feat(op-msg): add support for OP_MSG to command monitoring

lib/connection/apm.js

@@ -1,5 +1,6 @@
 'use strict';
-const Query = require('../connection/commands').Query;
+// const Query = require('../connection/commands').Query;
+const Msg = require('../connection/msg').Msg;
 const KillCursor = require('../connection/commands').KillCursor;
 const GetMore = require('../connection/commands').GetMore;
 const calculateDurationInMs = require('../utils').calculateDurationInMs;
@@ -18,7 +19,7 @@ const SENSITIVE_COMMANDS = new Set([
 ]);
 
 // helper methods
-const extractCommandName = command => Object.keys(command)[0];
+const extractCommandName = commandDoc => Object.keys(commandDoc)[0];
 const namespace = command => command.ns;
 const databaseName = command => command.ns.split('.')[0];
 const collectionName = command => command.ns.split('.')[1];
@@ -76,41 +77,44 @@ const extractCommand = command => {
     };
   }
 
-  command = command instanceof Query ? command.query : command.command;
-  if (command.$query == null) {
-    return command;
+  if (command instanceof Msg) {
+    return command.command;
   }
 
-  let result;
-  if (command.ns === 'admin.$cmd') {
-    // upconvert legacy command
-    result = Object.assign({}, command.query.$query);
-  } else {
-    // upconvert legacy find command
-    result = { find: collectionName(command) };
-    Object.keys(LEGACY_FIND_QUERY_MAP).forEach(key => {
-      if (typeof command.query[key] !== 'undefined')
-        result[LEGACY_FIND_QUERY_MAP[key]] = command.query[key];
+  if (command.query && command.query.$query) {
+    let result;
+    if (command.ns === 'admin.$cmd') {
+      // upconvert legacy command
+      result = Object.assign({}, command.query.$query);
+    } else {
+      // upconvert legacy find command
+      result = { find: collectionName(command) };
+      Object.keys(LEGACY_FIND_QUERY_MAP).forEach(key => {
+        if (typeof command.query[key] !== 'undefined')
+          result[LEGACY_FIND_QUERY_MAP[key]] = command.query[key];
+      });
+    }
+
+    Object.keys(LEGACY_FIND_OPTIONS_MAP).forEach(key => {
+      if (typeof command[key] !== 'undefined') result[LEGACY_FIND_OPTIONS_MAP[key]] = command[key];
     });
-  }
 
-  Object.keys(LEGACY_FIND_OPTIONS_MAP).forEach(key => {
-    if (typeof command[key] !== 'undefined') result[LEGACY_FIND_OPTIONS_MAP[key]] = command[key];
-  });
+    OP_QUERY_KEYS.forEach(key => {
+      if (command[key]) result[key] = command[key];
+    });
 
-  OP_QUERY_KEYS.forEach(key => {
-    if (command[key]) result[key] = command[key];
-  });
+    if (typeof command.pre32Limit !== 'undefined') {
+      result.limit = command.pre32Limit;
+    }
 
-  if (typeof command.pre32Limit !== 'undefined') {
-    result.limit = command.pre32Limit;
-  }
+    if (command.query.$explain) {
+      return { explain: result };
+    }
 
-  if (command.query.$explain) {
-    return { explain: result };
+    return result;
   }
 
-  return result;
+  return command.query ? command.query : command;
 };
 
 const extractReply = (command, reply) => {