--- a/.eslintignore
+++ b/.eslintignore
@@ -1,8 +1,11 @@
+# Allow linting of .eslintrc.js files.
+!**/.eslintrc.js
+
 # Always ignore node_modules.
 **/node_modules/**/*.*
 
 # Exclude expected objdirs.
 obj*/**
 
 # We ignore all these directories by default, until we get them enabled.
 # If you are enabling a directory, please add directory specific exclusions

rename from .eslintrc
rename to .eslintrc.js
--- a/.eslintrc
+++ b/.eslintrc.js
@@ -1,12 +1,14 @@
-{
+"use strict";
+
+module.exports = {
   // When adding items to this file please check for effects on sub-directories.
   "plugins": [
     "mozilla"
   ],
   "rules": {
     "mozilla/import-globals": 1,
   },
   "env": {
     "es6": true
   },
-}
+};

rename from accessible/.eslintrc
rename to accessible/.eslintrc.js
--- a/accessible/.eslintrc
+++ b/accessible/.eslintrc.js
@@ -1,15 +1,17 @@
-{
+"use strict";
+
+module.exports = {
   "extends": [
-    "../.eslintrc"
+    "../.eslintrc.js"
   ],
   "globals": {
     "Cc": true,
     "Ci": true,
     "Components": true,
     "console": true,
     "Cu": true,
     "dump": true,
     "Services": true,
     "XPCOMUtils": true
   }
-}
+};

rename from accessible/tests/browser/.eslintrc
rename to accessible/tests/browser/.eslintrc.js
--- a/accessible/tests/browser/.eslintrc
+++ b/accessible/tests/browser/.eslintrc.js
@@ -1,11 +1,13 @@
-{
+"use strict";
+
+module.exports = { // eslint-disable-line no-undef
   "extends": [
-    "../../../testing/mochitest/browser.eslintrc"
+    "../../../testing/mochitest/browser.eslintrc.js"
   ],
   // All globals made available in the test environment.
   "globals": {
     // Content scripts have global 'content' object
     "content": true,
 
     "add_task": true,
 
@@ -41,17 +43,17 @@
     "loadFrameScripts": true,
     "Logger": true,
     "MOCHITESTS_DIR": true,
     "waitForEvent": true,
     "waitForMultipleEvents": true,
     "invokeSetAttribute": true,
     "invokeSetStyle": true,
     "invokeFocus": true,
-    "findAccessibleChildByID": true,
+    "findAccessibleChildByID": true
   },
   "rules": {
     "mozilla/mark-test-function-used": 1,
     "mozilla/no-aArgs": 1,
     "mozilla/no-cpows-in-tests": 1,
     "mozilla/reject-importGlobalProperties": 1,
     "mozilla/var-only-at-top-level": 1,
 
@@ -207,11 +209,11 @@
     "no-octal-escape": 0,
     "no-undef-init": 2,
     "no-unexpected-multiline": 2,
     "object-curly-spacing": 0,
     "no-unused-expressions": 0,
     "no-void": 0,
     "no-wrap-func": 0,
     "operator-assignment": 0,
-    "operator-linebreak": [2, "after"],
+    "operator-linebreak": [2, "after"]
   }
-}
+};

rename from browser/.eslintrc
rename to browser/.eslintrc.js
--- a/browser/.eslintrc
+++ b/browser/.eslintrc.js
@@ -1,5 +1,7 @@
-{
+"use strict";
+
+module.exports = {
   "extends": [
-    "../toolkit/.eslintrc"
+    "../toolkit/.eslintrc.js"
   ],
-}
+};

rename from browser/base/content/test/alerts/.eslintrc
rename to browser/base/content/test/alerts/.eslintrc.js
--- a/browser/base/content/test/alerts/.eslintrc
+++ b/browser/base/content/test/alerts/.eslintrc.js
@@ -1,5 +1,7 @@
-{
+"use strict";
+
+module.exports = {
   "extends": [
-    "../../../../../testing/mochitest/browser.eslintrc"
+    "../../../../../testing/mochitest/browser.eslintrc.js"
   ]
-}
+};

rename from browser/base/content/test/chrome/.eslintrc
rename to browser/base/content/test/chrome/.eslintrc.js
--- a/browser/base/content/test/chrome/.eslintrc
+++ b/browser/base/content/test/chrome/.eslintrc.js
@@ -1,5 +1,7 @@
-{
+"use strict";
+
+module.exports = {
   "extends": [
-    "../../../../../testing/mochitest/chrome.eslintrc"
+    "../../../../../testing/mochitest/chrome.eslintrc.js"
   ]
-}
+};

rename from browser/base/content/test/general/.eslintrc
rename to browser/base/content/test/general/.eslintrc.js
--- a/browser/base/content/test/general/.eslintrc
+++ b/browser/base/content/test/general/.eslintrc.js
@@ -1,6 +1,8 @@
-{
+"use strict";
+
+module.exports = {
   "extends": [
-    "../../../../../testing/mochitest/browser.eslintrc",
-    "../../../../../testing/mochitest/mochitest.eslintrc",
+    "../../../../../testing/mochitest/browser.eslintrc.js",
+    "../../../../../testing/mochitest/mochitest.eslintrc.js",
   ]
-}
+};

rename from browser/base/content/test/newtab/.eslintrc
rename to browser/base/content/test/newtab/.eslintrc.js
--- a/browser/base/content/test/newtab/.eslintrc
+++ b/browser/base/content/test/newtab/.eslintrc.js
@@ -1,5 +1,7 @@
-{
+"use strict";
+
+module.exports = {
   "extends": [
-    "../../../../../testing/mochitest/browser.eslintrc"
+    "../../../../../testing/mochitest/browser.eslintrc.js"
   ]
-}
+};

rename from browser/base/content/test/plugins/.eslintrc
rename to browser/base/content/test/plugins/.eslintrc.js
--- a/browser/base/content/test/plugins/.eslintrc
+++ b/browser/base/content/test/plugins/.eslintrc.js
@@ -1,5 +1,7 @@
-{
+"use strict";
+
+module.exports = {
   "extends": [
-    "../../../../../testing/mochitest/browser.eslintrc"
+    "../../../../../testing/mochitest/browser.eslintrc.js"
   ]
-}
+};

rename from browser/base/content/test/popupNotifications/.eslintrc
rename to browser/base/content/test/popupNotifications/.eslintrc.js
--- a/browser/base/content/test/popupNotifications/.eslintrc
+++ b/browser/base/content/test/popupNotifications/.eslintrc.js
@@ -1,5 +1,7 @@
-{
+"use strict";
+
+module.exports = {
   "extends": [
-    "../../../../../testing/mochitest/browser.eslintrc"
+    "../../../../../testing/mochitest/browser.eslintrc.js"
   ]
-}
+};

