feat(asyncFlow): Stopgap E support

packages/async-flow/src/replay-membrane.js

@@ -1,16 +1,26 @@
 /* eslint-disable no-use-before-define */
 import { Fail, X, b, makeError, q } from '@endo/errors';
-import { isPromise } from '@endo/promise-kit';
-import { Far, Remotable, getInterfaceOf } from '@endo/pass-style';
+import {
+  Far,
+  Remotable,
+  getInterfaceOf,
+  getTag,
+  makeTagged,
+  passStyleOf,
+} from '@endo/pass-style';
 import { E } from '@endo/eventual-send';
+import { throwLabeled } from '@endo/common/throw-labeled.js';
+import { heapVowE } from '@agoric/vow/vat.js';
 import { getMethodNames } from '@endo/eventual-send/utils.js';
+import { objectMap } from '@endo/common/object-map.js';
 import { isVow } from '@agoric/vow/src/vow-utils.js';
 import { makeEquate } from './equate.js';
 import { makeConvertKit } from './convert.js';
 
 /**
  * @import {PromiseKit} from '@endo/promise-kit'
- * @import {Vow, VowTools} from '@agoric/vow'
+ * @import {Passable, PassableCap, CopyTagged} from '@endo/pass-style'
+ * @import {Vow, VowTools, VowKit} from '@agoric/vow'
  * @import {LogStore} from '../src/log-store.js';
  * @import {Bijection} from '../src/bijection.js';
  * @import {Host, HostVow, LogEntry, Outcome} from '../src/types.js';
@@ -33,7 +43,7 @@ export const makeReplayMembrane = ({
   watchWake,
   panic,
 }) => {
-  const { when, watch } = vowTools;
+  const { when, watch, makeVowKit } = vowTools;
 
   const equate = makeEquate(bijection);
 
@@ -127,18 +137,50 @@ export const makeReplayMembrane = ({
 
   // ///////////// Guest to Host or consume log ////////////////////////////////
 
+  /**
+   * The host is not supposed to expose host-side promises to the membrane,
+   * since they cannot be stored durably or survive upgrade. We cannot just
+   * automatically wrap any such host promises with host vows, because that
+   * would mask upgrade hazards if an upgrade happens before the vow settles.
+   * However, during the transition, the current host APIs called by
+   * orchestration still return many promises. We want to generate diagnostics
+   * when we encounter them, but for now, automatically convert them to
+   * host vow anyway, just so integration testing can proceed to reveal
+   * additional problems beyond these.
+   *
+   * @param {Passable} h
+   */
   const tolerateHostPromiseToVow = h => {
-    if (isPromise(h)) {
-      const e = Error('where warning happened');
-      console.log('Warning for now: vow expected, not promise', h, e);
-      // TODO remove this stopgap. Here for now because host-side
-      // promises are everywhere!
-      // Note: A good place to set a breakpoint, or to uncomment the
-      // `debugger;` line, to work around bundling.
-      // debugger;
-      return watch(h);
-    } else {
-      return h;
+    const passStyle = passStyleOf(h);
+    switch (passStyle) {
+      case 'promise': {
+        const e = Error('where warning happened');
+        console.log('Warning for now: vow expected, not promise', h, e);
+        // TODO remove this stopgap. Here for now because host-side
+        // promises are everywhere!
+        // Note: A good place to set a breakpoint, or to uncomment the
+        // `debugger;` line, to work around bundling.
+        // debugger;
+        return watch(h);
+      }
+      case 'copyRecord': {
+        const o = /** @type {object} */ (h);
+        return objectMap(o, tolerateHostPromiseToVow);
+      }
+      case 'copyArray': {
+        const a = /** @type {Array} */ (h);
+        return harden(a.map(tolerateHostPromiseToVow));
+      }
+      case 'tagged': {
+        const t = /** @type {CopyTagged} */ (h);
+        if (isVow(t)) {
+          return h;
+        }
+        return makeTagged(getTag(t), tolerateHostPromiseToVow(t.payload));
+      }
+      default: {
+        return h;
+      }
     }
   };
 
@@ -150,6 +192,7 @@ export const makeReplayMembrane = ({
         : hostTarget(...hostArgs);
       // This is a temporary kludge anyway. But note that it only
       // catches the case where the promise is at the top of hostResult.
+      harden(hostResult);
       hostResult = tolerateHostPromiseToVow(hostResult);
       // Try converting here just to route the error correctly
       hostToGuest(hostResult, `converting ${optVerb || 'host'} result`);
@@ -233,12 +276,123 @@ export const makeReplayMembrane = ({
 
