Check mongodb version >=2.6.0 for aggregate queries (agenda#35)

README.md

@@ -34,6 +34,8 @@ A Dashboard for [Agenda](https://github.com/rschmukler/agenda)
 npm install --save agendash
 ```
 
+*Note*: `Agendash` requires mongodb version >2.6.0 to perform the needed aggregate queries. This is your mongo database version, not your node package version! To check your database version, connect to mongo and run `db.version()`.
+
 ### Standalone usage
 
 Agendash comes with a standalone Express app which you can use like this:

lib/agendash.js

@@ -1,5 +1,6 @@
 var async = require('async')
 var ObjectId = require('mongodb').ObjectId
+var semver = require('semver')
 
 module.exports = function (agenda, options) {
   options = options || {}
@@ -13,6 +14,11 @@ module.exports = function (agenda, options) {
         console.warn('Agendash indexes might not exist. Performance may decrease.')
       }
     })
+    agenda._mdb.admin().serverInfo().then(function (serverInfo) {
+      if (!semver.satisfies(serverInfo.version, '>=2.6.0')) {
+        console.warn('Agendash requires mongodb version >=2.6.0.')
+      }
+    })
   })
 
   return {

package.json

@@ -29,6 +29,7 @@
     "body-parser": "^1.15.0",
     "commander": "^2.9.0",
     "express": "^4.0.0",
-    "mongodb": "^2.0.0"
+    "mongodb": "^2.0.0",
+    "semver": "^5.3.0"
   }
 }

yarn.lock

@@ -407,7 +407,7 @@ resolve-from@^2.0.0:
   version "2.0.0"
   resolved "https://registry.yarnpkg.com/resolve-from/-/resolve-from-2.0.0.tgz#9480ab20e94ffa1d9e80a804c7ea147611966b57"
 
-semver@^5.1.0:
+semver@^5.1.0, semver@^5.3.0:
   version "5.3.0"
   resolved "https://registry.yarnpkg.com/semver/-/semver-5.3.0.tgz#9b2ce5d3de02d17c6012ad326aa6b4d0cf54f94f"