rename from browser/base/content/test/referrer/.eslintrc
rename to browser/base/content/test/referrer/.eslintrc.js
--- a/browser/base/content/test/referrer/.eslintrc
+++ b/browser/base/content/test/referrer/.eslintrc.js
@@ -1,5 +1,7 @@
-{
+"use strict";
+
+module.exports = {
   "extends": [
-    "../../../../../testing/mochitest/browser.eslintrc"
+    "../../../../../testing/mochitest/browser.eslintrc.js"
   ]
-}
+};

rename from browser/base/content/test/social/.eslintrc
rename to browser/base/content/test/social/.eslintrc.js
--- a/browser/base/content/test/social/.eslintrc
+++ b/browser/base/content/test/social/.eslintrc.js
@@ -1,5 +1,7 @@
-{
+"use strict";
+
+module.exports = {
   "extends": [
-    "../../../../../testing/mochitest/browser.eslintrc"
+    "../../../../../testing/mochitest/browser.eslintrc.js"
   ]
-}
+};

rename from browser/components/contextualidentity/test/browser/.eslintrc
rename to browser/components/contextualidentity/test/browser/.eslintrc.js
--- a/browser/components/contextualidentity/test/browser/.eslintrc
+++ b/browser/components/contextualidentity/test/browser/.eslintrc.js
@@ -1,5 +1,7 @@
-{
+"use strict";
+
+module.exports = {
   "extends": [
-    "../../../../../testing/mochitest/browser.eslintrc"
+    "../../../../../testing/mochitest/browser.eslintrc.js"
   ]
-}
+};

rename from browser/components/customizableui/test/.eslintrc
rename to browser/components/customizableui/test/.eslintrc.js
--- a/browser/components/customizableui/test/.eslintrc
+++ b/browser/components/customizableui/test/.eslintrc.js
@@ -1,5 +1,7 @@
-{
+"use strict";
+
+module.exports = {
   "extends": [
-    "../../../../testing/mochitest/browser.eslintrc"
+    "../../../../testing/mochitest/browser.eslintrc.js"
   ]
-}
+};

rename from browser/components/dirprovider/tests/unit/.eslintrc
rename to browser/components/dirprovider/tests/unit/.eslintrc.js
--- a/browser/components/dirprovider/tests/unit/.eslintrc
+++ b/browser/components/dirprovider/tests/unit/.eslintrc.js
@@ -1,5 +1,7 @@
-{
+"use strict";
+
+module.exports = {
   "extends": [
-    "../../../../../testing/xpcshell/xpcshell.eslintrc"
+    "../../../../../testing/xpcshell/xpcshell.eslintrc.js"
   ]
-}
+};

rename from browser/components/downloads/test/browser/.eslintrc
rename to browser/components/downloads/test/browser/.eslintrc.js
--- a/browser/components/downloads/test/browser/.eslintrc
+++ b/browser/components/downloads/test/browser/.eslintrc.js
@@ -1,5 +1,7 @@
-{
+"use strict";
+
+module.exports = {
   "extends": [
-    "../../../../../testing/mochitest/browser.eslintrc"
+    "../../../../../testing/mochitest/browser.eslintrc.js"
   ]
-}
+};

rename from browser/components/downloads/test/unit/.eslintrc
rename to browser/components/downloads/test/unit/.eslintrc.js
--- a/browser/components/downloads/test/unit/.eslintrc
+++ b/browser/components/downloads/test/unit/.eslintrc.js
@@ -1,5 +1,7 @@
-{
+"use strict";
+
+module.exports = {
   "extends": [
-    "../../../../../testing/xpcshell/xpcshell.eslintrc"
+    "../../../../../testing/xpcshell/xpcshell.eslintrc.js"
   ]
-}
+};

rename from browser/components/extensions/.eslintrc
rename to browser/components/extensions/.eslintrc.js
--- a/browser/components/extensions/.eslintrc
+++ b/browser/components/extensions/.eslintrc.js
@@ -1,10 +1,12 @@
-{
-  "extends": "../../../toolkit/components/extensions/.eslintrc",
+"use strict";
+
+module.exports = {  // eslint-disable-line no-undef
+  "extends": "../../../toolkit/components/extensions/.eslintrc.js",
 
   "globals": {
     "AllWindowEvents": true,
     "browserActionFor": true,
     "currentWindow": true,
     "EventEmitter": true,
     "getCookieStoreIdForTab": true,
     "IconDetails": true,
@@ -12,11 +14,9 @@
     "pageActionFor": true,
     "PanelPopup": true,
     "TabContext": true,
     "ViewPopup": true,
     "WindowEventManager": true,
     "WindowListManager": true,
     "WindowManager": true,
   },
-}
-
-
+};

rename from browser/components/extensions/test/browser/.eslintrc
rename to browser/components/extensions/test/browser/.eslintrc.js
--- a/browser/components/extensions/test/browser/.eslintrc
+++ b/browser/components/extensions/test/browser/.eslintrc.js
@@ -1,10 +1,12 @@
-{
-  "extends": "../../../../../testing/mochitest/browser.eslintrc",
+"use strict";
+
+module.exports = {  // eslint-disable-line no-undef
+  "extends": "../../../../../testing/mochitest/browser.eslintrc.js",
 
   "env": {
     "webextensions": true,
   },
 
   "globals": {
     "NetUtil": true,
     "XPCOMUtils": true,
@@ -21,10 +23,10 @@
     "clickPageAction": true,
     "closeContextMenu": true,
     "closeExtensionContextMenu": true,
     "focusWindow": true,
     "makeWidgetId": true,
     "openContextMenu": true,
     "openExtensionContextMenu": true,
     "CustomizableUI": true,
-  }
-}
+  },
+};

rename from browser/components/extensions/test/xpcshell/.eslintrc
rename to browser/components/extensions/test/xpcshell/.eslintrc.js
--- a/browser/components/extensions/test/xpcshell/.eslintrc
+++ b/browser/components/extensions/test/xpcshell/.eslintrc.js
@@ -1,7 +1,9 @@
-{
-  "extends": "../../../../../testing/xpcshell/xpcshell.eslintrc",
+"use strict";
+
+module.exports = {  // eslint-disable-line no-undef
+  "extends": "../../../../../testing/xpcshell/xpcshell.eslintrc.js",
 
