diff --git a/background/background.js b/background/background.js
index 634559f2..050bfdc8 100644
--- a/background/background.js
+++ b/background/background.js
@@ -475,3 +475,15 @@ function updateAllTabsIcon() {
     tabs.map(t => updateIcon({tab: t}))
   );
 }
+
+function openEditor({id}) {
+  let url = '/edit.html';
+  if (id) {
+    url += `?id=${id}`;
+  }
+  if (chrome.windows && prefs.get('openEditInWindow')) {
+    chrome.windows.create(Object.assign({url}, prefs.get('windowPosition')));
+  } else {
+    openURL({url});
+  }
+}
diff --git a/background/style-manager.js b/background/style-manager.js
index 66a176d9..8b167db7 100644
--- a/background/style-manager.js
+++ b/background/style-manager.js
@@ -1,6 +1,7 @@
 /* eslint no-eq-null: 0, eqeqeq: [2, "smart"] */
-/* global createCache db calcStyleDigest normalizeStyleSections db promisify
+/* global createCache db calcStyleDigest db tryRegExp
   getStyleWithNoCode msg */
+/* exported styleManager */
 'use strict';
 
 /*
diff --git a/background/style-via-api.js b/background/style-via-api.js
index c16ddfd5..72c1138e 100644
--- a/background/style-via-api.js
+++ b/background/style-via-api.js
@@ -1,4 +1,4 @@
-/* global getStyles API_METHODS styleManager */
+/* global API_METHODS styleManager CHROME prefs */
 'use strict';
 
 API_METHODS.styleViaAPI = !CHROME && (() => {
diff --git a/background/update.js b/background/update.js
index 99bb126b..0f089cf7 100644
--- a/background/update.js
+++ b/background/update.js
@@ -1,9 +1,7 @@
-/*
-global styleSectionsEqual
-global calcStyleDigest cachedStyles getStyleWithNoCode
-global usercss semverCompare
-global API_METHODS styleManager
-*/
+/* global styleSectionsEqual prefs download tryJSONparse ignoreChromeError
+  calcStyleDigest getStyleWithNoCode debounce chromeLocal
+  usercss semverCompare
+  API_METHODS styleManager */
 'use strict';
 
 (() => {
@@ -70,7 +68,7 @@ global API_METHODS styleManager
 
   function checkStyle({
     id,
-    style = cachedStyles.byId.get(id),
+    style,
     port,
     save = true,
     ignoreDigest,
@@ -89,7 +87,7 @@ global API_METHODS styleManager
 
     'ignoreDigest' option is set on the second manual individual update check on the manage page.
     */
-    return Promise.resolve(style)
+    return fetchStyle()
       .then([calcStyleDigest][!ignoreDigest ? 0 : 'skip'])
       .then([checkIfEdited][!ignoreDigest ? 0 : 'skip'])
       .then([maybeUpdateUSO, maybeUpdateUsercss][style.usercssData ? 1 : 0])
@@ -97,6 +95,16 @@ global API_METHODS styleManager
       .then(reportSuccess)
       .catch(reportFailure);
 
+    function fetchStyle() {
+      if (style) {
+        return Promise.resolve();
+      }
+      return styleManager.get(id)
+        .then(_style => {
+          style = _style;
+        });
+    }
+
     function reportSuccess(saved) {
       log(STATES.UPDATED + ` #${style.id} ${style.name}`);
       const info = {updated: true, style: saved};
diff --git a/background/usercss-helper.js b/background/usercss-helper.js
index 3f058b0d..d0341d64 100644
--- a/background/usercss-helper.js
+++ b/background/usercss-helper.js
@@ -1,4 +1,5 @@
-/* global API_METHODS usercss chromeLocal styleManager */
+/* global API_METHODS usercss chromeLocal styleManager FIREFOX deepCopy openURL
+  download */
 'use strict';
 
 (() => {
diff --git a/content/apply.js b/content/apply.js
index 9bd701bc..faae6303 100644
--- a/content/apply.js
+++ b/content/apply.js
@@ -1,5 +1,5 @@
 /* eslint no-var: 0 */
-/* global msg */
+/* global msg API prefs */
 'use strict';
 
