feat(ses): strip async generators for Hermes

- fix React Native Android release build (Metro bundle) error
- fix getAnonymousIntrinsics runtime SES error
- strip async generators and iterators
- strip related intrinsics (control abstraction objects)
- no longer attempt to repair them
- remove (and update) related tests
- before: 380 passed, 2 known failures, 2 skipped
- after: 379 passed, 2 known failures, 2 skipped

packages/ses/src/get-anonymous-intrinsics.js

@@ -95,20 +95,6 @@ export const getAnonymousIntrinsics = () => {
 
   const Generator = GeneratorFunction.prototype;
 
-  // 25.3.1 The AsyncGeneratorFunction Constructor
-
-  // eslint-disable-next-line no-empty-function
-  async function* AsyncGeneratorFunctionInstance() {}
-  const AsyncGeneratorFunction = getConstructorOf(
-    AsyncGeneratorFunctionInstance,
-  );
-
-  // 25.3.2.2 AsyncGeneratorFunction.prototype
-  const AsyncGenerator = AsyncGeneratorFunction.prototype;
-  // 25.5.1 Properties of the AsyncGenerator Prototype Object
-  const AsyncGeneratorPrototype = AsyncGenerator.prototype;
-  const AsyncIteratorPrototype = getPrototypeOf(AsyncGeneratorPrototype);
-
   // 25.7.1 The AsyncFunction Constructor
 
   // eslint-disable-next-line no-empty-function
@@ -119,10 +105,6 @@ export const getAnonymousIntrinsics = () => {
     '%InertFunction%': InertFunction,
     '%ArrayIteratorPrototype%': ArrayIteratorPrototype,
     '%InertAsyncFunction%': AsyncFunction,
-    '%AsyncGenerator%': AsyncGenerator,
-    '%InertAsyncGeneratorFunction%': AsyncGeneratorFunction,
-    '%AsyncGeneratorPrototype%': AsyncGeneratorPrototype,
-    '%AsyncIteratorPrototype%': AsyncIteratorPrototype,
     '%Generator%': Generator,
     '%InertGeneratorFunction%': GeneratorFunction,
     '%IteratorPrototype%': IteratorPrototype,

packages/ses/src/permits.js

@@ -1430,24 +1430,6 @@ export const permitted = {
     '@@toStringTag': 'string',
   },
 
-  '%InertAsyncGeneratorFunction%': {
-    // Properties of the AsyncGeneratorFunction Constructor
-    '[[Proto]]': '%InertFunction%',
-    prototype: '%AsyncGenerator%',
-  },
-
-  '%AsyncGenerator%': {
-    // Properties of the AsyncGeneratorFunction Prototype Object
-    '[[Proto]]': '%FunctionPrototype%',
-    constructor: '%InertAsyncGeneratorFunction%',
-    prototype: '%AsyncGeneratorPrototype%',
-    // length prop added here for React Native jsc-android
-    // https://github.com/endojs/endo/issues/660
-    // https://github.com/react-native-community/jsc-android-buildscripts/issues/181
-    length: 'number',
-    '@@toStringTag': 'string',
-  },
-
   '%GeneratorPrototype%': {
     // Properties of the Generator Prototype Object
     '[[Proto]]': '%IteratorPrototype%',
@@ -1458,16 +1440,6 @@ export const permitted = {
     '@@toStringTag': 'string',
   },
 
-  '%AsyncGeneratorPrototype%': {
-    // Properties of the AsyncGenerator Prototype Object
-    '[[Proto]]': '%AsyncIteratorPrototype%',
-    constructor: '%AsyncGenerator%',
-    next: fn,
-    return: fn,
-    throw: fn,
-    '@@toStringTag': 'string',
-  },
-
   // TODO: To be replaced with Promise.delegate
   //
   // The HandledPromise global variable shimmed by `@agoric/eventual-send/shim`

packages/ses/src/tame-function-constructors.js

@@ -121,16 +121,12 @@ export default function tameFunctionConstructors() {
     '%InertGeneratorFunction%',
     '(function*(){})',
   );
+  // Hermes doesn't support async arrow functions, is this ok?
   repairFunction(
     'AsyncFunction',
     '%InertAsyncFunction%',
     '(async function(){})',
   );
-  repairFunction(
-    'AsyncGeneratorFunction',
-    '%InertAsyncGeneratorFunction%',
-    '(async function*(){})',
-  );
 
   return newIntrinsics;
 }

packages/ses/test/harden.test.js

@@ -25,9 +25,6 @@ test('Compartment anonymous intrinsics are frozen', t => {
   t.throws(() => c.evaluate('(async function() {}).constructor.a = 10;'), {
     instanceOf: TypeError,
   });
-  t.throws(() => c.evaluate('(async function*() {}).constructor.a = 10;'), {
-    instanceOf: TypeError,
-  });
   t.throws(() => c.evaluate('(function*() {}).constructor.a = 10;'), {
     instanceOf: TypeError,
   });

packages/ses/test/ses.test.js

@@ -6,7 +6,7 @@ lockdown();
 /* eslint-disable no-proto, no-empty-function */
 
 test('tamed constructors', t => {
-  t.plan(12);
+  t.plan(10);
 
   function F() {}
   t.throws(() => F.__proto__.constructor(''), { instanceOf: TypeError });
@@ -17,9 +17,6 @@ test('tamed constructors', t => {
   function* G() {}
   t.throws(() => G.__proto__.constructor(''), { instanceOf: TypeError });
 
-  async function* AG() {}
-  t.throws(() => AG.__proto__.constructor(''), { instanceOf: TypeError });
-
   t.throws(() => Error.__proto__.constructor(''), { instanceOf: TypeError });
   t.throws(() => Function.prototype.constructor(''), { instanceOf: TypeError });
 
@@ -42,10 +39,6 @@ test('tamed constructors', t => {
   t.throws(() => c.evaluate("function* G() {}; G.__proto__.constructor('')"), {
     instanceOf: TypeError,
   });
-  t.throws(
-    () => c.evaluate("async function* AG() {}; AG.__proto__.constructor('')"),
-    { instanceOf: TypeError },
-  );
 });
 
 test('frozen', t => {

packages/ses/test/tame-function-unit.test.js

@@ -48,19 +48,3 @@ test('GeneratorFunction.constructor', t => {
     }
   }
 });
-
-test('AsyncGeneratorFunction.constructor', t => {
-  t.plan(1);
-
-  try {
-    // eslint-disable-next-line no-eval
-    const proto = Object.getPrototypeOf((0, eval)('(async function* () {})'));
-    t.throws(() => proto.constructor(''), { instanceOf: TypeError });
-  } catch (e) {
-    if (e instanceof SyntaxError) {
-      t.pass('not supported');
-    } else {
-      throw e;
-    }
-  }
-});