   "globals": {
     "browser": false,
   },
-}
+};

rename from browser/components/feeds/test/.eslintrc
rename to browser/components/feeds/test/.eslintrc.js
--- a/browser/components/feeds/test/.eslintrc
+++ b/browser/components/feeds/test/.eslintrc.js
@@ -1,5 +1,7 @@
-{
+"use strict";
+
+module.exports = {
   "extends": [
-    "../../../../testing/mochitest/mochitest.eslintrc"
+    "../../../../testing/mochitest/mochitest.eslintrc.js"
   ]
-}
+};

rename from browser/components/feeds/test/chrome/.eslintrc
rename to browser/components/feeds/test/chrome/.eslintrc.js
--- a/browser/components/feeds/test/chrome/.eslintrc
+++ b/browser/components/feeds/test/chrome/.eslintrc.js
@@ -1,5 +1,7 @@
-{
+"use strict";
+
+module.exports = {
   "extends": [
-    "../../../../../testing/mochitest/chrome.eslintrc"
+    "../../../../../testing/mochitest/chrome.eslintrc.js"
   ]
-}
+};

rename from browser/components/feeds/test/unit/.eslintrc
rename to browser/components/feeds/test/unit/.eslintrc.js
--- a/browser/components/feeds/test/unit/.eslintrc
+++ b/browser/components/feeds/test/unit/.eslintrc.js
@@ -1,5 +1,7 @@
-{
+"use strict";
+
+module.exports = {
   "extends": [
-    "../../../../../testing/xpcshell/xpcshell.eslintrc"
+    "../../../../../testing/xpcshell/xpcshell.eslintrc.js"
   ]
-}
+};

rename from browser/components/migration/tests/unit/.eslintrc
rename to browser/components/migration/tests/unit/.eslintrc.js
--- a/browser/components/migration/tests/unit/.eslintrc
+++ b/browser/components/migration/tests/unit/.eslintrc.js
@@ -1,5 +1,7 @@
-{
+"use strict";
+
+module.exports = {
   "extends": [
-    "../../../../../testing/xpcshell/xpcshell.eslintrc"
+    "../../../../../testing/xpcshell/xpcshell.eslintrc.js"
   ]
-}
+};

rename from browser/components/newtab/tests/browser/.eslintrc
rename to browser/components/newtab/tests/browser/.eslintrc.js
--- a/browser/components/newtab/tests/browser/.eslintrc
+++ b/browser/components/newtab/tests/browser/.eslintrc.js
@@ -1,5 +1,7 @@
-{
+"use strict";
+
+module.exports = {
   "extends": [
-    "../../../../../testing/mochitest/browser.eslintrc"
+    "../../../../../testing/mochitest/browser.eslintrc.js"
   ]
-}
+};

rename from browser/components/newtab/tests/xpcshell/.eslintrc
rename to browser/components/newtab/tests/xpcshell/.eslintrc.js
--- a/browser/components/newtab/tests/xpcshell/.eslintrc
+++ b/browser/components/newtab/tests/xpcshell/.eslintrc.js
@@ -1,5 +1,7 @@
-{
+"use strict";
+
+module.exports = {
   "extends": [
-    "../../../../../testing/xpcshell/xpcshell.eslintrc"
+    "../../../../../testing/xpcshell/xpcshell.eslintrc.js"
   ]
-}
+};

rename from browser/components/originattributes/test/browser/.eslintrc
rename to browser/components/originattributes/test/browser/.eslintrc.js
--- a/browser/components/originattributes/test/browser/.eslintrc
+++ b/browser/components/originattributes/test/browser/.eslintrc.js
@@ -1,5 +1,7 @@
-{
+"use strict";
+
+module.exports = {
   "extends": [
-    "../../../../../testing/mochitest/browser.eslintrc"
+    "../../../../../testing/mochitest/browser.eslintrc.js"
   ]
-}
+};

rename from browser/components/places/tests/browser/.eslintrc
rename to browser/components/places/tests/browser/.eslintrc.js
--- a/browser/components/places/tests/browser/.eslintrc
+++ b/browser/components/places/tests/browser/.eslintrc.js
@@ -1,5 +1,7 @@
-{
+"use strict";
+
+module.exports = {
   "extends": [
-    "../../../../../testing/mochitest/browser.eslintrc"
+    "../../../../../testing/mochitest/browser.eslintrc.js"
   ]
-}
+};

rename from browser/components/places/tests/chrome/.eslintrc
rename to browser/components/places/tests/chrome/.eslintrc.js
--- a/browser/components/places/tests/chrome/.eslintrc
+++ b/browser/components/places/tests/chrome/.eslintrc.js
@@ -1,5 +1,7 @@
-{
+"use strict";
+
+module.exports = {
   "extends": [
-    "../../../../../testing/mochitest/chrome.eslintrc"
+    "../../../../../testing/mochitest/chrome.eslintrc.js"
   ]
-}
+};

rename from browser/components/places/tests/unit/.eslintrc
rename to browser/components/places/tests/unit/.eslintrc.js
--- a/browser/components/places/tests/unit/.eslintrc
+++ b/browser/components/places/tests/unit/.eslintrc.js
@@ -1,5 +1,7 @@
-{
+"use strict";
+
+module.exports = {
   "extends": [
-    "../../../../../testing/xpcshell/xpcshell.eslintrc"
+    "../../../../../testing/xpcshell/xpcshell.eslintrc.js"
   ]
-}
+};

rename from browser/components/preferences/in-content/tests/.eslintrc
rename to browser/components/preferences/in-content/tests/.eslintrc.js
--- a/browser/components/preferences/in-content/tests/.eslintrc
+++ b/browser/components/preferences/in-content/tests/.eslintrc.js
@@ -1,5 +1,7 @@
-{
+"use strict";
+
+module.exports = {
   "extends": [
-    "../../../../../testing/mochitest/browser.eslintrc"
+    "../../../../../testing/mochitest/browser.eslintrc.js"
   ]
-}
+};

rename from browser/components/privatebrowsing/test/browser/.eslintrc
rename to browser/components/privatebrowsing/test/browser/.eslintrc.js
--- a/browser/components/privatebrowsing/test/browser/.eslintrc
+++ b/browser/components/privatebrowsing/test/browser/.eslintrc.js
@@ -1,5 +1,7 @@
-{
+"use strict";
+
+module.exports = {
   "extends": [
-    "../../../../../testing/mochitest/browser.eslintrc"
+    "../../../../../testing/mochitest/browser.eslintrc.js"
   ]
-}
+};