 (() => {
@@ -79,18 +79,18 @@
    * @param {Function} callback
    * @returns {Boolean|undefined}
    */
-  function getStylesFallback(msg) {
-    if (window !== parent &&
-        location.href !== 'about:blank') {
-      try {
-        if (parent.location.origin === location.origin &&
-            parent.location.href !== location.href) {
-          chrome.runtime.connect({name: 'getStyles:' + JSON.stringify(msg)});
-          return true;
-        }
-      } catch (e) {}
-    }
-  }
+  // function getStylesFallback(msg) {
+    // if (window !== parent &&
+        // location.href !== 'about:blank') {
+      // try {
+        // if (parent.location.origin === location.origin &&
+            // parent.location.href !== location.href) {
+          // chrome.runtime.connect({name: 'getStyles:' + JSON.stringify(msg)});
+          // return true;
+        // }
+      // } catch (e) {}
+    // }
+  // }
 
   function applyOnMessage(request) {
     if (!chrome.app && document instanceof XMLDocument && request.method !== 'ping') {
@@ -320,34 +320,6 @@
     return el;
   }
 
-  function setContentsInPageContext() {
-    try {
-      (document.head || ROOT).appendChild(document.createElement('script')).text = `(${queue => {
-        document.currentScript.remove();
-        for (const {id, code} of queue) {
-          const el = document.getElementById(id) ||
-                     document.querySelector('style.stylus[id="' + id + '"]');
-          if (!el) continue;
-          const {disabled} = el.sheet;
-          el.textContent = code;
-          el.sheet.disabled = disabled;
-        }
-      }})(${JSON.stringify(pageContextQueue)})`;
-    } catch (e) {}
-    let failedSome;
-    for (const {el, code} of pageContextQueue) {
-      if (el.textContent !== code) {
-        el.textContent = code;
-        failedSome = true;
-      }
-    }
-    if (failedSome) {
-      console.debug('Could not set code of some styles in page context, ' +
-                    'see https://github.com/openstyles/stylus/issues/461');
-    }
-    pageContextQueue.length = 0;
-  }
-
   function addStyleElement(newElement) {
     if (!ROOT) {
       return;
@@ -412,14 +384,6 @@
     return parseInt(el.id.substr(ID_PREFIX.length));
   }
 
-  function countStylesInHash(styleHash) {
-    let num = 0;
-    for (const k in styleHash) {
-      num += !isNaN(parseInt(k)) ? 1 : 0;
-    }
-    return num;
-  }
-
   function orphanCheck() {
     if (chrome.i18n && chrome.i18n.getUILanguage()) {
       return true;
diff --git a/content/install-hook-openusercss.js b/content/install-hook-openusercss.js
index 7f438513..31defada 100644
--- a/content/install-hook-openusercss.js
+++ b/content/install-hook-openusercss.js
@@ -1,3 +1,4 @@
+/* global API */
 'use strict';
 
 (() => {
diff --git a/content/install-hook-usercss.js b/content/install-hook-usercss.js
index b3e4fba8..622b3143 100644
--- a/content/install-hook-usercss.js
+++ b/content/install-hook-usercss.js
@@ -1,3 +1,4 @@
+/* global API */
 'use strict';
 
 (() => {
diff --git a/content/install-hook-userstyles.js b/content/install-hook-userstyles.js
index 94a23cf4..40ed778a 100644
--- a/content/install-hook-userstyles.js
+++ b/content/install-hook-userstyles.js
@@ -1,4 +1,4 @@
-/* global cloneInto msg */
+/* global cloneInto msg API */
 'use strict';
 
 (() => {
diff --git a/edit/applies-to-line-widget.js b/edit/applies-to-line-widget.js
index 21d18c30..1d41afbd 100644
--- a/edit/applies-to-line-widget.js
+++ b/edit/applies-to-line-widget.js
@@ -1,4 +1,6 @@
-/* global regExpTester debounce messageBox CodeMirror template colorMimicry msg */
+/* global regExpTester debounce messageBox CodeMirror template colorMimicry msg
+  $ $create t prefs tryCatch */
+/* exported createAppliesToLineWidget */
 'use strict';
 
