refactory in-memory history into History object

lib/dashing.js

@@ -2,7 +2,8 @@ var fs = require('fs')
   , path = require('path')
   , express = require('express')
   , Mincer = require('mincer')
-  , coffee = require('coffee-script');
+  , coffee = require('coffee-script')
+  , InMemoryHistory = require('./inMemoryHistory');
 
 global.SCHEDULER = require('node-schedule');
 
@@ -79,7 +80,6 @@ module.exports.Dashing = function Dashing() {
   app.set('production', dashing.NODE_ENV === 'production');
 
   var connections = {};
-  var history = {};
 
   app.get('/events', dashing._protected, function(req, res) {
     // let request last as long as possible
@@ -178,7 +178,7 @@ module.exports.Dashing = function Dashing() {
     body.id = id;
     body.updatedAt = Date.now();
     var event = format_event(body);
-    history[id] = event;
+    dashing.history.record(id, event);
     for (var k in connections) {
       connections[k].send(event);
     }
@@ -191,9 +191,9 @@ module.exports.Dashing = function Dashing() {
 
   function latest_events() {
     var str = [];
-    for (var id in history) {
-      str.push(history[id]);
-    }
+    dashing.history.forEach( function(_id, data) {
+      str.push(data);
+    });
     return str.join('');
   }
 
@@ -241,6 +241,10 @@ module.exports.Dashing = function Dashing() {
     logger.info('Listening on http://0.0.0.0:' + dashing.port + (process.env.__daemon === 'false' ? ', CTRL+C to stop' : ''));
   }
 
+  dashing.useHistoryStore = function(store) {
+    dashing.history = store;
+  }
+
   dashing.start = function() {
     try {
       start_jobs();
@@ -250,6 +254,7 @@ module.exports.Dashing = function Dashing() {
       logger.error(e.toString()); // winston is not catching these?
     }
   }
+  dashing.useHistoryStore(new InMemoryHistory());
   dashing.app = app;
   return dashing;
 };

lib/inMemoryHistory.js

@@ -0,0 +1,24 @@
+var logger = require('./logger');
+
+var InMemoryHistory = module.exports = function() {
+  var self = this;
+
+  self._event_data = {};
+
+  self.record = function(id, body) {
+    self._event_data[id] = body;
+  };
+
+  self.last_by_id = function(id) {
+    return self._event_data[id];
+  };
+
+  self.forEach = function(func) {
+    var history = self._event_data;
+    for (var id in history) {
+      func(id, history[id]);
+    }
+  };
+
+  return self;
+};

test/history_test.js

@@ -0,0 +1,38 @@
+var should = require('should'),
+    History = require('../lib/history');
+
+describe('History', function() {
+  it('is a thing', function() {
+    should.exist(History); 
+  });
+
+  it('provides access to last record by id', function() {
+    var history = History.empty();
+
+    history.record('buzzwords', {
+      all_the_things: [ 1,2,3 ]
+    });
+
+    history.last_by_id('buzzwords')
+      .should.eql( {
+        all_the_things: [ 1,2,3]
+      });
+  });
+
+  it('can iterate latest event data',function() {
+    var history = History.empty();
+
+    history.record('buzzwords', { a: 1 });
+    history.record('builds', { time: 1.2 });
+
+    var found = { };
+    history.forEach( function(id, event) {
+      found[id] = event;
+    });
+
+    found.should.eql( {
+      'buzzwords': { a: 1},
+      'builds': { time: 1.2 }
+    });
+  });
+});