rename from browser/components/safebrowsing/content/test/.eslintrc
rename to browser/components/safebrowsing/content/test/.eslintrc.js
--- a/browser/components/safebrowsing/content/test/.eslintrc
+++ b/browser/components/safebrowsing/content/test/.eslintrc.js
@@ -1,5 +1,7 @@
-{
+"use strict";
+
+module.exports = {
   "extends": [
-    "../../../../../testing/mochitest/browser.eslintrc"
+    "../../../../../testing/mochitest/browser.eslintrc.js"
   ]
-}
+};

rename from browser/components/search/test/.eslintrc
rename to browser/components/search/test/.eslintrc.js
--- a/browser/components/search/test/.eslintrc
+++ b/browser/components/search/test/.eslintrc.js
@@ -1,5 +1,7 @@
-{
+"use strict";
+
+module.exports = {
   "extends": [
-    "../../../../testing/mochitest/browser.eslintrc"
+    "../../../../testing/mochitest/browser.eslintrc.js"
   ]
-}
+};

rename from browser/components/selfsupport/test/.eslintrc
rename to browser/components/selfsupport/test/.eslintrc.js
--- a/browser/components/selfsupport/test/.eslintrc
+++ b/browser/components/selfsupport/test/.eslintrc.js
@@ -1,5 +1,7 @@
-{
+"use strict";
+
+module.exports = {
   "extends": [
-    "../../../../testing/mochitest/browser.eslintrc"
+    "../../../../testing/mochitest/browser.eslintrc.js"
   ]
-}
+};

rename from browser/components/sessionstore/test/.eslintrc
rename to browser/components/sessionstore/test/.eslintrc.js
--- a/browser/components/sessionstore/test/.eslintrc
+++ b/browser/components/sessionstore/test/.eslintrc.js
@@ -1,5 +1,7 @@
-{
+"use strict";
+
+module.exports = {
   "extends": [
-    "../../../../testing/mochitest/browser.eslintrc"
+    "../../../../testing/mochitest/browser.eslintrc.js"
   ]
-}
+};

rename from browser/components/sessionstore/test/unit/.eslintrc
rename to browser/components/sessionstore/test/unit/.eslintrc.js
--- a/browser/components/sessionstore/test/unit/.eslintrc
+++ b/browser/components/sessionstore/test/unit/.eslintrc.js
@@ -1,5 +1,7 @@
-{
+"use strict";
+
+module.exports = {
   "extends": [
-    "../../../../../testing/xpcshell/xpcshell.eslintrc"
+    "../../../../../testing/xpcshell/xpcshell.eslintrc.js"
   ]
-}
+};

rename from browser/components/shell/test/.eslintrc
rename to browser/components/shell/test/.eslintrc.js
--- a/browser/components/shell/test/.eslintrc
+++ b/browser/components/shell/test/.eslintrc.js
@@ -1,5 +1,7 @@
-{
+"use strict";
+
+module.exports = {
   "extends": [
-    "../../../../testing/mochitest/browser.eslintrc"
+    "../../../../testing/mochitest/browser.eslintrc.js"
   ]
-}
+};

rename from browser/components/shell/test/unit/.eslintrc
rename to browser/components/shell/test/unit/.eslintrc.js
--- a/browser/components/shell/test/unit/.eslintrc
+++ b/browser/components/shell/test/unit/.eslintrc.js
@@ -1,5 +1,7 @@
-{
+"use strict";
+
+module.exports = {
   "extends": [
-    "../../../../../testing/xpcshell/xpcshell.eslintrc"
+    "../../../../../testing/xpcshell/xpcshell.eslintrc.js"
   ]
-}
+};

rename from browser/components/tests/browser/.eslintrc
rename to browser/components/tests/browser/.eslintrc.js
--- a/browser/components/tests/browser/.eslintrc
+++ b/browser/components/tests/browser/.eslintrc.js
@@ -1,5 +1,7 @@
-{
+"use strict";
+
+module.exports = {
   "extends": [
-    "../../../../testing/mochitest/browser.eslintrc"
+    "../../../../testing/mochitest/browser.eslintrc.js"
   ]
-}
+};

rename from browser/components/translation/test/.eslintrc
rename to browser/components/translation/test/.eslintrc.js
--- a/browser/components/translation/test/.eslintrc
+++ b/browser/components/translation/test/.eslintrc.js
@@ -1,5 +1,7 @@
-{
+"use strict";
+
+module.exports = {
   "extends": [
-    "../../../../testing/mochitest/browser.eslintrc"
+    "../../../../testing/mochitest/browser.eslintrc.js"
   ]
-}
+};

rename from browser/components/translation/test/unit/.eslintrc
rename to browser/components/translation/test/unit/.eslintrc.js
--- a/browser/components/translation/test/unit/.eslintrc
+++ b/browser/components/translation/test/unit/.eslintrc.js
@@ -1,5 +1,7 @@
-{
+"use strict";
+
+module.exports = {
   "extends": [
-    "../../../../../testing/xpcshell/xpcshell.eslintrc"
+    "../../../../../testing/xpcshell/xpcshell.eslintrc.js"
   ]
-}
+};

rename from browser/components/uitour/test/.eslintrc
rename to browser/components/uitour/test/.eslintrc.js
--- a/browser/components/uitour/test/.eslintrc
+++ b/browser/components/uitour/test/.eslintrc.js
@@ -1,5 +1,7 @@
-{
+"use strict";
+
+module.exports = {
   "extends": [
-    "../../../../testing/mochitest/browser.eslintrc"
+    "../../../../testing/mochitest/browser.eslintrc.js"
   ]
-}
+};

rename from browser/experiments/test/xpcshell/.eslintrc
rename to browser/experiments/test/xpcshell/.eslintrc.js
--- a/browser/experiments/test/xpcshell/.eslintrc
+++ b/browser/experiments/test/xpcshell/.eslintrc.js
@@ -1,5 +1,7 @@
-{
+"use strict";
+
+module.exports = {
   "extends": [
-    "../../../../testing/xpcshell/xpcshell.eslintrc"
+    "../../../../testing/xpcshell/xpcshell.eslintrc.js"
   ]
-}
+};

rename from browser/extensions/formautofill/.eslintrc
rename to browser/extensions/formautofill/.eslintrc.js
--- a/browser/extensions/formautofill/.eslintrc
+++ b/browser/extensions/formautofill/.eslintrc.js
@@ -1,10 +1,12 @@
-{
-  "extends": "../../.eslintrc",
+"use strict";
+
+module.exports = { // eslint-disable-line no-undef
+  "extends": "../../.eslintrc.js",
 