 function createAppliesToLineWidget(cm) {
diff --git a/edit/beautify.js b/edit/beautify.js
index 617c98f4..80e0e457 100644
--- a/edit/beautify.js
+++ b/edit/beautify.js
@@ -1,7 +1,5 @@
-/*
-global CodeMirror loadScript css_beautify
-global getSectionForChild showHelp
-*/
+/* global loadScript css_beautify showHelp prefs t $ $create */
+/* exported beautify */
 'use strict';
 
 function beautify(scope) {
diff --git a/edit/codemirror-default.js b/edit/codemirror-default.js
index aa6e2f14..e92be6e4 100644
--- a/edit/codemirror-default.js
+++ b/edit/codemirror-default.js
@@ -1,4 +1,4 @@
-/* global CodeMirror prefs loadScript editor */
+/* global CodeMirror prefs loadScript editor $ template */
 
 'use strict';
 
diff --git a/edit/codemirror-factory.js b/edit/codemirror-factory.js
index 0773d0f9..cb5e4586 100644
--- a/edit/codemirror-factory.js
+++ b/edit/codemirror-factory.js
@@ -1,4 +1,5 @@
-/* global CodeMirror loadScript rerouteHotkeys */
+/* global CodeMirror loadScript rerouteHotkeys prefs $ debounce $create */
+/* exported cmFactory */
 'use strict';
 /*
 All cm instances created by this module are collected so we can broadcast prefs
diff --git a/edit/colorpicker-helper.js b/edit/colorpicker-helper.js
index 0c28939e..cae28510 100644
--- a/edit/colorpicker-helper.js
+++ b/edit/colorpicker-helper.js
@@ -1,4 +1,4 @@
-/* global CodeMirror loadScript showHelp cmFactory */
+/* global CodeMirror showHelp cmFactory onDOMready $ $create prefs t */
 'use strict';
 
 (() => {
diff --git a/edit/edit.js b/edit/edit.js
index 9420d1c3..44962cb8 100644
--- a/edit/edit.js
+++ b/edit/edit.js
@@ -1,16 +1,13 @@
-/*
-global CodeMirror loadScript
-global createSourceEditor
-global closeCurrentTab regExpTester messageBox
-global setupCodeMirror
-global beautify
-global sectionsToMozFormat
-global moveFocus editorWorker msg createSectionsEditor rerouteHotkeys
+/* global CodeMirror onDOMready prefs setupLivePrefs $ $$ $create t tHTML
+  createSourceEditor queryTabs sessionStorageHash getOwnTab FIREFOX API tryCatch
+  closeCurrentTab messageBox debounce
+  beautify
+  moveFocus msg createSectionsEditor rerouteHotkeys
 */
+/* exported showCodeMirrorPopup */
 'use strict';
 
 let saveSizeOnClose;
-let ownTabId;
 
 // direct & reverse mapping of @-moz-document keywords and internal property names
 const propertyToCss = {urls: 'url', urlPrefixes: 'url-prefix', domains: 'domain', regexps: 'regexp'};
@@ -242,29 +239,6 @@ prefs.subscribe(['editor.smartIndent'], (key, value) =>
   CodeMirror.setOption('smartIndent', value));
 
 function preinit() {
-  // make querySelectorAll enumeration code readable
-  // FIXME: don't extend native
-  ['forEach', 'some', 'indexOf', 'map'].forEach(method => {
-    NodeList.prototype[method] = Array.prototype[method];
-  });
-
-  // eslint-disable-next-line no-extend-native
-  Object.defineProperties(Array.prototype, {
-    last: {
-      get() {
-        return this[this.length - 1];
-      },
-    },
-    rotate: {
-      value: function (amount) {
-        // negative amount == rotate left
-        const r = this.slice(-amount, this.length);
-        Array.prototype.push.apply(r, this.slice(0, this.length - r.length));
-        return r;
-      },
-    },
-  });
-
   // preload the theme so that CodeMirror can calculate its metrics in DOMContentLoaded->setupLivePrefs()
   new MutationObserver((mutations, observer) => {
     const themeElement = $('#cm-theme');
@@ -302,7 +276,7 @@ function preinit() {
   }
 
   getOwnTab().then(tab => {
-    ownTabId = tab.id;
+    const ownTabId = tab.id;
 
