue.name, "return-result-2", "get return value thisValue");
+
+      assert.sameValue(log[9].name, "get return done (2)");
+      assert.sameValue(log[9].thisValue.name, "return-result-2", "get return done thisValue");
+
+      assert.sameValue(v.value, "return-value-2");
+      assert.sameValue(v.done, true);
+
+      assert.sameValue(log.length, 10, "log.length");
+    }).then($DONE, $DONE);
+  }).catch($DONE);
+}).catch($DONE);

src/async-generators/yield-star-sync-throw.case

+// Copyright 2017 Tooru Fujisawa. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+template: default
+desc: execution order for yield* with sync iterator and throw()
+info: |
+    YieldExpression: yield * AssignmentExpression
+
+    ...
+    6. Repeat
+      ...
+      b. Else if received.[[Type]] is throw, then
+        i. Let throw be ? GetMethod(iterator, "throw").
+        ii. If throw is not undefined, then
+          1. Let innerResult be ? Call(throw, iterator, « received.[[Value]] »).
+          2. If generatorKind is async, then set innerResult to
+             ? Await(innerResult).
+          ...
+          5. Let done be ? IteratorComplete(innerResult).
+          6. If done is true, then
+            a. Return ? IteratorValue(innerResult).
+          7. Let received be GeneratorYield(innerResult).
+      ...
+
+    %AsyncFromSyncIteratorPrototype%.throw ( value )
+
+    ...
+    5. Let throw be GetMethod(syncIterator, "throw").
+    ...
+    8. Let throwResult be Call(throw, syncIterator, « value »).
+    ...
+    11. Let throwValue be IteratorValue(throwResult).
+    ...
+    13. Let throwDone be IteratorComplete(throwResult).
+    ...
+    16. Perform ! Call(valueWrapperCapability.[[Resolve]], undefined,
+        « throwValue »).
+    ...
+    18. Set onFulfilled.[[Done]] to throwDone.
+    19. Perform ! PerformPromiseThen(valueWrapperCapability.[[Promise]],
+        onFulfilled, undefined, promiseCapability).
+    ...
+
+flags: [async]
+features: [async-iteration]
+---*/
+
+//- setup
+var log = [];
+var obj = {
+  [Symbol.iterator]() {
+    var throwCount = 0;
+    return {
+      name: "syncIterator",
+      get next() {
+        log.push({ name: "get next" });
+        return function() {
+          return {
+            value: "next-value-1",
+            done: false
+          };
+        };
+      },
+      get throw() {
+        log.push({
+          name: "get throw",
+          thisValue: this
+        });
+        return function() {
+          log.push({
+            name: "call throw",
+            thisValue: this,
+            args: [...arguments]
+          });
+
+          throwCount++;
+          if (throwCount == 1) {
+            return {
+              name: "throw-result-1",
+              get value() {
+                log.push({
+                  name: "get throw value (1)",
+                  thisValue: this
+                });
+                return "throw-value-1";
+              },
+              get done() {
+                log.push({
+                  name: "get throw done (1)",
+                  thisValue: this
+                });
+                return false;
+              }
+            };
+          }
+
+          return {
+            name: "throw-result-2",
+            get value() {
+              log.push({
+                name: "get throw value (2)",
+                thisValue: this
+              });
+              return "throw-value-2";
+            },
+            get done() {
+              log.push({
+                name: "get throw done (2)",
+                thisValue: this
+              });
+              return true;
+            }
+          };
+        };
+      }
+    };
+  }
+};
+
+//- body
+  log.push({ name: "before yield*" });
+  var v = yield* obj;
+  log.push({
+    name: "after yield*",
+    value: v
+  });
+  return "return-value";
+
+//- assertions
+assert.sameValue(log.length, 0, "log.length");
+
+iter.next().then(v => {
+  assert.sameValue(log[0].name, "before yield*");
+
+  assert.sameValue(log[1].name, "get next");
+
+  assert.sameValue(v.value, "next-value-1");
+  assert.sameValue(v.done, false);
+
+  assert.sameValue(log.length, 2, "log.length");
+
+  iter.throw("throw-arg-1").then(v => {
+    assert.sameValue(log[2].name, "get throw");
+    assert.sameValue(log[2].thisValue.name, "syncIterator", "get throw thisValue");
+
+    assert.sameValue(log[3].name, "call throw");
+    assert.sameValue(log[3].thisValue.name, "syncIterator", "throw thisValue");
+    assert.sameValue(log[3].args.length, 1, "throw args.length");
+    assert.sameValue(log[3].args[0], "throw-arg-1", "throw args[0]");
+
+    assert.sameValue(log[4].name, "get throw value (1)");
+    assert.sameValue(log[4].thisValue.name, "throw-result-1", "get throw value thisValue");
+
+    assert.sameValue(log[5].name, "get throw done (1)");
+    assert.sameValue(log[5].thisValue.name, "throw-result-1", "get throw done thisValue");
+
+    assert.sameValue(v.value, "throw-value-1");
+    assert.sameValue(v.done, false);
+
+    assert.sameValue(log.length, 6, "log.length");
+
+    iter.throw("throw-arg-2").then(v => {
+      assert.sameValue(log[6].name, "get throw");
+      assert.sameValue(log[6].thisValue.name, "syncIterator", "get throw thisValue");
+
+      assert.sameValue(log[7].name, "call throw");
+      assert.sameValue(log[7].thisValue.name, "syncIterator", "throw thisValue");
+      assert.sameValue(log[7].args.length, 1, "throw args.length");
+      assert.sameValue(log[7].args[0], "throw-arg-2", "throw args[0]");
+
+      assert.sameValue(log[8].name, "get throw value (2)");
+      assert.sameValue(log[8].thisValue.name, "throw-result-2", "get throw value thisValue");
+
+      assert.sameValue(log[9].name, "get throw done (2)");
+      assert.sameValue(log[9].thisValue.name, "throw-result-2", "get throw done thisValue");
+
+      assert.sameValue(log[10].name, "after yield*");
+      assert.sameValue(log[10].value, "throw-value-2");
+
+      assert.sameValue(v.value, "return-value");
+      assert.sameValue(v.done, true);
+
+      assert.sameValue(log.length, 11, "log.length");
+    }).then($DONE, $DONE);
+  }).catch($DONE);
+}).catch($DONE);