   "globals": {
     "Components": true,
     "dump": true,
     "TextDecoder": false,
     "TextEncoder": false,
   },
 
@@ -328,17 +330,17 @@
 
     // Allow the use of leading or trailing decimal points in numeric literals.
     "no-floating-decimal": 0,
 
     // Allow comments inline after code.
     "no-inline-comments": 0,
 
     // Disallow use of labels for anything other then loops and switches.
-    "no-labels": [2, { "allowLoop": true }],
+    "no-labels": [2, {"allowLoop": true}],
 
     // Disallow use of multiline strings (use template strings instead).
     "no-multi-str": 1,
 
     // Disallow multiple empty lines.
     "no-multiple-empty-lines": [1, {"max": 2}],
 
     // Allow reassignment of function parameters.
@@ -464,10 +466,10 @@
     // Disallow usage of __iterator__ property
     "no-iterator": 2,
 
     // Disallow labels that share a name with a variable
     "no-label-var": 2,
 
     // Disallow creating new instances of String, Number, and Boolean
     "no-new-wrappers": 2,
-  }
-}
+  },
+};

rename from browser/extensions/formautofill/test/browser/.eslintrc
rename to browser/extensions/formautofill/test/browser/.eslintrc.js
--- a/browser/extensions/formautofill/test/browser/.eslintrc
+++ b/browser/extensions/formautofill/test/browser/.eslintrc.js
@@ -1,5 +1,7 @@
-{
+"use strict";
+
+module.exports = { // eslint-disable-line no-undef
   "extends": [
-    "../../../../../testing/mochitest/browser.eslintrc"
-  ]
-}
+    "../../../../../testing/mochitest/browser.eslintrc.js",
+  ],
+};

rename from browser/extensions/pdfjs/test/.eslintrc
rename to browser/extensions/pdfjs/test/.eslintrc.js
--- a/browser/extensions/pdfjs/test/.eslintrc
+++ b/browser/extensions/pdfjs/test/.eslintrc.js
@@ -1,5 +1,7 @@
-{
+"use strict";
+
+module.exports = {
   "extends": [
-    "../../../../testing/mochitest/browser.eslintrc"
+    "../../../../testing/mochitest/browser.eslintrc.js"
   ]
-}
+};

rename from browser/modules/test/.eslintrc
rename to browser/modules/test/.eslintrc.js
--- a/browser/modules/test/.eslintrc
+++ b/browser/modules/test/.eslintrc.js
@@ -1,5 +1,7 @@
-{
+"use strict";
+
+module.exports = {
   "extends": [
-    "../../../testing/mochitest/browser.eslintrc"
+    "../../../testing/mochitest/browser.eslintrc.js"
   ]
-}
+};

rename from browser/modules/test/unit/social/.eslintrc
rename to browser/modules/test/unit/social/.eslintrc.js
--- a/browser/modules/test/unit/social/.eslintrc
+++ b/browser/modules/test/unit/social/.eslintrc.js
@@ -1,5 +1,7 @@
-{
+"use strict";
+
+module.exports = {
   "extends": [
-    "../../../../../testing/xpcshell/xpcshell.eslintrc"
+    "../../../../../testing/xpcshell/xpcshell.eslintrc.js"
   ]
-}
+};

rename from browser/modules/test/xpcshell/.eslintrc
rename to browser/modules/test/xpcshell/.eslintrc.js
--- a/browser/modules/test/xpcshell/.eslintrc
+++ b/browser/modules/test/xpcshell/.eslintrc.js
@@ -1,5 +1,7 @@
-{
+"use strict";
+
+module.exports = {
   "extends": [
-    "../../../../testing/xpcshell/xpcshell.eslintrc"
+    "../../../../testing/xpcshell/xpcshell.eslintrc.js"
   ]
-}
+};

rename from devtools/.eslintrc
rename to devtools/.eslintrc.js
--- a/devtools/.eslintrc
+++ b/devtools/.eslintrc.js
@@ -1,9 +1,11 @@
-{
+"use strict";
+
+module.exports = {
   "plugins": [
     "react"
   ],
   "globals": {
     "atob": true,
     "btoa": true,
     "Components": true,
     "CSSRule": true,
@@ -146,17 +148,20 @@
     // Enforces spacing between keys and values in object literal properties.
     "key-spacing": [2, {"beforeColon": false, "afterColon": true}],
     // Allow mixed 'LF' and 'CRLF' as linebreaks.
     "linebreak-style": 0,
     // Don't enforce the maximum depth that blocks can be nested. The complexity
     // rule is a better rule to check this.
     "max-depth": 0,
     // Maximum length of a line.
-    "max-len": [2, 90, 2, {"ignoreUrls": true, "ignorePattern": "data:image\/|\\s*require\\s*\\(|^\\s*loader\\.lazy|-\\*-"}],
+    "max-len": [2, 90, 2, {
+      "ignoreUrls": true,
+      "ignorePattern": "data:image\/|\\s*require\\s*\\(|^\\s*loader\\.lazy|-\\*-"
+    }],
     // Maximum depth callbacks can be nested.
     "max-nested-callbacks": [2, 3],
     // Don't limit the number of parameters that can be used in a function.
     "max-params": 0,
     // Don't limit the maximum number of statement allowed in a function. We
     // already have the complexity rule that's a better measurement.
     "max-statements": 0,
     // Require a capital letter for constructors, only check if all new
@@ -317,17 +322,18 @@
     "no-underscore-dangle": 0,
     // Allow use of undefined variable.
     "no-undefined": 0,
     // Disallow the use of Boolean literals in conditional expressions.
     "no-unneeded-ternary": 2,
     // Disallow unreachable statements after a return, throw, continue, or break
     // statement.
     "no-unreachable": 2,
-    // Disallow global and local variables that aren't used, but allow unused function arguments.
+    // Disallow global and local variables that aren't used, but allow unused
+    // function arguments.
     "no-unused-vars": [2, {"vars": "all", "args": "none"}],
     // Allow using variables before they are defined.
     "no-use-before-define": 0,
     // We use var-only-at-top-level instead of no-var as we allow top level
     // vars.
     "no-var": 0,
     // Allow using TODO/FIXME comments.
     "no-warning-comments": 0,
@@ -460,9 +466,9 @@
     // disallow wrapping of non-IIFE statements in parens
     "no-wrap-func": 0,
     // require assignment operator shorthand where possible or prohibit it
     // entirely
     "operator-assignment": 0,
     // enforce operators to be placed before or after line breaks
     "operator-linebreak": 0,
   }
-}
+};

rename from devtools/.eslintrc.mochitests
rename to devtools/.eslintrc.mochitests.js
--- a/devtools/.eslintrc.mochitests
+++ b/devtools/.eslintrc.mochitests.js
@@ -1,20 +1,20 @@
 // Parent config file for all devtools browser mochitest files.
-{
+module.exports = {
   "extends": [
-    "../testing/mochitest/browser.eslintrc"
+    "../testing/mochitest/browser.eslintrc.js"
   ],
   // All globals made available in the test environment.
   "globals": {
     "DevToolsUtils": true,
     "gDevTools": true,
     "once": true,
     "synthesizeKeyFromKeyTag": true,
     "TargetFactory": true,
     "waitForTick": true,
   },
 