     // use browser history back when 'back to manage' is clicked
     if (sessionStorageHash('manageStylesHistory').value[ownTabId] === location.href) {
@@ -446,21 +420,6 @@ function initStyleData() {
   }
 }
 
-function showSectionHelp(event) {
-  event.preventDefault();
-  showHelp(t('styleSectionsTitle'), t('sectionHelp'));
-}
-
-function showAppliesToHelp(event) {
-  event.preventDefault();
-  showHelp(t('appliesLabel'), t('appliesHelp'));
-}
-
-function showToMozillaHelp(event) {
-  event.preventDefault();
-  showHelp(t('styleMozillaFormatHeading'), t('styleToMozillaFormatHelp'));
-}
-
 function showHelp(title = '', body) {
   const div = $('#help-popup');
   div.className = '';
@@ -559,20 +518,6 @@ function showCodeMirrorPopup(title, html, options) {
   return popup;
 }
 
-function setGlobalProgress(done, total) {
-  const progressElement = $('#global-progress') ||
-    total && document.body.appendChild($create('#global-progress'));
-  if (total) {
-    const progress = (done / Math.max(done, total) * 100).toFixed(1);
-    progressElement.style.borderLeftWidth = progress + 'vw';
-    setTimeout(() => {
-      progressElement.title = progress + '%';
-    });
-  } else {
-    $.remove(progressElement);
-  }
-}
-
 function hideLintHeaderOnScroll() {
   // workaround part2 for the <details> not showing its toggle icon: hide <summary> on scroll
   const newOpacity = this.scrollTop === 0 ? '' : '0';
@@ -610,14 +555,3 @@ function isWindowMaximized() {
     window.outerHeight < screen.availHeight + 10
   );
 }
-
-function toggleContextMenuDelete(event) {
-  if (chrome.contextMenus && event.button === 2 && prefs.get('editor.contextDelete')) {
-    chrome.contextMenus.update('editor.contextDelete', {
-      enabled: Boolean(
-        this.selectionStart !== this.selectionEnd ||
-        this.somethingSelected && this.somethingSelected()
-      ),
-    }, ignoreChromeError);
-  }
-}
diff --git a/edit/editor-worker.js b/edit/editor-worker.js
index 1323ea72..aaf4bd46 100644
--- a/edit/editor-worker.js
+++ b/edit/editor-worker.js
@@ -1,3 +1,4 @@
+/* exported editorWorker */
 'use strict';
 
 // eslint-disable-next-line no-var
diff --git a/js/exclusions.js b/edit/exclusions.js
similarity index 94%
rename from js/exclusions.js
rename to edit/exclusions.js
index aec673e3..4e143949 100644
--- a/js/exclusions.js
+++ b/edit/exclusions.js
@@ -1,8 +1,4 @@
-/*
-global messageBox resolveWith
-gloabl editor showHelp getSectionsHashes
-global popupExclusions
-*/
+/* global showHelp $ $$ debounce API template t */
 'use strict';
 
 const exclusions = (() => {
@@ -142,9 +138,9 @@ const exclusions = (() => {
     if (msg.method === 'exclusionsUpdated' && msg.style && msg.style.exclusions) {
       update({list: Object.keys(msg.style.exclusions), isUpdating: true});
       // update popup, if loaded
-      if (typeof popupExclusions !== 'undefined') {
-        popupExclusions.selectExclusions(msg.style.exclusions);
-      }
+      // if (typeof popupExclusions !== 'undefined') {
+        // popupExclusions.selectExclusions(msg.style.exclusions);
+      // }
     }
   }
 
@@ -162,7 +158,6 @@ const exclusions = (() => {
       style.exclusions = exclusionList;
       style.reason = 'exclusionsUpdated';
       API.saveStyle(style);
-      notifyAllTabs({method: 'exclusionsUpdated', style, id, excluded: exclusionList});
     });
   }
 
diff --git a/edit/global-search.js b/edit/global-search.js
index d364ec60..c160de16 100644
--- a/edit/global-search.js
+++ b/edit/global-search.js
@@ -1,6 +1,5 @@
-/* global CodeMirror */
-/* global focusAccessibility */
-/* global colorMimicry editor */
+/* global CodeMirror focusAccessibility colorMimicry editor
+  onDOMready $ $$ $create t debounce tryRegExp stringAsRegExp template */
 'use strict';
 
