diff --git a/js/common/util/can_toggle_domain.js b/js/common/util/can_toggle_domain.js
new file mode 100644
index 0000000000..48e41e8297
--- /dev/null
+++ b/js/common/util/can_toggle_domain.js
@@ -0,0 +1,11 @@
+export default function canToggleDomain(hass, domain) {
+  const services = hass.config.services[domain];
+  if (!services) { return false; }
+
+  if (domain === 'lock') {
+    return 'lock' in services;
+  } else if (domain === 'cover') {
+    return 'open_cover' in services;
+  }
+  return 'turn_on' in services;
+}
diff --git a/js/common/util/can_toggle_state.js b/js/common/util/can_toggle_state.js
new file mode 100644
index 0000000000..c7859cedc5
--- /dev/null
+++ b/js/common/util/can_toggle_state.js
@@ -0,0 +1,11 @@
+import canToggleDomain from './can_toggle_domain.js';
+import computeStateDomain from './compute_state_domain.js';
+
+export default function canToggleState(hass, stateObj) {
+  const domain = computeStateDomain(stateObj);
+  if (domain === 'group') {
+    return stateObj.state === 'on' || stateObj.state === 'off';
+  }
+
+  return canToggleDomain(hass, domain);
+}
diff --git a/js/common/util/feature_class_names.js b/js/common/util/feature_class_names.js
new file mode 100644
index 0000000000..73262ab06b
--- /dev/null
+++ b/js/common/util/feature_class_names.js
@@ -0,0 +1,10 @@
+// Expects classNames to be an object mapping feature-bit -> className
+export default function featureClassNames(stateObj, classNames) {
+  if (!stateObj || !stateObj.attributes.supported_features) return '';
+
+  const features = stateObj.attributes.supported_features;
+
+  return Object.keys(classNames).map(feature => (
+    (features & feature) !== 0 ? classNames[feature] : ''
+  )).filter(attr => attr !== '').join(' ');
+}
diff --git a/js/common/util/state_card_type.js b/js/common/util/state_card_type.js
new file mode 100644
index 0000000000..73d2378f2a
--- /dev/null
+++ b/js/common/util/state_card_type.js
@@ -0,0 +1,31 @@
+import canToggleState from './can_toggle_state.js';
+import computeStateDomain from './compute_state_domain.js';
+
+const DOMAINS_WITH_CARD = [
+  'climate',
+  'cover',
+  'configurator',
+  'input_select',
+  'input_number',
+  'input_text',
+  'media_player',
+  'scene',
+  'script',
+  'weblink',
+];
+
+export default function stateCardType(hass, stateObj) {
+  if (stateObj.state === 'unavailable') {
+    return 'display';
+  }
+
+  const domain = computeStateDomain(stateObj);
+
+  if (DOMAINS_WITH_CARD.includes(domain)) {
+    return domain;
+  } else if (canToggleState(hass, stateObj) &&
+             stateObj.attributes.control !== 'hidden') {
+    return 'toggle';
+  }
+  return 'display';
+}
diff --git a/js/common/util/state_more_info_type.js b/js/common/util/state_more_info_type.js
new file mode 100644
index 0000000000..ddd7aaad96
--- /dev/null
+++ b/js/common/util/state_more_info_type.js
@@ -0,0 +1,23 @@
+import computeStateDomain from './compute_state_domain.js';
+
+const DOMAINS_WITH_MORE_INFO = [
+  'alarm_control_panel', 'automation', 'camera', 'climate', 'configurator',
+  'cover', 'fan', 'group', 'history_graph', 'light', 'lock', 'media_player', 'script',
+  'sun', 'updater', 'vacuum', 'input_datetime',
+];
+
+const HIDE_MORE_INFO = [
+  'input_select', 'scene', 'input_number', 'input_text'
+];
+
+export default function stateMoreInfoType(stateObj) {
+  const domain = computeStateDomain(stateObj);
+
+  if (DOMAINS_WITH_MORE_INFO.includes(domain)) {
+    return domain;
+  }
+  if (HIDE_MORE_INFO.includes(domain)) {
+    return 'hidden';
+  }
+  return 'default';
+}
diff --git a/js/compatibility.js b/js/compatibility.js
index b3edbda996..744ff1e49b 100644
--- a/js/compatibility.js
+++ b/js/compatibility.js
@@ -1,3 +1,4 @@
+import 'mdn-polyfills/Array.prototype.includes';
 import 'unfetch/polyfill';
 import objAssign from 'es6-object-assign';
 
