Instrument multiple versions of the same module (#397)

PR-URL: #397

test/hooks/test-hooks-multi-version.js

@@ -0,0 +1,75 @@
+/**
+ * Copyright 2017 Google Inc. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+'use strict';
+
+// Prereqs:
+// Start docker daemon
+//   ex) docker -d
+// Run a redis image binding the redis port
+//   ex) docker run -p 6379:6379 -d redis
+var assert = require('assert');
+var common = require('./common.js');
+
+describe('multiple instrumentations of the same module', function() {
+  var agent;
+  var clientv0;
+  var clientv2;
+
+  before(function() {
+    agent = require('../..').start({
+      enhancedDatabaseReporting: true,
+      samplingRate: 0
+    }).get();
+    clientv0 = require('./fixtures/redis0.12').createClient();
+    clientv0.on('error', function(err) {
+      assert(false, 'redisv0 error ' + err);
+    });
+    clientv2 = require('./fixtures/redis2.x').createClient();
+    clientv2.on('error', function(err) {
+      assert(false, 'redisv2 error ' + err);
+    });
+  });
+
+  after(function(done) {
+    clientv0.quit(function() {
+      clientv2.quit(function() {
+        done();
+      });
+    });
+  });
+
+  it('should record spans', function(done) {
+    common.runInTransaction(agent, function(endTransaction) {
+      clientv0.get('v0', function(err, n) {
+        clientv2.get('v2', function(err, n) {
+          endTransaction();
+          var spans = common.getMatchingSpans(agent, redisPredicate.bind(null, 'redis-get'));
+          assert.equal(spans.length, 2);
+          assert.equal(spans[0].labels.arguments, '["v0"]');
+          assert.equal(spans[0].labels.command, 'get');
+          assert.equal(spans[1].labels.arguments, '["v2"]');
+          assert.equal(spans[1].labels.command, 'get');
+          done();
+        });
+      });
+    });
+  });
+});
+
+function redisPredicate(id, span) {
+  return span.name.length >= id.length &&
+      span.name.substr(0, id.length) === id;
+}

test/test-plugin-loader.js

@@ -252,10 +252,6 @@ describe('Trace Plugin Loader', function() {
       'Files internal to a module are patched');
   });
 
-  // TODO(kjin): Add test to check that two modules with different versions
-  // can be loaded at the same time. Current test harness is insufficient for
-  // doing this.
-
   /**
    * Uses module interception to completely replace a module export
    */