add history service, with tests

src/kibana/components/history/history.js

@@ -0,0 +1,32 @@
+define(function (require) {
+  var modules = require('modules');
+  var _ = require('lodash');
+
+  modules.get('kibana/history')
+  .factory('history', function ($window, storage, config) {
+    function History(name, length) {
+      this.name = name;
+      this.maxLength = length || config.get('history:limit');
+      this.items = storage.get(this.name) || [];
+    }
+
+    History.prototype.add = function (val) {
+      if (!val) {
+        return this.items;
+      }
+
+      var history = _.pull(this.items.slice(0), val);
+      history.unshift(val);
+
+      this.items = history.slice(0, this.maxLength);
+      storage.set(this.name, this.items);
+      return this.items;
+    };
+
+    History.prototype.get = function () {
+      return this.items;
+    };
+
+    return History;
+  });
+});

test/unit/specs/services/history.js

@@ -0,0 +1,95 @@
+define(function (require) {
+  var sinon = require('sinon/sinon');
+
+  var storage;
+  var config;
+  var history;
+
+  var historyName = 'testHistory';
+  var historyLimit = 10;
+  var payload = [
+    { first: 'clark', last: 'kent' },
+    { first: 'peter', last: 'parker' },
+    { first: 'bruce', last: 'wayne' }
+  ];
+
+  require('components/history/history');
+
+  function init() {
+    module('kibana/history', function ($provide) {
+      // mock storage service
+      $provide.service('storage', function () {
+        this.get = sinon.stub();
+        this.set = sinon.stub();
+        this.remove = sinon.spy();
+        this.clear = sinon.spy();
+      });
+
+      // mock config service
+      $provide.service('config', function () {
+        this.get = sinon.stub().returns(historyLimit);
+      });
+    });
+
+    inject(function ($injector) {
+      storage = $injector.get('storage');
+      config = $injector.get('config');
+      history = $injector.get('history');
+    });
+  }
+
+  describe.only('HistoryFactory', function () {
+    beforeEach(function () {
+      init();
+    });
+
+    describe('expected API', function () {
+      it('has expected methods', function () {
+        var h = new history(historyName);
+
+        expect(h.add).to.be.a('function');
+        expect(h.get).to.be.a('function');
+      });
+    });
+
+    describe('internal functionality', function () {
+      it('reads from storage', function () {
+        var h = new history(historyName);
+
+        expect(storage.get.calledOnce).to.be(true);
+        expect(storage.get.calledWith(historyName)).to.be(true);
+      });
+
+      it('writes to storage', function () {
+        var h = new history(historyName);
+        var newItem = { first: 'diana', last: 'prince' };
+
+        var data = h.add(newItem);
+
+        expect(storage.set.calledOnce).to.be(true);
+        expect(data).to.eql([newItem]);
+      });
+    });
+
+    describe('persisting data', function () {
+      it('fetches records from storage', function () {
+        storage.get.returns(payload);
+        var h = new history(historyName);
+
+        var items = h.get();
+        expect(items.length).to.equal(3);
+        expect(items).to.eql(payload);
+      });
+
+      it('prepends new records', function () {
+        storage.get.returns(payload);
+        var h = new history(historyName);
+        var newItem = { first: 'selina', last: 'kyle' };
+
+        var items = h.add(newItem);
+        expect(items.length).to.equal(4);
+        expect(items[0]).to.eql(newItem);
+      });
+    });
+  });
+});