diff --git a/js/util.js b/js/util.js
index a8e5fe10af..34af033a52 100644
--- a/js/util.js
+++ b/js/util.js
@@ -7,11 +7,16 @@
  */
 
 import attributeClassNames from './common/util/attribute_class_names.js';
+import canToggleDomain from './common/util/can_toggle_domain.js';
+import canToggleState from './common/util/can_toggle_state.js';
 import computeStateDomain from './common/util/compute_state_domain.js';
 import computeStateDisplay from './common/util/compute_state_display.js';
+import featureClassNames from './common/util/feature_class_names.js';
 import formatDate from './common/util/format_date.js';
 import formatDateTime from './common/util/format_date_time.js';
 import formatTime from './common/util/format_time.js';
+import stateCardType from './common/util/state_card_type.js';
+import stateMoreInfoType from './common/util/state_more_info_type.js';
 
 window.hassUtil = window.hassUtil || {};
 
@@ -21,8 +26,13 @@ const language = navigator.languages ?
 window.fecha.masks.haDateTime = window.fecha.masks.shortTime + ' ' + window.fecha.masks.mediumDate;
 
 window.hassUtil.attributeClassNames = attributeClassNames;
+window.hassUtil.canToggleDomain = canToggleDomain;
+window.hassUtil.canToggleState = canToggleState;
 window.hassUtil.computeDomain = computeStateDomain;
 window.hassUtil.computeStateDisplay = computeStateDisplay;
+window.hassUtil.featureClassNames = featureClassNames;
 window.hassUtil.formatDate = dateObj => formatDate(dateObj, language);
 window.hassUtil.formatDateTime = dateObj => formatDateTime(dateObj, language);
 window.hassUtil.formatTime = dateObj => formatTime(dateObj, language);
+window.hassUtil.stateCardType = stateCardType;
+window.hassUtil.stateMoreInfoType = stateMoreInfoType;
diff --git a/package.json b/package.json
index 1bba80db6a..cc5dd94276 100644
--- a/package.json
+++ b/package.json
@@ -15,7 +15,7 @@
     "dev-watch": "npm run gulp watch_ru_all gen-service-worker",
     "dev-es5": "npm run gulp ru_all_es5 gen-service-worker-es5",
     "dev-watch-es5": "npm run gulp watch_ru_all_es5 gen-service-worker-es5",
-    "lint_js": "eslint src panels js --ext js,html",
+    "lint_js": "eslint src panels js test-mocha --ext js,html",
     "lint_html": "ls -1 src/home-assistant.html panels/**/ha-panel-*.html | xargs polymer lint --input",
     "mocha": "node_modules/.bin/mocha --opts test-mocha/mocha.opts",
     "test": "npm run lint_js && npm run lint_html && npm run mocha"
@@ -29,6 +29,7 @@
     "babel-plugin-transform-react-jsx": "^6.24.1",
     "babel-preset-es2015": "^6.24.1",
     "bower": "^1.8.2",
+    "chai": "^4.1.2",
     "css-slam": "^2.0.2",
     "del": "^3.0.0",
     "es6-object-assign": "^1.1.0",
@@ -58,6 +59,7 @@
     "gulp-vinyl-zip": "^2.1.0",
     "home-assistant-js-websocket": "^1.1.2",
     "html-minifier": "^3.5.6",
+    "mdn-polyfills": "^5.5.0",
     "merge-stream": "^1.0.1",
     "mocha": "^4.0.1",
     "parse5": "^3.0.3",
diff --git a/src/util/hass-util.html b/src/util/hass-util.html
index 5b5e78b35a..818b59b000 100644
--- a/src/util/hass-util.html
+++ b/src/util/hass-util.html
@@ -11,67 +11,8 @@ window.hassUtil.DEFAULT_ICON = 'mdi:bookmark';
 
 window.hassUtil.OFF_STATES = ['off', 'closed', 'unlocked'];
 
