add deflate option assertion

graylog.js

@@ -2,7 +2,8 @@ var zlib         = require('zlib'),
     crypto       = require('crypto'),
     dgram        = require('dgram'),
     util         = require('util'),
-    EventEmitter = require('events').EventEmitter;
+    EventEmitter = require('events').EventEmitter,
+    assert       = require('assert');
 
 /**
  * Graylog instances emit errors. That means you really really should listen for them,
@@ -19,6 +20,9 @@ var graylog = function graylog(config) {
     this.hostname     = config.hostname || require('os').hostname();
     this.facility     = config.facility || 'Node.js';
     this.deflate      = config.deflate || 'optimal';
+    assert(
+      this.deflate === 'optimal' || this.deflate === 'always' || this.deflate === 'never',
+      'deflate must be one of "optimal", "always", or "never". was "' + this.deflate + '"');
 
     this._unsentMessages = 0;
     this._unsentChunks = 0;

test.js

@@ -1,5 +1,6 @@
 var graylog = require('./graylog'),
     fs      = require('fs'),
+    assert  = require('assert'),
     file,
     data,
     servers = [
@@ -66,3 +67,19 @@ client.close(function () {
     console.log('Insertion complete. Please check', 'http://' + servers[0].host + ':3000', 'and verify that insertion was successfull');
     console.log('');
 });
+
+console.log('---------------------------------------------');
+console.log('Checking deflate assertion');
+console.log('---------------------------------------------');
+try {
+  new graylog.graylog({
+      servers: servers,
+      facility: 'Test logger / Node.JS Test Script',
+      deflate: 'not an option'
+  });
+  throw new Error('should not get here')
+} catch (err) {
+  assert(
+    err.message === 'deflate must be one of "optimal", "always", or "never". was "not an option"',
+    'assertion msg was wrong: ' + err.message);
+}