bugfix: add error handle to redis adapter to avoid unexpected exit.

lib/io.js

@@ -123,7 +123,12 @@ module.exports = app => {
   }
 
   if (config.redis) {
-    app.io.adapter(redis(config.redis));
+    const adapter = redis(config.redis);
+    // https://github.com/socketio/socket.io-redis/issues/21
+    adapter.prototype.on('error', err => {
+      app.coreLogger.error(err);
+    });
+    app.io.adapter(adapter);
     debug('[egg-socket.io] init socket.io-redis ready!');
   }
 

test/fixtures/apps/socket.io-test-redis-error/config/config.default.js

@@ -0,0 +1,10 @@
+'use strict';
+
+exports.io = {
+  redis: {
+    host: '127.0.0.1',
+    port: 6666,
+  },
+};
+
+exports.keys = '123';

test/fixtures/apps/socket.io-test-redis-error/package.json

@@ -0,0 +1,4 @@
+{
+  "name": "socket.io-test-redis-error",
+  "version": "0.0.1"
+}

test/io.test.js

@@ -487,6 +487,25 @@ describe('test/socketio.test.js', () => {
         }, 500);
       });
     }
+
+    it('redis connection error', done => {
+      const appName = 'socket.io-test-redis-error';
+      const app = mm.cluster({
+        baseDir: `apps/${appName}`,
+        workers: 2,
+        sticky: true,
+      });
+      app.ready().then(() => {
+        setTimeout(() => {
+          app.close()
+            .then(() => {
+              const errorLog = getErrorLogContent(appName);
+              assert(contains(errorLog, 'connect ECONNREFUSED 127.0.0.1:6666') > 0);
+            })
+            .then(done, done);
+        }, 300);
+      });
+    });
   });
 
   describe('namespace', () => {