-window.hassUtil.DOMAINS_WITH_CARD = [
-  'climate',
-  'cover',
-  'configurator',
-  'input_select',
-  'input_number',
-  'input_text',
-  'media_player',
-  'scene',
-  'script',
-  'weblink',
-];
-
-window.hassUtil.DOMAINS_WITH_MORE_INFO = [
-  'alarm_control_panel', 'automation', 'camera', 'climate', 'configurator',
-  'cover', 'fan', 'group', 'history_graph', 'light', 'lock', 'media_player', 'script',
-  'sun', 'updater', 'vacuum', 'input_datetime',
-];
-
 window.hassUtil.DOMAINS_WITH_NO_HISTORY = ['camera', 'configurator', 'history_graph', 'scene'];
 
-window.hassUtil.HIDE_MORE_INFO = [
-  'input_select', 'scene', 'input_number', 'input_text'
-];
-
-// Expects featureClassNames to be an object mapping feature-bit -> className
-window.hassUtil.featureClassNames = function (stateObj, featureClassNames) {
-  if (!stateObj || !stateObj.attributes.supported_features) return '';
-
-  var features = stateObj.attributes.supported_features;
-
-  return Object.keys(featureClassNames).map(function (feature) {
-    return (features & feature) !== 0 ? featureClassNames[feature] : '';
-  }).join(' ');
-};
-
-
-window.hassUtil.canToggleState = function (hass, stateObj) {
-  var domain = window.hassUtil.computeDomain(stateObj);
-  if (domain === 'group') {
-    return stateObj.state === 'on' || stateObj.state === 'off';
-  }
-
-  return window.hassUtil.canToggleDomain(hass, domain);
-};
-
-window.hassUtil.canToggleDomain = function (hass, domain) {
-  var turnOnService;
-  var services = hass.config.services[domain];
-
-  if (domain === 'lock') {
-    turnOnService = 'lock';
-  } else if (domain === 'cover') {
-    turnOnService = 'open_cover';
-  } else {
-    turnOnService = 'turn_on';
-  }
-
-  return services && turnOnService in services;
-};
-
 // Update root's child element to be newElementTag replacing another existing child if any.
 // Copy attributes into the child element.
 window.hassUtil.dynamicContentUpdater = function (root, newElementTag, attributes) {
@@ -133,34 +74,6 @@ window.hassUtil.relativeTime.tests = [
   7, 'day',
 ];
 
-window.hassUtil.stateCardType = function (hass, stateObj) {
-  if (stateObj.state === 'unavailable') {
-    return 'display';
-  }
-
-  var domain = window.hassUtil.computeDomain(stateObj);
-
-  if (window.hassUtil.DOMAINS_WITH_CARD.indexOf(domain) !== -1) {
-    return domain;
-  } else if (window.hassUtil.canToggleState(hass, stateObj) &&
-             stateObj.attributes.control !== 'hidden') {
-    return 'toggle';
-  }
-  return 'display';
-};
-
-window.hassUtil.stateMoreInfoType = function (stateObj) {
-  var domain = window.hassUtil.computeDomain(stateObj);
-
-  if (window.hassUtil.DOMAINS_WITH_MORE_INFO.indexOf(domain) !== -1) {
-    return domain;
-  }
-  if (window.hassUtil.HIDE_MORE_INFO.indexOf(domain) !== -1) {
-    return 'hidden';
-  }
-  return 'default';
-};
-
 window.hassUtil.domainIcon = function (domain, state) {
   switch (domain) {
     case 'alarm_control_panel':
diff --git a/test-mocha/common/util/attribute_class_names_test.js b/test-mocha/common/util/attribute_class_names_test.js
index 9aaeea1940..309dd83b35 100644
--- a/test-mocha/common/util/attribute_class_names_test.js
+++ b/test-mocha/common/util/attribute_class_names_test.js
@@ -1,6 +1,6 @@
-import attributeClassNames from '../../../js/common/util/attribute_class_names';
+import { assert } from 'chai';
 
