feat: bidirectional loopback with makeNear

packages/captp/lib/captp.js

@@ -370,42 +370,52 @@ export function makeCapTP(ourId, rawSend, bootstrapObj = undefined, opts = {}) {
  * Create an async-isolated channel to an object.
  *
  * @param {string} ourId
- * @returns {{ makeFar<T>(x: T): ERef<T> }}
+zcf * @returns {{ makeFar<T>(x: T): ERef<T>, makeNear<T>(x: T): ERef<T>  }}
  */
 export function makeLoopback(ourId) {
   let nextNonce = 0;
   const nonceToRef = new Map();
 
+  const bootstrap = harden({
+    refGetter: {
+      getRef(nonce) {
+        // Find the local ref for the specified nonce.
+        const xFar = nonceToRef.get(nonce);
+        nonceToRef.delete(nonce);
+        return xFar;
+      },
+    },
+  });
+
   // Create the tunnel.
   let remoteDispatch;
-  const { dispatch: localDispatch, getBootstrap } = makeCapTP(
+  const { dispatch: localDispatch, getBootstrap: getFarBootstrap } = makeCapTP(
     `local-${ourId}`,
     o => remoteDispatch(o),
+    bootstrap,
   );
-  const { dispatch } = makeCapTP(
+  const { dispatch, getBootstrap: getNearBootstrap } = makeCapTP(
     `remote-${ourId}`,
     localDispatch,
-    harden({
-      farGetter: {
-        getRef(nonce) {
-          // Find the local ref for the specified nonce.
-          const xNear = nonceToRef.get(nonce);
-          nonceToRef.delete(nonce);
-          return xNear;
-        },
-      },
-    }),
+    bootstrap,
   );
   remoteDispatch = dispatch;
 
-  const farGetter = E.G(getBootstrap()).farGetter;
+  const farGetter = E.G(getFarBootstrap()).refGetter;
+  const nearGetter = E.G(getNearBootstrap()).refGetter;
 
   async function makeFar(xNear) {
     const myNonce = nextNonce;
     nextNonce += 1;
     nonceToRef.set(myNonce, harden(xNear));
     return E(farGetter).getRef(myNonce);
   }
+  async function makeNear(xFar) {
+    const myNonce = nextNonce;
+    nextNonce += 1;
+    nonceToRef.set(myNonce, harden(xFar));
+    return E(nearGetter).getRef(myNonce);
+  }
 
-  return { makeFar };
+  return { makeFar, makeNear };
 }