Record all gateways in ERC7786OpenBridge outbox

contracts/crosschain/ERC7786OpenBridge.sol

@@ -113,11 +113,9 @@ contract ERC7786OpenBridge is IERC7786GatewaySource, IERC7786Recipient, Ownable,
             address gateway = _gateways.at(i);
             // send message
             bytes32 id = IERC7786GatewaySource(gateway).sendMessage(bridge, wrappedPayload, attributes);
-            // if ID, track it
-            if (id != bytes32(0)) {
-                outbox[i] = Outbox(gateway, id);
-                needsId = true;
-            }
+            // fill outbox
+            outbox[i] = Outbox(gateway, id);
+            needsId = needsId || id != bytes32(0);
         }
 
         if (needsId) {

contracts/mocks/crosschain/ERC7786GatewayMock.sol

@@ -10,6 +10,12 @@ contract ERC7786GatewayMock is IERC7786GatewaySource {
     using BitMaps for BitMaps.BitMap;
     using InteroperableAddress for *;
 
+    bytes32 public sendId;
+
+    function setSendId(bytes32 _sendId) public {
+        sendId = _sendId;
+    }
+
     function supportsAttribute(bytes4 /*selector*/) public pure returns (bool) {
         return false;
     }
@@ -33,7 +39,7 @@ contract ERC7786GatewayMock is IERC7786GatewaySource {
             "Receiver error"
         );
 
-        emit MessageSent(0, sender, recipient, payload, 0, attributes);
-        return 0;
+        emit MessageSent(sendId, sender, recipient, payload, 0, attributes);
+        return sendId;
     }
 }

test/crosschain/ERC7786OpenBridge.test.js

@@ -2,8 +2,7 @@ const { ethers } = require('hardhat');
 const { expect } = require('chai');
 const { loadFixture } = require('@nomicfoundation/hardhat-network-helpers');
 const { anyValue } = require('@nomicfoundation/hardhat-chai-matchers/withArgs');
-
-const AxelarHelper = require('./axelar/AxelarHelper');
+const { getLocalChain } = require('@openzeppelin/contracts/test/helpers/chains');
 
 const getAddress = account => ethers.getAddress(account.target ?? account.address ?? account);
 
@@ -13,24 +12,15 @@ const M = 5;
 async function fixture() {
   const [owner, sender, ...accounts] = await ethers.getSigners();
 
+  const chain = await getLocalChain();
   const protocoles = await Promise.all(
     Array(M)
       .fill()
-      .map(() => AxelarHelper.deploy(owner)),
+      .map(() => ethers.deployContract('ERC7786GatewayMock')),
   );
 
-  const { chain } = protocoles.at(0);
-
-  const bridgeA = await ethers.deployContract('ERC7786OpenBridge', [
-    owner,
-    protocoles.map(({ gatewayA }) => gatewayA),
-    N,
-  ]);
-  const bridgeB = await ethers.deployContract('ERC7786OpenBridge', [
-    owner,
-    protocoles.map(({ gatewayB }) => gatewayB),
-    N,
-  ]);
+  const bridgeA = await ethers.deployContract('ERC7786OpenBridge', [owner, protocoles, N]);
+  const bridgeB = await ethers.deployContract('ERC7786OpenBridge', [owner, protocoles, N]);
   await bridgeA.registerRemoteBridge(chain.toErc7930(bridgeB));
   await bridgeB.registerRemoteBridge(chain.toErc7930(bridgeA));
 
@@ -43,17 +33,13 @@ describe('ERC7786OpenBridge', function () {
   });
 
   it('initial setup', async function () {
-    await expect(this.bridgeA.getGateways()).to.eventually.deep.equal(
-      this.protocoles.map(({ gatewayA }) => getAddress(gatewayA)),
-    );
+    await expect(this.bridgeA.getGateways()).to.eventually.deep.equal(this.protocoles.map(getAddress));
     await expect(this.bridgeA.getThreshold()).to.eventually.equal(N);
     await expect(this.bridgeA.getRemoteBridge(this.chain.erc7930)).to.eventually.equal(
       this.chain.toErc7930(this.bridgeB),
     );
 