-const assert = require('assert');
+import attributeClassNames from '../../../js/common/util/attribute_class_names';
 
 describe('attributeClassNames', () => {
   const attrs = ['mock_attr1', 'mock_attr2'];
diff --git a/test-mocha/common/util/can_toggle_domain_test.js b/test-mocha/common/util/can_toggle_domain_test.js
new file mode 100644
index 0000000000..a357cd5c0e
--- /dev/null
+++ b/test-mocha/common/util/can_toggle_domain_test.js
@@ -0,0 +1,39 @@
+import { assert } from 'chai';
+
+import canToggleDomain from '../../../js/common/util/can_toggle_domain';
+
+describe('canToggleDomain', () => {
+  const hass = {
+    config: {
+      services: {
+        light: {
+          turn_on: null, // Service keys only need to be present for test
+          turn_off: null,
+        },
+        lock: {
+          lock: null,
+          unlock: null,
+        },
+        sensor: {
+          custom_service: null,
+        },
+      },
+    },
+  };
+
+  it('Detects lights toggle', () => {
+    assert.isTrue(canToggleDomain(hass, 'light'));
+  });
+
+  it('Detects locks toggle', () => {
+    assert.isTrue(canToggleDomain(hass, 'lock'));
+  });
+
+  it('Detects sensors do not toggle', () => {
+    assert.isFalse(canToggleDomain(hass, 'sensor'));
+  });
+
+  it('Detects binary sensors do not toggle', () => {
+    assert.isFalse(canToggleDomain(hass, 'binary_sensor'));
+  });
+});
diff --git a/test-mocha/common/util/can_toggle_state_test.js b/test-mocha/common/util/can_toggle_state_test.js
new file mode 100644
index 0000000000..21e5dd852c
--- /dev/null
+++ b/test-mocha/common/util/can_toggle_state_test.js
@@ -0,0 +1,40 @@
+import { assert } from 'chai';
+
+import canToggleState from '../../../js/common/util/can_toggle_state';
+
+describe('canToggleState', () => {
+  const hass = {
+    config: {
+      services: {
+        light: {
+          turn_on: null, // Service keys only need to be present for test
+          turn_off: null,
+        },
+      },
+    },
+  };
+
+  it('Detects lights toggle', () => {
+    const stateObj = {
+      entity_id: 'light.bla',
+      state: 'on',
+    };
+    assert.isTrue(canToggleState(hass, stateObj));
+  });
+
+  it('Detects group with toggle', () => {
+    const stateObj = {
+      entity_id: 'group.bla',
+      state: 'on',
+    };
+    assert.isTrue(canToggleState(hass, stateObj));
+  });
+
+  it('Detects group without toggle', () => {
+    const stateObj = {
+      entity_id: 'group.devices',
+      state: 'home',
+    };
+    assert.isFalse(canToggleState(hass, stateObj));
+  });
+});
diff --git a/test-mocha/common/util/compute_domain.js b/test-mocha/common/util/compute_domain.js
index a4668c6687..708f5ff215 100644
--- a/test-mocha/common/util/compute_domain.js
+++ b/test-mocha/common/util/compute_domain.js
@@ -1,6 +1,6 @@
-import computeDomain from '../../../js/common/util/compute_domain';
+import { assert } from 'chai';
 
-const assert = require('assert');
+import computeDomain from '../../../js/common/util/compute_domain';
 
 describe('computeDomain', () => {
   it('Returns domains', () => {
diff --git a/test-mocha/common/util/compute_state_display.js b/test-mocha/common/util/compute_state_display.js
index 00596e0742..93d9c0600d 100644
--- a/test-mocha/common/util/compute_state_display.js
+++ b/test-mocha/common/util/compute_state_display.js
@@ -1,6 +1,6 @@
-import computeStateDisplay from '../../../js/common/util/compute_state_display';
+import { assert } from 'chai';
 
-const assert = require('assert');
+import computeStateDisplay from '../../../js/common/util/compute_state_display';
 
 describe('computeStateDisplay', () => {
   const haLocalize = function (namespace, message, ...args) {
@@ -156,7 +156,7 @@ describe('computeStateDisplay', () => {
   });
 
   it('Localizes custom state', () => {
-    const altHaLocalize = function (namespace, message, ...args) {
+    const altHaLocalize = function () {
       // No matches can be found
       return null;
     };
diff --git a/test-mocha/common/util/compute_state_domain.js b/test-mocha/common/util/compute_state_domain.js
index a8d173db43..38620bd60b 100644
--- a/test-mocha/common/util/compute_state_domain.js
+++ b/test-mocha/common/util/compute_state_domain.js
@@ -1,6 +1,6 @@
-import computeStateDomain from '../../../js/common/util/compute_state_domain.js';
+import { assert } from 'chai';
 