   "rules": {
     // Tests can always import anything.
     "mozilla/reject-some-requires": 0,
   },
-}
+};

rename from devtools/.eslintrc.xpcshell
rename to devtools/.eslintrc.xpcshell.js
--- a/devtools/.eslintrc.xpcshell
+++ b/devtools/.eslintrc.xpcshell.js
@@ -1,21 +1,21 @@
 // Parent config file for all devtools xpcshell files.
-{
+module.exports = {
   "extends": [
-    "../testing/xpcshell/xpcshell.eslintrc"
+    "../testing/xpcshell/xpcshell.eslintrc.js"
   ],
   "rules": {
     // Allow non-camelcase so that run_test doesn't produce a warning.
     "camelcase": 0,
     // Allow using undefined variables so that tests can refer to functions
     // and variables defined in head.js files, without having to maintain a
     // list of globals in each .eslintrc file.
     // Note that bug 1168340 will eventually help auto-registering globals
     // from head.js files.
     "no-undef": 0,
     "block-scoped-var": 0,
     // Allow run_test to be unused in xpcshell
     "no-unused-vars": [2, { "varsIgnorePattern": "run_test" }],
     // Tests can always import anything.
     "mozilla/reject-some-requires": 0,
   }
-}
+};

rename from devtools/client/aboutdebugging/test/.eslintrc
rename to devtools/client/aboutdebugging/test/.eslintrc.js
--- a/devtools/client/aboutdebugging/test/.eslintrc
+++ b/devtools/client/aboutdebugging/test/.eslintrc.js
@@ -1,11 +1,13 @@
-{
+"use strict";
+
+module.exports = {
   // Extend from the shared list of defined globals for mochitests.
-  "extends": "../../../.eslintrc.mochitests",
+  "extends": "../../../.eslintrc.mochitests.js",
   // All globals made available in aboutdebugging head.js file.
   "globals": {
     "AddonManager": true,
     "addTab": true,
     "assertHasTarget": true,
     "CHROME_ROOT": true,
     "changeAboutDebuggingHash": true,
     "closeAboutDebugging": true,
@@ -16,9 +18,9 @@
     "openPanel": true,
     "removeTab": true,
     "uninstallAddon": true,
     "unregisterServiceWorker": true,
     "waitForInitialAddonList": true,
     "waitForMutation": true,
     "waitForServiceWorkerRegistered": true
   }
-}
+};

rename from devtools/client/animationinspector/test/.eslintrc
rename to devtools/client/animationinspector/test/.eslintrc.js
--- a/devtools/client/animationinspector/test/.eslintrc
+++ b/devtools/client/animationinspector/test/.eslintrc.js
@@ -1,4 +1,6 @@
-{
+"use strict";
+
+module.exports = {
   // Extend from the shared list of defined globals for mochitests.
-  "extends": "../../../.eslintrc.mochitests"
-}
+  "extends": "../../../.eslintrc.mochitests.js"
+};

rename from devtools/client/animationinspector/test/unit/.eslintrc
rename to devtools/client/animationinspector/test/unit/.eslintrc.js
--- a/devtools/client/animationinspector/test/unit/.eslintrc
+++ b/devtools/client/animationinspector/test/unit/.eslintrc.js
@@ -1,4 +1,6 @@
-{
+"use strict";
+
+module.exports = {
   // Extend from the common devtools xpcshell eslintrc config.
-  "extends": "../../../../.eslintrc.xpcshell"
-}
\ No newline at end of file
+  "extends": "../../../../.eslintrc.xpcshell.js"
+};

rename from devtools/client/canvasdebugger/test/.eslintrc
rename to devtools/client/canvasdebugger/test/.eslintrc.js
--- a/devtools/client/canvasdebugger/test/.eslintrc
+++ b/devtools/client/canvasdebugger/test/.eslintrc.js
@@ -1,4 +1,6 @@
-{
+"use strict";
+
+module.exports = {
   // Extend from the shared list of defined globals for mochitests.
-  "extends": "../../../.eslintrc.mochitests"
-}
+  "extends": "../../../.eslintrc.mochitests.js"
+};

rename from devtools/client/commandline/test/.eslintrc
rename to devtools/client/commandline/test/.eslintrc.js
--- a/devtools/client/commandline/test/.eslintrc
+++ b/devtools/client/commandline/test/.eslintrc.js
@@ -1,8 +1,10 @@
-{
+"use strict";
+
+module.exports = {
   // Extend from the shared list of defined globals for mochitests.
-  "extends": "../../../.eslintrc.mochitests",
+  "extends": "../../../.eslintrc.mochitests.js",
   "globals": {
     "helpers": true,
     "assert": true
   }
-}
+};

rename from devtools/client/debugger/new/test/mochitest/.eslintrc
rename to devtools/client/debugger/new/test/mochitest/.eslintrc.js
--- a/devtools/client/debugger/new/test/mochitest/.eslintrc
+++ b/devtools/client/debugger/new/test/mochitest/.eslintrc.js
@@ -1,9 +1,11 @@
-{
+"use strict";
+
+module.exports = {
   "globals": {
     "add_task": false,
     "Assert": false,
     "BrowserTestUtils": false,
     "content": false,
     "ContentTask": false,
     "ContentTaskUtils": false,
     "EventUtils": false,
@@ -65,9 +67,9 @@
     "addBreakpoint": false,
     "toggleCallStack": false,
     "isVisibleWithin": false,
     "clickElement": false,
     "togglePauseOnExceptions": false,
     "pressKey": false,
     "EXAMPLE_URL": false
   }
-}
+};