 onDOMready().then(() => {
diff --git a/edit/linter-config-dialog.js b/edit/linter-config-dialog.js
index c06ce9ba..310bf2b5 100644
--- a/edit/linter-config-dialog.js
+++ b/edit/linter-config-dialog.js
@@ -1,5 +1,6 @@
 /* global memoize editorWorker showCodeMirrorPopup loadScript messageBox
-  LINTER_DEFAULTS rerouteHotkeys */
+  LINTER_DEFAULTS rerouteHotkeys $ $create $createLink tryJSONparse t
+  chromeSync */
 'use strict';
 
 (() => {
diff --git a/edit/linter-defaults.js b/edit/linter-defaults.js
index e02e5420..a004b2b8 100644
--- a/edit/linter-defaults.js
+++ b/edit/linter-defaults.js
@@ -1,7 +1,7 @@
+/* exported LINTER_DEFAULTS */
 'use strict';
 
-// eslint-disable-next-line no-var
-var LINTER_DEFAULTS = (() => {
+const LINTER_DEFAULTS = (() => {
   const SEVERITY = {severity: 'warning'};
   const STYLELINT = {
     // 'sugarss' is a indent-based syntax like Sass or Stylus
diff --git a/edit/linter-engines.js b/edit/linter-engines.js
index f884ceda..7f7717b8 100644
--- a/edit/linter-engines.js
+++ b/edit/linter-engines.js
@@ -1,4 +1,4 @@
-/* global LINTER_DEFAULTS linter editorWorker */
+/* global LINTER_DEFAULTS linter editorWorker prefs chromeSync */
 'use strict';
 
 (() => {
diff --git a/edit/linter-help-dialog.js b/edit/linter-help-dialog.js
index 7946a6e5..f1c6d18c 100644
--- a/edit/linter-help-dialog.js
+++ b/edit/linter-help-dialog.js
@@ -1,4 +1,5 @@
-/* global showHelp editorWorker memoize */
+/* global showHelp editorWorker memoize $ $create $createLink t */
+/* exported createLinterHelpDialog */
 'use strict';
 
 function createLinterHelpDialog(getIssues) {
diff --git a/edit/linter-meta.js b/edit/linter-meta.js
index 4233c402..b453df9c 100644
--- a/edit/linter-meta.js
+++ b/edit/linter-meta.js
@@ -1,4 +1,5 @@
-/* global linter */
+/* global linter API */
+/* exported createMetaCompiler */
 'use strict';
 
 function createMetaCompiler(cm) {
diff --git a/edit/linter-report.js b/edit/linter-report.js
index 7dc74f0d..df7fda83 100644
--- a/edit/linter-report.js
+++ b/edit/linter-report.js
@@ -1,7 +1,6 @@
-/* global linter editor clipString createLinterHelpDialog makeSectionVisible */
+/* global linter editor clipString createLinterHelpDialog $ $create */
 'use strict';
 
-// eslint-disable-next-line no-var
 Object.assign(linter, (() => {
   const tables = new Map();
   const helpDialog = createLinterHelpDialog(getIssues);
diff --git a/edit/linter.js b/edit/linter.js
index 5cb7f779..a8d927fa 100644
--- a/edit/linter.js
+++ b/edit/linter.js
@@ -1,7 +1,8 @@
+/* global prefs */
 'use strict';
 
-// eslint-disable-next-line no-var
-var linter = (() => {
+/* exported linter */
+const linter = (() => {
   const lintingUpdatedListeners = [];
   const unhookListeners = [];
   const linters = [];
diff --git a/edit/live-preview.js b/edit/live-preview.js
index f02a5cbd..c2ff3ca4 100644
--- a/edit/live-preview.js
+++ b/edit/live-preview.js
@@ -1,4 +1,5 @@
-/* global messageBox editor */
+/* global messageBox editor $ prefs */
+/* exported createLivePreview */
 'use strict';
 
 function createLivePreview(preprocess) {
diff --git a/edit/match-highlighter-helper.js b/edit/match-highlighter-helper.js
index 34e598a4..8396a7ed 100644
--- a/edit/match-highlighter-helper.js
+++ b/edit/match-highlighter-helper.js
@@ -1,4 +1,4 @@
-/* global CodeMirror */
+/* global CodeMirror prefs */
 'use strict';
 