   // //////////////// Eventual Send ////////////////////////////////////////////
 
+  /**
+   * @param {PassableCap} hostTarget
+   * @param {string | undefined} optVerb
+   * @param {Passable[]} hostArgs
+   * @param {number} callIndex
+   * @param {VowKit} hostResultKit
+   * @param {Promise} guestReturnedP
+   * @returns {Outcome}
+   */
+  const performSend = (
+    hostTarget,
+    optVerb,
+    hostArgs,
+    callIndex,
+    hostResultKit,
+    guestReturnedP,
+  ) => {
+    const { vow, resolver } = hostResultKit;
+    try {
+      const hostPromise = optVerb
+        ? heapVowE(hostTarget)[optVerb](...hostArgs)
+        : // eslint-disable-next-line @typescript-eslint/prefer-ts-expect-error
+          // @ts-ignore once we changed this from E to heapVowE,
+          // typescript started complaining that heapVowE(hostTarget)
+          // is not callable. I'm not sure if this is a just a typing bug
+          // in heapVowE or also reflects a runtime deficiency. But this
+          // case it not used yet anyway. We disable it
+          // with at-ts-ignore rather than at-ts-expect-error because
+          // the dependency-graph tests complains that the latter is unused.
+          heapVowE(hostTarget)(...hostArgs);
+      resolver.resolve(hostPromise); // TODO does this always work?
+    } catch (hostProblem) {
+      throw Panic`internal: eventual send synchrously failed ${hostProblem}`;
+    }
+    try {
+      const entry = harden(['doReturn', callIndex, vow]);
+      log.pushEntry(entry);
+      const guestPromise = makeGuestForHostVow(vow, guestReturnedP);
+      // Note that `guestPromise` is not registered in the bijection since
+      // guestReturnedP is already the guest for vow. Rather, the handler
+      // returns guestPromise to resolve guestReturnedP to guestPromise.
+      doReturn(callIndex, vow);
+      return harden({
+        kind: 'return',
+        result: guestPromise,
+      });
+    } catch (problem) {
+      throw panic(problem);
+    }
+  };
+
   const guestHandler = harden({
     applyMethod(guestTarget, optVerb, guestArgs, guestReturnedP) {
-      if (optVerb === undefined) {
-        throw Panic`guest eventual call not yet supported: ${guestTarget}(${b(guestArgs)}) -> ${b(guestReturnedP)}`;
-      } else {
-        throw Panic`guest eventual send not yet supported: ${guestTarget}.${b(optVerb)}(${b(guestArgs)}) -> ${b(guestReturnedP)}`;
+      const callIndex = log.getIndex();
+      if (stopped || !bijection.hasGuest(guestTarget)) {
+        Fail`Sent from a previous run: ${guestTarget}`;
+      }
+      const hostResultKit = makeVowKit();
+      const g = bijection.unwrapInit(guestReturnedP, hostResultKit.vow);
+      g === guestReturnedP ||
+        Fail`internal: guestReturnedP should not unwrap: ${g} vs ${guestReturnedP}`;
+      /** @type {Outcome} */
+      let outcome;
+      try {
+        const guestEntry = harden([
+          'checkSend',
+          guestTarget,
+          optVerb,
+          guestArgs,
+          callIndex,
+        ]);
+        if (log.isReplaying()) {
+          const entry = log.nextEntry();
+          try {
+            equate(guestEntry, entry);
+          } catch (equateErr) {
+            // TODO consider Richard Gibson's suggestion for a better way
+            // to keep track of the error labeling.
+            throwLabeled(
+              equateErr,
+              `replay ${callIndex}:
+     ${q(guestEntry)}
+  vs ${q(entry)}
+    `,
+            );
+          }
+          outcome = /** @type {Outcome} */ (nestInterpreter(callIndex));
+        } else {
+          const entry = guestToHost(guestEntry);
+          log.pushEntry(entry);
+          const [_op, hostTarget, _optVerb, hostArgs, _callIndex] = entry;
+          nestInterpreter(callIndex);
+          outcome = performSend(
+            hostTarget,
+            optVerb,
+            hostArgs,
+            callIndex,
+            hostResultKit,
+            guestReturnedP,
+          );
+        }
+      } catch (fatalError) {
+        throw panic(fatalError);
+      }
+
+      switch (outcome.kind) {
+        case 'return': {
+          return outcome.result;
+        }
+        case 'throw': {
+          throw outcome.problem;
+        }
+        default: {
+          // @ts-expect-error TS correctly knows this case would be outside
+          // the type. But that's what we want to check.
+          throw Panic`unexpected outcome kind ${q(outcome.kind)}`;
+        }
       }
     },
     applyFunction(guestTarget, guestArgs, guestReturnedP) {
@@ -340,13 +494,21 @@ export const makeReplayMembrane = ({
 