-    await expect(this.bridgeB.getGateways()).to.eventually.deep.equal(
-      this.protocoles.map(({ gatewayB }) => getAddress(gatewayB)),
-    );
+    await expect(this.bridgeB.getGateways()).to.eventually.deep.equal(this.protocoles.map(getAddress));
     await expect(this.bridgeB.getThreshold()).to.eventually.equal(N);
     await expect(this.bridgeB.getRemoteBridge(this.chain.erc7930)).to.eventually.equal(
       this.chain.toErc7930(this.bridgeA),
@@ -136,9 +122,9 @@ describe('ERC7786OpenBridge', function () {
             );
 
           // MessagePosted to all gateways on the A side and received from all gateways on the B side
-          for (const { gatewayA, gatewayB } of this.protocoles) {
+          for (const gateway of this.protocoles) {
             await expect(txPromise)
-              .to.emit(gatewayA, 'MessageSent')
+              .to.emit(gateway, 'MessageSent')
               .withArgs(
                 ethers.ZeroHash,
                 this.chain.toErc7930(this.bridgeA),
@@ -148,7 +134,7 @@ describe('ERC7786OpenBridge', function () {
                 anyValue,
               )
               .to.emit(this.bridgeB, 'Received')
-              .withArgs(resultId, gatewayB);
+              .withArgs(resultId, gateway);
           }
 
           if (this.outcome) {
@@ -175,4 +161,50 @@ describe('ERC7786OpenBridge', function () {
       }
     });
   });
+
+  describe('outbox tracking', function () {
+    it('records every gateway in the outbox and emits OutboxDetails when a gateway returns a non-zero id', async function () {
+      const destination = await ethers.deployContract('$ERC7786RecipientMock', [this.bridgeB]);
+      const payload = ethers.randomBytes(128);
+      const attributes = [];
+
+      const outbox = this.protocoles.map(gateway => [gateway.target, ethers.ZeroHash]);
+      const id1 = (outbox[0][1] = ethers.hexlify(ethers.randomBytes(32)));
+      const id2 = (outbox[2][1] = ethers.hexlify(ethers.randomBytes(32)));
+
+      await this.protocoles[0].setSendId(id1);
+      await this.protocoles[2].setSendId(id2);
+
+      // The outbox lists all gateways, including the one that returned a zero id (with its address, not address(0))
+      const sendId = ethers.keccak256(ethers.AbiCoder.defaultAbiCoder().encode(['(address,bytes32)[]'], [outbox]));
+
+      await expect(
+        this.bridgeA.connect(this.sender).sendMessage(this.chain.toErc7930(destination), payload, attributes),
+      )
+        .to.emit(this.bridgeA, 'MessageSent')
+        .withArgs(sendId, this.chain.toErc7930(this.sender), this.chain.toErc7930(destination), payload, 0n, [])
+        .to.emit(this.bridgeA, 'OutboxDetails')
+        .withArgs(sendId, outbox);
+    });
+
+    it('does not emit OutboxDetails and keeps a zero sendId when all gateways return zero', async function () {
+      const destination = await ethers.deployContract('$ERC7786RecipientMock', [this.bridgeB]);
+      const payload = ethers.randomBytes(128);
+      const attributes = [];
+
+      await expect(
+        this.bridgeA.connect(this.sender).sendMessage(this.chain.toErc7930(destination), payload, attributes),
+      )
+        .to.emit(this.bridgeA, 'MessageSent')
+        .withArgs(
+          ethers.ZeroHash,
+          this.chain.toErc7930(this.sender),
+          this.chain.toErc7930(destination),
+          payload,
+          0n,
+          [],
+        )
+        .to.not.emit(this.bridgeA, 'OutboxDetails');
+    });
+  });
 });