 (() => {
diff --git a/edit/regexp-tester.js b/edit/regexp-tester.js
index 09c4125d..4ba609ba 100644
--- a/edit/regexp-tester.js
+++ b/edit/regexp-tester.js
@@ -1,8 +1,8 @@
-/* global showHelp */
+/* global showHelp $ $create tryRegExp queryTabs URLS t template openURL */
+/* exported regExpTester */
 'use strict';
 
-// eslint-disable-next-line no-var
-var regExpTester = (() => {
+const regExpTester = (() => {
   const GET_FAVICON_URL = 'https://www.google.com/s2/favicons?domain=';
   const OWN_ICON = chrome.runtime.getManifest().icons['16'];
   const cachedRegexps = new Map();
diff --git a/edit/reroute-hotkeys.js b/edit/reroute-hotkeys.js
index 75945b99..5ca2f149 100644
--- a/edit/reroute-hotkeys.js
+++ b/edit/reroute-hotkeys.js
@@ -1,4 +1,5 @@
-/* global CodeMirror editor */
+/* global CodeMirror editor debounce */
+/* exported rerouteHotkeys */
 'use strict';
 
 const rerouteHotkeys = (() => {
diff --git a/edit/sections-editor.js b/edit/sections-editor.js
index db2f2be1..b107361f 100644
--- a/edit/sections-editor.js
+++ b/edit/sections-editor.js
@@ -1,10 +1,11 @@
-/* global dirtyReporter showToMozillaHelp
-  showSectionHelp toggleContextMenuDelete setGlobalProgress maximizeCodeHeight
-  CodeMirror nextPrevEditorOnKeydown showAppliesToHelp propertyToCss
+/* global dirtyReporter showHelp prefs ignoreChromeError
+  CodeMirror propertyToCss
   regExpTester linter createLivePreview showCodeMirrorPopup
   sectionsToMozFormat editorWorker messageBox clipString beautify
-  rerouteHotkeys cmFactory CssToProperty
+  rerouteHotkeys cmFactory CssToProperty template $ $$ $create t FIREFOX API
+  debounce tryRegExp
 */
+/* exported createSectionsEditor */
 'use strict';
 
 function createResizeGrip(cm) {
@@ -98,6 +99,7 @@ function createSectionsEditor(style) {
   $('#to-mozilla-help').addEventListener('click', showToMozillaHelp);
   $('#from-mozilla').addEventListener('click', () => fromMozillaFormat());
   $('#save-button').addEventListener('click', saveStyle);
+  // FIXME: this element doesn't exist?
   $('#sections-help').addEventListener('click', showSectionHelp);
 
   document.addEventListener('wheel', scrollEntirePageOnCtrlShift);
@@ -148,6 +150,46 @@ function createSectionsEditor(style) {
     getSearchableInputs,
   };
 
+  function toggleContextMenuDelete(event) {
+    if (chrome.contextMenus && event.button === 2 && prefs.get('editor.contextDelete')) {
+      chrome.contextMenus.update('editor.contextDelete', {
+        enabled: Boolean(
+          this.selectionStart !== this.selectionEnd ||
+          this.somethingSelected && this.somethingSelected()
+        ),
+      }, ignoreChromeError);
+    }
+  }
+
+  function setGlobalProgress(done, total) {
+    const progressElement = $('#global-progress') ||
+      total && document.body.appendChild($create('#global-progress'));
+    if (total) {
+      const progress = (done / Math.max(done, total) * 100).toFixed(1);
+      progressElement.style.borderLeftWidth = progress + 'vw';
+      setTimeout(() => {
+        progressElement.title = progress + '%';
+      });
+    } else {
+      $.remove(progressElement);
+    }
+  }
+
+  function showToMozillaHelp(event) {
+    event.preventDefault();
+    showHelp(t('styleMozillaFormatHeading'), t('styleToMozillaFormatHelp'));
+  }
+
+  function showAppliesToHelp(event) {
+    event.preventDefault();
+    showHelp(t('appliesLabel'), t('appliesHelp'));
+  }
+
+  function showSectionHelp(event) {
+    event.preventDefault();
+    showHelp(t('styleSectionsTitle'), t('sectionHelp'));
+  }
+
   function getSearchableInputs(cm) {
     return sections.find(s => s.cm === cm).appliesTo.map(a => a.valueEl).filter(Boolean);
   }
diff --git a/edit/show-keymap-help.js b/edit/show-keymap-help.js
index 66dc710a..62481787 100644
--- a/edit/show-keymap-help.js
+++ b/edit/show-keymap-help.js
@@ -1,4 +1,5 @@
-/* global CodeMirror showHelp */
+/* global CodeMirror showHelp onDOMready $ $$ $create template t
+  prefs stringAsRegExp */
 'use strict';
 
