[FAB-16602] Fix Node.js chaincode event publishing

The event name was being sent in snake_case, not in
camelCase, so it was being ignored. This change was
incorrectly made recently (by me!) when migrating to
the new protobufjs library.

There are no tests that check chaincode events work,
so I've added a test at the same time so nobody can
do this in the future.

Signed-off-by: Simon Stone <sstone1@uk.ibm.com>
Change-Id: Ia202c59065587f9bcf36b02c2770f591e8a5c988

Author: Simon Stone

fabric-shim/lib/stub.js

@@ -734,8 +734,11 @@ class ChaincodeStub {
             throw new Error('Event name must be a non-empty string');
         }
 
+        // Because this is passed directly into gRPC as an object, rather
+        // than a serialized protocol buffer message, it uses snake_case
+        // rather than camelCase like the rest of the code base.
         this.chaincodeEvent = {
-            eventName: name,
+            event_name: name,
             payload
         };
     }

fabric-shim/test/unit/stub.js

@@ -939,7 +939,7 @@ describe('Stub', () => {
 
             it ('should set an event', () => {
                 stub.setEvent('some name', Buffer.from('some payload'));
-                expect(stub.chaincodeEvent.eventName).to.equal('some name');
+                expect(stub.chaincodeEvent.event_name).to.equal('some name');
                 expect(stub.chaincodeEvent.payload).to.deep.equal(Buffer.from('some payload'));
             });
         });

test/fv/events.js

@@ -0,0 +1,42 @@
+/*
+# Copyright IBM Corp. All Rights Reserved.
+#
+# SPDX-License-Identifier: Apache-2.0
+*/
+'use strict';
+
+const chai = require('chai');
+chai.use(require('chai-as-promised'));
+const expect = chai.expect;
+const utils = require('./utils');
+const {LONG_STEP} = utils.TIMEOUTS;
+
+describe('Chaincode events', async function () {
+    const suite = 'events';
+
+    before(async function () {
+        this.timeout(LONG_STEP);
+
+        return utils.installAndInstantiate(suite, 'org.mynamespace.events:instantiate');
+    });
+
+    it('should publish an event', async function () {
+        this.timeout(LONG_STEP);
+
+        const date = new Date().toISOString();
+        await utils.invoke(suite, 'org.mynamespace.events:emit', [`my event data @ ${date}`]);
+        const block = await utils.getLastBlock();
+        expect(block.data.data.length).to.equal(1); // only one transaction
+        const transaction = block.data.data[0];
+        const actions = transaction.payload.data.actions;
+        expect(actions.length).to.equal(1); // only one action
+        const action = actions[0];
+        const proposalResponsePayload = action.payload.action.proposal_response_payload;
+        const events = proposalResponsePayload.extension.events;
+        expect(events.chaincode_id).to.equal('events');
+        expect(events.event_name).to.equal('myevent');
+        const payload = Buffer.from(events.payload, 'base64').toString();
+        expect(payload).to.equal(`my event data @ ${date}`);
+    });
+
+});

test/fv/events/chaincode.js

@@ -0,0 +1,27 @@
+/*
+# Copyright IBM Corp. All Rights Reserved.
+#
+# SPDX-License-Identifier: Apache-2.0
+*/
+'use strict';
+
+const {Contract} = require('fabric-contract-api');
+
+class EventsChaincode extends Contract {
+
+    constructor() {
+        super('org.mynamespace.events');
+        this.logBuffer = {output: []};
+    }
+
+    async instantiate(ctx) {
+
+    }
+
+    async emit(ctx, value) {
+        const buffer = Buffer.from(value);
+        ctx.stub.setEvent('myevent', buffer);
+    }
+
+}
+module.exports = EventsChaincode;

test/fv/events/index.js

@@ -0,0 +1,5 @@
+'use strict';
+
+const Chaincode = require('./chaincode');
+
+module.exports.contracts = [Chaincode];

test/fv/events/package.json

@@ -0,0 +1,21 @@
+{
+  "name": "chaincode",
+  "description": "Chaincode testing events functionality",
+  "engines": {
+    "node": ">=8.4.0",
+    "npm": ">=5.3.0"
+  },
+  "scripts": {
+    "start": "fabric-chaincode-node start"
+  },
+  "main": "index.js",
+  "engine-strict": true,
+  "engineStrict": true,
+  "version": "1.0.0",
+  "author": "",
+  "license": "Apache-2.0",
+  "dependencies": {
+    "fabric-shim": "unstable",
+    "fabric-contract-api": "unstable"
+  }
+}

test/fv/utils.js

@@ -87,6 +87,15 @@ async function installAndInstantiate(ccName, instantiateFunc, instantiateArgs) {
     return instantiate(ccName, instantiateFunc, instantiateArgs);
 }
 
+async function getLastBlock() {
+    const cmd = 'docker exec org1_cli bash -c "peer channel fetch newest -c mychannel /tmp/mychannel.block && configtxlator proto_decode --type common.Block --input=/tmp/mychannel.block"';
+    const {error, stdout, stderr} = await exec(cmd);
+    if (error) {
+        throw new Error(error, stderr);
+    }
+    return JSON.parse(stdout.trim());
+}
+
 const TIMEOUTS = {
     LONGEST_STEP : 24000 * 1000 * multiplier,
     LONG_STEP : 240 * 1000 * multiplier,
@@ -96,4 +105,4 @@ const TIMEOUTS = {
     MED_INC : 10 * 1000 * multiplier,
     SHORT_INC: 5 * 1000 * multiplier
 };
-module.exports = {installAndInstantiate, invoke, query, TIMEOUTS};
+module.exports = {installAndInstantiate, invoke, query, getLastBlock, TIMEOUTS};