   /**
    * @param {Vow} hVow
-   * @returns {unknown}
+   * @param {Promise} [promiseKey]
+   *   If provided, use this promise as the key in the guestPromiseMap
+   *   rather than the returned promise. This only happens when the
+   *   promiseKey ends up forwarded to the returned promise anyway, so
+   *   associating it with this resolve/reject pair is not incorrect.
+   *   It is needed when `promiseKey` is also entered into the bijection
+   *   paired with hVow.
+   * @returns {Promise}
    */
-  const makeGuestForHostVow = hVow => {
+  const makeGuestForHostVow = (hVow, promiseKey = undefined) => {
     hVow = tolerateHostPromiseToVow(hVow);
     isVow(hVow) || Fail`vow expected ${hVow}`;
     const { promise, resolve, reject } = makeGuestPromiseKit();
-    guestPromiseMap.set(promise, harden({ resolve, reject }));
+    promiseKey ??= promise;
+    guestPromiseMap.set(promiseKey, harden({ resolve, reject }));
 
     watchWake(hVow);
 
@@ -370,7 +532,7 @@ export const makeReplayMembrane = ({
       hVow,
       async hostFulfillment => {
         await log.promiseReplayDone(); // should never reject
-        if (!stopped && guestPromiseMap.get(promise) !== 'settled') {
+        if (!stopped && guestPromiseMap.get(promiseKey) !== 'settled') {
           /** @type {LogEntry} */
           const entry = harden(['doFulfill', hVow, hostFulfillment]);
           log.pushEntry(entry);
@@ -385,7 +547,7 @@ export const makeReplayMembrane = ({
       },
       async hostReason => {
         await log.promiseReplayDone(); // should never reject
-        if (!stopped && guestPromiseMap.get(promise) !== 'settled') {
+        if (!stopped && guestPromiseMap.get(promiseKey) !== 'settled') {
           /** @type {LogEntry} */
           const entry = harden(['doReject', hVow, hostReason]);
           log.pushEntry(entry);

packages/async-flow/src/type-guards.js

@@ -42,13 +42,13 @@ export const LogEntryShape = M.or(
     M.arrayOf(M.any()),
     M.number(),
   ],
-  // [
-  //   'checkSend',
-  //   M.or(M.remotable('host target'), VowShape),
-  //   M.opt(PropertyKeyShape),
-  //   M.arrayOf(M.any()),
-  //   M.number(),
-  // ],
+  [
+    'checkSend',
+    M.or(M.remotable('host target'), VowShape),
+    M.opt(PropertyKeyShape),
+    M.arrayOf(M.any()),
+    M.number(),
+  ],
   // ['checkReturn', M.number(), M.any()],
   // ['checkThrow', M.number(), M.any()],
 );

packages/async-flow/src/types.js

@@ -103,6 +103,12 @@ export {};
  *     optVerb: PropertyKey|undefined,
  *     args: Host[],
  *     callIndex: number
+ *   ] | [
+ *     op: 'checkSend',
+ *     target: Host,
+ *     optVerb: PropertyKey|undefined,
+ *     args: Host[],
+ *     callIndex: number
  *   ]} LogEntry
  */
 

packages/async-flow/test/bad-host.test.js

@@ -141,7 +141,7 @@ const testBadHostReplay1 = async (t, zone) => {
         },
         {
           message:
-            'converting badMethod result: Remotables must be explicitly declared: "[Function nonPassableFunc]"',
+            'Remotables must be explicitly declared: "[Function nonPassableFunc]"',
         },
       );
       t.log('  badHost replay1 guest error caused by host error', gErr);
@@ -177,7 +177,7 @@ const testBadHostReplay1 = async (t, zone) => {
       'doThrow',
       2,
       Error(
-        'converting badMethod result: Remotables must be explicitly declared: "[Function nonPassableFunc]"',
+        'Remotables must be explicitly declared: "[Function nonPassableFunc]"',
       ),
     ],
     ['checkCall', badHost, 'badMethod', [], 4],