-const assert = require('assert');
+import computeStateDomain from '../../../js/common/util/compute_state_domain.js';
 
 describe('computeStateDomain', () => {
   it('Detects sensor domain', () => {
diff --git a/test-mocha/common/util/feature_class_names_test.js b/test-mocha/common/util/feature_class_names_test.js
new file mode 100644
index 0000000000..11ea64b7c8
--- /dev/null
+++ b/test-mocha/common/util/feature_class_names_test.js
@@ -0,0 +1,56 @@
+import { assert } from 'chai';
+
+import featureClassNames from '../../../js/common/util/feature_class_names';
+
+describe('featureClassNames', () => {
+  const classNames = {
+    1: 'has-feature_a',
+    2: 'has-feature_b',
+    4: 'has-feature_c',
+    8: 'has-feature_d',
+  };
+
+  it('Skips null states', () => {
+    const stateObj = null;
+    assert.strictEqual(
+      featureClassNames(stateObj, classNames),
+      ''
+    );
+  });
+
+  it('Matches no features', () => {
+    const stateObj = {
+      attributes: {
+        supported_features: 64,
+      },
+    };
+    assert.strictEqual(
+      featureClassNames(stateObj, classNames),
+      ''
+    );
+  });
+
+  it('Matches one feature', () => {
+    const stateObj = {
+      attributes: {
+        supported_features: 72,
+      },
+    };
+    assert.strictEqual(
+      featureClassNames(stateObj, classNames),
+      'has-feature_d'
+    );
+  });
+
+  it('Matches two features', () => {
+    const stateObj = {
+      attributes: {
+        supported_features: 73,
+      },
+    };
+    assert.strictEqual(
+      featureClassNames(stateObj, classNames),
+      'has-feature_a has-feature_d'
+    );
+  });
+});
diff --git a/test-mocha/common/util/format_date.js b/test-mocha/common/util/format_date.js
index b1a1df09ce..817fd9bb5a 100644
--- a/test-mocha/common/util/format_date.js
+++ b/test-mocha/common/util/format_date.js
@@ -1,6 +1,6 @@
-import formatDate from '../../../js/common/util/format_date';
+import { assert } from 'chai';
 
-const assert = require('assert');
+import formatDate from '../../../js/common/util/format_date';
 
 describe('formatDate', () => {
   const dateObj = new Date(
diff --git a/test-mocha/common/util/format_date_time.js b/test-mocha/common/util/format_date_time.js
index fe98276f96..94540a0236 100644
--- a/test-mocha/common/util/format_date_time.js
+++ b/test-mocha/common/util/format_date_time.js
@@ -1,6 +1,6 @@
-import formatDateTime from '../../../js/common/util/format_date_time';
+import { assert } from 'chai';
 
-const assert = require('assert');
+import formatDateTime from '../../../js/common/util/format_date_time';
 
 describe('formatDateTime', () => {
   const dateObj = new Date(
diff --git a/test-mocha/common/util/format_time.js b/test-mocha/common/util/format_time.js
index 86c6784dc0..1e36c3e5d9 100644
--- a/test-mocha/common/util/format_time.js
+++ b/test-mocha/common/util/format_time.js
@@ -1,6 +1,6 @@
-import formatTime from '../../../js/common/util/format_time';
+import { assert } from 'chai';
 
-const assert = require('assert');
+import formatTime from '../../../js/common/util/format_time';
 
 describe('formatTime', () => {
   const dateObj = new Date(
diff --git a/test-mocha/common/util/location.js b/test-mocha/common/util/location.js
index b563352b3c..fefc90e6af 100644
--- a/test-mocha/common/util/location.js
+++ b/test-mocha/common/util/location.js
@@ -1,6 +1,6 @@
-import { hasLocation } from '../../../js/common/util/location';
+import { assert } from 'chai';
 