rename from devtools/client/debugger/test/.eslintrc
rename to devtools/client/debugger/test/.eslintrc.js
--- a/devtools/client/debugger/test/.eslintrc
+++ b/devtools/client/debugger/test/.eslintrc.js
@@ -1,4 +1,6 @@
-{
+"use strict";
+
+module.exports = {
   // Extend from the shared list of defined globals for mochitests.
-  "extends": "../../../.eslintrc.mochitests"
-}
+  "extends": "../../../.eslintrc.mochitests.js"
+};

rename from devtools/client/dom/.eslintrc
rename to devtools/client/dom/.eslintrc.js
--- a/devtools/client/dom/.eslintrc
+++ b/devtools/client/dom/.eslintrc.js
@@ -1,15 +1,17 @@
-{
+"use strict";
+
+module.exports = {
   "globals": {
     "XMLHttpRequest": true,
     "window": true,
     "define": true,
     "addEventListener": true,
     "document": true,
     "dispatchEvent": true,
     "MessageEvent": true
   },
   "rules": {
     "indent": 0,
     "padded-blocks": 0,
   }
-}
+};

rename from devtools/client/dom/test/.eslintrc
rename to devtools/client/dom/test/.eslintrc.js
--- a/devtools/client/dom/test/.eslintrc
+++ b/devtools/client/dom/test/.eslintrc.js
@@ -1,4 +1,6 @@
-{
+"use strict";
+
+module.exports = {
   // Extend from the shared list of defined globals for mochitests.
-  "extends": "../../../.eslintrc.mochitests",
-}
+  "extends": "../../../.eslintrc.mochitests.js",
+};

rename from devtools/client/framework/test/.eslintrc
rename to devtools/client/framework/test/.eslintrc.js
--- a/devtools/client/framework/test/.eslintrc
+++ b/devtools/client/framework/test/.eslintrc.js
@@ -1,4 +1,6 @@
-{
+"use strict";
+
+module.exports = {
   // Extend from the shared list of defined globals for mochitests.
-  "extends": "../../../.eslintrc.mochitests"
-}
+  "extends": "../../../.eslintrc.mochitests.js"
+};

rename from devtools/client/inspector/.eslintrc
rename to devtools/client/inspector/.eslintrc.js
--- a/devtools/client/inspector/.eslintrc
+++ b/devtools/client/inspector/.eslintrc.js
@@ -1,12 +1,15 @@
-{
+"use strict";
+
+module.exports = {
   // Extend from the devtools eslintrc.
-  "extends": "../../.eslintrc",
+  "extends": "../../.eslintrc.js",
 
   "rules": {
     // The inspector is being migrated to HTML and cleaned of
     // chrome-privileged code, so this rule disallows requiring chrome
     // code. Some files in the inspector disable this rule still. The
     // goal is to enable the rule globally on all files.
+    /* eslint-disable max-len */
     "mozilla/reject-some-requires": [2, "^(chrome|chrome:.*|resource:.*|devtools/server/.*|.*\\.jsm|devtools/shared/platform/(chome|content)/.*)$"],
   },
-}
+};

rename from devtools/client/inspector/components/test/.eslintrc
rename to devtools/client/inspector/components/test/.eslintrc.js
--- a/devtools/client/inspector/components/test/.eslintrc
+++ b/devtools/client/inspector/components/test/.eslintrc.js
@@ -1,4 +1,6 @@
-{
+"use strict";
+
+module.exports = {
   // Extend from the shared list of defined globals for mochitests.
-  "extends": "../../../../.eslintrc.mochitests"
-}
+  "extends": "../../../../.eslintrc.mochitests.js"
+};

rename from devtools/client/inspector/computed/test/.eslintrc
rename to devtools/client/inspector/computed/test/.eslintrc.js
--- a/devtools/client/inspector/computed/test/.eslintrc
+++ b/devtools/client/inspector/computed/test/.eslintrc.js
@@ -1,4 +1,6 @@
-{
+"use strict";
+
+module.exports = {
   // Extend from the shared list of defined globals for mochitests.
-  "extends": "../../../../.eslintrc.mochitests"
-}
+  "extends": "../../../../.eslintrc.mochitests.js"
+};

rename from devtools/client/inspector/fonts/test/.eslintrc
rename to devtools/client/inspector/fonts/test/.eslintrc.js
--- a/devtools/client/inspector/fonts/test/.eslintrc
+++ b/devtools/client/inspector/fonts/test/.eslintrc.js
@@ -1,4 +1,6 @@
-{
+"use strict";
+
+module.exports = {
   // Extend from the shared list of defined globals for mochitests.
-  "extends": "../../../../.eslintrc.mochitests"
-}
+  "extends": "../../../../.eslintrc.mochitests.js"
+};

rename from devtools/client/inspector/markup/test/.eslintrc
rename to devtools/client/inspector/markup/test/.eslintrc.js
--- a/devtools/client/inspector/markup/test/.eslintrc
+++ b/devtools/client/inspector/markup/test/.eslintrc.js
@@ -1,4 +1,6 @@
-{
+"use strict";
+
+module.exports = {
   // Extend from the shared list of defined globals for mochitests.
-  "extends": "../../../../.eslintrc.mochitests"
-}
+  "extends": "../../../../.eslintrc.mochitests.js"
+};

rename from devtools/client/inspector/rules/test/.eslintrc
rename to devtools/client/inspector/rules/test/.eslintrc.js
--- a/devtools/client/inspector/rules/test/.eslintrc
+++ b/devtools/client/inspector/rules/test/.eslintrc.js
@@ -1,4 +1,6 @@
-{
+"use strict";
+
+module.exports = {
   // Extend from the shared list of defined globals for mochitests.
-  "extends": "../../../../.eslintrc.mochitests"
-}
+  "extends": "../../../../.eslintrc.mochitests.js"
+};

rename from devtools/client/inspector/shared/test/.eslintrc
rename to devtools/client/inspector/shared/test/.eslintrc.js
--- a/devtools/client/inspector/shared/test/.eslintrc
+++ b/devtools/client/inspector/shared/test/.eslintrc.js
@@ -1,4 +1,6 @@
-{
+"use strict";
+
+module.exports = {
   // Extend from the shared list of defined globals for mochitests.
-  "extends": "../../../../.eslintrc.mochitests"
-}
+  "extends": "../../../../.eslintrc.mochitests.js"
+};

rename from devtools/client/inspector/test/.eslintrc
rename to devtools/client/inspector/test/.eslintrc.js
--- a/devtools/client/inspector/test/.eslintrc
+++ b/devtools/client/inspector/test/.eslintrc.js
@@ -1,4 +1,6 @@
-{
+"use strict";
+
+module.exports = {
   // Extend from the shared list of defined globals for mochitests.
-  "extends": "../../../.eslintrc.mochitests"
-}
+  "extends": "../../../.eslintrc.mochitests.js"
+};