 onDOMready().then(() => {
diff --git a/edit/source-editor.js b/edit/source-editor.js
index 107a8c5c..c0476f80 100644
--- a/edit/source-editor.js
+++ b/edit/source-editor.js
@@ -1,9 +1,9 @@
-/*
-global CodeMirror dirtyReporter
-global createAppliesToLineWidget messageBox
-global sectionsToMozFormat
-global createMetaCompiler linter createLivePreview cmFactory
-*/
+/* global dirtyReporter
+  createAppliesToLineWidget messageBox
+  sectionsToMozFormat
+  createMetaCompiler linter createLivePreview cmFactory $ $create API prefs t
+  chromeSync */
+/* exported createSourceEditor */
 'use strict';
 
 function createSourceEditor(style) {
diff --git a/edit/util.js b/edit/util.js
index a16c742f..cc18b515 100644
--- a/edit/util.js
+++ b/edit/util.js
@@ -1,3 +1,4 @@
+/* exported dirtyReporter memoize clipString sectionsToMozFormat */
 'use strict';
 
 function dirtyReporter() {
diff --git a/install-usercss/install-usercss.js b/install-usercss/install-usercss.js
index 7164c8de..8b375e60 100644
--- a/install-usercss/install-usercss.js
+++ b/install-usercss/install-usercss.js
@@ -1,5 +1,5 @@
-/* global CodeMirror semverCompare closeCurrentTab */
-/* global messageBox download chromeLocal */
+/* global CodeMirror semverCompare closeCurrentTab messageBox download
+  $ $$ $create $createLink t prefs API getTab */
 'use strict';
 
 (() => {
diff --git a/js/cache.js b/js/cache.js
index 31e3df6e..f86f4331 100644
--- a/js/cache.js
+++ b/js/cache.js
@@ -1,5 +1,7 @@
+/* exported createCache */
 'use strict';
 
+// create a FIFO limit-size map.
 function createCache(size = 1000) {
   const map = new Map();
   const buffer = Array(size);
diff --git a/js/dom.js b/js/dom.js
index 7ffb9ce6..a1ae0180 100644
--- a/js/dom.js
+++ b/js/dom.js
@@ -1,9 +1,35 @@
+/* global prefs */
+/* exported scrollElementIntoView animateElement enforceInputRange $createLink
+  setupLivePrefs moveFocus */
 'use strict';
 
 if (!/^Win\d+/.test(navigator.platform)) {
   document.documentElement.classList.add('non-windows');
 }
 
+// make querySelectorAll enumeration code readable
+// FIXME: avoid extending native?
+['forEach', 'some', 'indexOf', 'map'].forEach(method => {
+  NodeList.prototype[method] = Array.prototype[method];
+});
+
+// eslint-disable-next-line no-extend-native
+Object.defineProperties(Array.prototype, {
+  last: {
+    get() {
+      return this[this.length - 1];
+    },
+  },
+  rotate: {
+    value: function (amount) {
+      // negative amount == rotate left
+      const r = this.slice(-amount, this.length);
+      Array.prototype.push.apply(r, this.slice(0, this.length - r.length));
+      return r;
+    },
+  },
+});
+
 // polyfill for old browsers to enable [...results] and for-of
 for (const type of [NodeList, NamedNodeMap, HTMLCollection, HTMLAllCollection]) {
   if (!type.prototype[Symbol.iterator]) {
diff --git a/js/localization.js b/js/localization.js
index b33c3c29..e4a8de10 100644
--- a/js/localization.js
+++ b/js/localization.js
@@ -1,3 +1,5 @@
+/* global tryCatch */
+/* exported tHTML formatDate */
 'use strict';
 