-const assert = require('assert');
+import { hasLocation } from '../../../js/common/util/location';
 
 describe('hasLocation', () => {
   it('flags states with location', () => {
diff --git a/test-mocha/common/util/state_card_type_test.js b/test-mocha/common/util/state_card_type_test.js
new file mode 100644
index 0000000000..76fe75a526
--- /dev/null
+++ b/test-mocha/common/util/state_card_type_test.js
@@ -0,0 +1,55 @@
+import { assert } from 'chai';
+
+import stateCardType from '../../../js/common/util/state_card_type';
+
+describe('stateCardType', () => {
+  const hass = {
+    config: {
+      services: {
+        light: {
+          turn_on: null, // Service keys only need to be present for test
+          turn_off: null,
+        },
+      },
+    },
+  };
+
+  it('Returns display for unavailable states', () => {
+    const stateObj = {
+      state: 'unavailable',
+    };
+    assert.strictEqual(stateCardType(hass, stateObj), 'display');
+  });
+
+  it('Returns media_player for media_player states', () => {
+    const stateObj = {
+      entity_id: 'media_player.bla',
+    };
+    assert.strictEqual(stateCardType(hass, stateObj), 'media_player');
+  });
+
+  it('Returns toggle for states that can toggle', () => {
+    const stateObj = {
+      entity_id: 'light.bla',
+      attributes: {},
+    };
+    assert.strictEqual(stateCardType(hass, stateObj), 'toggle');
+  });
+
+  it('Returns display for states with hidden control', () => {
+    const stateObj = {
+      entity_id: 'light.bla',
+      attributes: {
+        control: 'hidden',
+      },
+    };
+    assert.strictEqual(stateCardType(hass, stateObj), 'display');
+  });
+
+  it('Returns display for entities that cannot toggle', () => {
+    const stateObj = {
+      entity_id: 'sensor.bla',
+    };
+    assert.strictEqual(stateCardType(hass, stateObj), 'display');
+  });
+});
diff --git a/test-mocha/common/util/state_more_info_type_test.js b/test-mocha/common/util/state_more_info_type_test.js
new file mode 100644
index 0000000000..b9e5fa4fed
--- /dev/null
+++ b/test-mocha/common/util/state_more_info_type_test.js
@@ -0,0 +1,28 @@
+import { assert } from 'chai';
+
+import stateMoreInfoType from '../../../js/common/util/state_more_info_type';
+
+describe('stateMoreInfoType', () => {
+  it('Returns media_player for media_player states', () => {
+    const stateObj = {
+      entity_id: 'media_player.bla',
+    };
+    assert.strictEqual(stateMoreInfoType(stateObj), 'media_player');
+  });
+
+  it('Returns hidden for input_select states', () => {
+    const stateObj = {
+      entity_id: 'input_select.bla',
+      attributes: {},
+    };
+    assert.strictEqual(stateMoreInfoType(stateObj), 'hidden');
+  });
+
+  it('Returns default for switch states', () => {
+    const stateObj = {
+      entity_id: 'switch.bla',
+      attributes: {},
+    };
+    assert.strictEqual(stateMoreInfoType(stateObj), 'default');
+  });
+});
diff --git a/yarn.lock b/yarn.lock
index 213d5f46f9..3de8b1f60b 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -1707,7 +1707,7 @@ chai@^3.5.0:
     deep-eql "^0.1.3"
     type-detect "^1.0.0"
 
-chai@^4.0.2:
+chai@^4.0.2, chai@^4.1.2:
   version "4.1.2"
   resolved "https://registry.yarnpkg.com/chai/-/chai-4.1.2.tgz#0f64584ba642f0f2ace2806279f4f06ca23ad73c"
   dependencies:
@@ -5194,6 +5194,10 @@ md5@^2.2.1:
     crypt "~0.0.1"
     is-buffer "~1.1.1"
 
+mdn-polyfills@^5.5.0:
+  version "5.5.0"
+  resolved "https://registry.yarnpkg.com/mdn-polyfills/-/mdn-polyfills-5.5.0.tgz#b8ce237a0a7cbae66c56a6fdd0334b659360d364"
+
 media-typer@0.3.0:
   version "0.3.0"
   resolved "https://registry.yarnpkg.com/media-typer/-/media-typer-0.3.0.tgz#8710d7af0aa626f8fffa1ce00168545263255748"