 const template = {};
diff --git a/js/messaging.js b/js/messaging.js
index fc1cb78a..e8335bd9 100644
--- a/js/messaging.js
+++ b/js/messaging.js
@@ -1,14 +1,13 @@
-/*
-global BG: true
-global FIREFOX: true
-global onRuntimeMessage applyOnMessage
-*/
+/* exported getActiveTab onTabReady stringAsRegExp getTabRealURL openURL
+  getStyleWithNoCode tryRegExp sessionStorageHash download
+  closeCurrentTab */
 'use strict';
 
 const CHROME = Boolean(chrome.app) && parseInt(navigator.userAgent.match(/Chrom\w+\/(?:\d+\.){2}(\d+)|$/)[1]);
 const OPERA = Boolean(chrome.app) && parseFloat(navigator.userAgent.match(/\bOPR\/(\d+\.\d+)|$/)[1]);
 const VIVALDI = Boolean(chrome.app) && navigator.userAgent.includes('Vivaldi');
-const ANDROID = !chrome.windows;
+// FIXME: who use this?
+// const ANDROID = !chrome.windows;
 let FIREFOX = !chrome.app && parseFloat(navigator.userAgent.match(/\bFirefox\/(\d+\.\d+)|$/)[1]);
 
 if (!CHROME && !chrome.browserAction.openPopup) {
@@ -120,13 +119,6 @@ function getActiveTab() {
     .then(tabs => tabs[0]);
 }
 
-
-function getActiveTabRealURL() {
-  return getActiveTab()
-    .then(getTabRealURL);
-}
-
-
 function getTabRealURL(tab) {
   return new Promise(resolve => {
     if (tab.url !== 'chrome://newtab/' || URLS.chromeProtectsNTP) {
@@ -487,27 +479,6 @@ function download(url, {
   }
 }
 
-
-function invokeOrPostpone(isInvoke, fn, ...args) {
-  return isInvoke
-    ? fn(...args)
-    : setTimeout(invokeOrPostpone, 0, true, fn, ...args);
-}
-
-
-function openEditor({id}) {
-  let url = '/edit.html';
-  if (id) {
-    url += `?id=${id}`;
-  }
-  if (chrome.windows && prefs.get('openEditInWindow')) {
-    chrome.windows.create(Object.assign({url}, prefs.get('windowPosition')));
-  } else {
-    openURL({url});
-  }
-}
-
-
 function closeCurrentTab() {
   // https://bugzilla.mozilla.org/show_bug.cgi?id=1409375
   getOwnTab().then(tab => {
@@ -516,6 +487,3 @@ function closeCurrentTab() {
     }
   });
 }
-
-// FIXME: remove this when #510 is merged
-function notifyAllTabs() {}
diff --git a/js/moz-parser.js b/js/moz-parser.js
index f5e7eb8e..32a73afb 100644
--- a/js/moz-parser.js
+++ b/js/moz-parser.js
@@ -1,4 +1,5 @@
 /* global parserlib */
+/* exported parseMozFormat */
 'use strict';
 
 /**
diff --git a/js/msg.js b/js/msg.js
index 20b17585..afc6d66a 100644
--- a/js/msg.js
+++ b/js/msg.js
@@ -1,4 +1,5 @@
 /* global promisify deepCopy */
+/* exported msg API */
 // deepCopy is only used if the script is executed in extension pages.
 'use strict';
 
diff --git a/js/prefs.js b/js/prefs.js
index f798a96a..cf0776ef 100644
--- a/js/prefs.js
+++ b/js/prefs.js
@@ -1,4 +1,3 @@
-/* global deepCopy debounce API tryJSONparse chromeSync FIREFOX CHROME */
 /* exported prefs */
 'use strict';
 
diff --git a/js/storage-util.js b/js/storage-util.js
index 34924f55..044ba56a 100644
--- a/js/storage-util.js
+++ b/js/storage-util.js
@@ -1,4 +1,4 @@
-/* global loadScript tryJSONparse API */
+/* global loadScript tryJSONparse */
 /* exported chromeLocal chromeSync */
 'use strict';