rename from devtools/client/jsonview/.eslintrc
rename to devtools/client/jsonview/.eslintrc.js
--- a/devtools/client/jsonview/.eslintrc
+++ b/devtools/client/jsonview/.eslintrc.js
@@ -1,9 +1,11 @@
-{
+"use strict";
+
+module.exports = {
   "globals": {
     "define": true,
     "document": true,
     "window": true,
     "CustomEvent": true,
     "Locale": true
   }
-}
+};

rename from devtools/client/jsonview/test/.eslintrc
rename to devtools/client/jsonview/test/.eslintrc.js
--- a/devtools/client/jsonview/test/.eslintrc
+++ b/devtools/client/jsonview/test/.eslintrc.js
@@ -1,4 +1,6 @@
-{
+"use strict";
+
+module.exports = {
   // Extend from the shared list of defined globals for mochitests.
-  "extends": "../../../.eslintrc.mochitests"
-}
+  "extends": "../../../.eslintrc.mochitests.js"
+};

rename from devtools/client/memory/test/browser/.eslintrc
rename to devtools/client/memory/test/browser/.eslintrc.js
--- a/devtools/client/memory/test/browser/.eslintrc
+++ b/devtools/client/memory/test/browser/.eslintrc.js
@@ -1,4 +1,6 @@
-{
+"use strict";
+
+module.exports = {
   // Extend from the shared list of defined globals for mochitests.
-  "extends": "../../../../.eslintrc.mochitests"
-}
+  "extends": "../../../../.eslintrc.mochitests.js"
+};

rename from devtools/client/memory/test/unit/.eslintrc
rename to devtools/client/memory/test/unit/.eslintrc.js
--- a/devtools/client/memory/test/unit/.eslintrc
+++ b/devtools/client/memory/test/unit/.eslintrc.js
@@ -1,4 +1,6 @@
-{
+"use strict";
+
+module.exports = {
   // Extend from the shared list of defined globals for mochitests.
-  "extends": "../../../../.eslintrc.xpcshell"
-}
+  "extends": "../../../../.eslintrc.xpcshell.js"
+};

rename from devtools/client/netmonitor/.eslintrc
rename to devtools/client/netmonitor/.eslintrc.js
--- a/devtools/client/netmonitor/.eslintrc
+++ b/devtools/client/netmonitor/.eslintrc.js
@@ -1,12 +1,15 @@
-{
+"use strict";
+
+module.exports = {
   // Extend from the devtools eslintrc.
-  "extends": "../../.eslintrc",
+  "extends": "../../.eslintrc.js",
 
   "rules": {
     // The netmonitor is being migrated to HTML and cleaned of
     // chrome-privileged code, so this rule disallows requiring chrome
     // code. Some files in the netmonitor disable this rule still. The
     // goal is to enable the rule globally on all files.
+    /* eslint-disable max-len */
     "mozilla/reject-some-requires": [2, "^(chrome|chrome:.*|resource:.*|devtools/server/.*|.*\\.jsm|devtools/shared/platform/(chome|content)/.*)$"],
   },
-}
+};

rename from devtools/client/netmonitor/har/test/.eslintrc
rename to devtools/client/netmonitor/har/test/.eslintrc.js
--- a/devtools/client/netmonitor/har/test/.eslintrc
+++ b/devtools/client/netmonitor/har/test/.eslintrc.js
@@ -1,4 +1,6 @@
-{
+"use strict";
+
+module.exports = {
   // Extend from the shared list of defined globals for mochitests.
-  "extends": "../../../../.eslintrc.mochitests"
-}
+  "extends": "../../../../.eslintrc.mochitests.js"
+};

rename from devtools/client/netmonitor/test/.eslintrc
rename to devtools/client/netmonitor/test/.eslintrc.js
--- a/devtools/client/netmonitor/test/.eslintrc
+++ b/devtools/client/netmonitor/test/.eslintrc.js
@@ -1,4 +1,6 @@
-{
+"use strict";
+
+module.exports = {
   // Extend from the shared list of defined globals for mochitests.
-  "extends": "../../../.eslintrc.mochitests"
-}
+  "extends": "../../../.eslintrc.mochitests.js"
+};

rename from devtools/client/performance/test/.eslintrc
rename to devtools/client/performance/test/.eslintrc.js
--- a/devtools/client/performance/test/.eslintrc
+++ b/devtools/client/performance/test/.eslintrc.js
@@ -1,4 +1,6 @@
-{
+"use strict";
+
+module.exports = {
   // Extend from the shared list of defined globals for mochitests.
-  "extends": "../../../.eslintrc.mochitests"
-}
+  "extends": "../../../.eslintrc.mochitests.js"
+};

rename from devtools/client/performance/test/unit/.eslintrc
rename to devtools/client/performance/test/unit/.eslintrc.js
--- a/devtools/client/performance/test/unit/.eslintrc
+++ b/devtools/client/performance/test/unit/.eslintrc.js
@@ -1,4 +1,6 @@
-{
+"use strict";
+
+module.exports = {
   // Extend from the shared list of defined globals for mochitests.
-  "extends": "../../../../.eslintrc.xpcshell"
-}
+  "extends": "../../../../.eslintrc.xpcshell.js"
+};

rename from devtools/client/projecteditor/test/.eslintrc
rename to devtools/client/projecteditor/test/.eslintrc.js
--- a/devtools/client/projecteditor/test/.eslintrc
+++ b/devtools/client/projecteditor/test/.eslintrc.js
@@ -1,4 +1,6 @@
-{
+"use strict";
+
+module.exports = {
   // Extend from the shared list of defined globals for mochitests.
-  "extends": "../../../.eslintrc.mochitests"
-}
+  "extends": "../../../.eslintrc.mochitests.js"
+};

rename from devtools/client/promisedebugger/test/.eslintrc
rename to devtools/client/promisedebugger/test/.eslintrc.js
--- a/devtools/client/promisedebugger/test/.eslintrc
+++ b/devtools/client/promisedebugger/test/.eslintrc.js
@@ -1,4 +1,6 @@
-{
+"use strict";
+
+module.exports = {
   // Extend from the shared list of defined globals for mochitests.
-  "extends": "../../../.eslintrc.mochitests"
-}
+  "extends": "../../../.eslintrc.mochitests.js"
+};

rename from devtools/client/responsive.html/test/browser/.eslintrc
rename to devtools/client/responsive.html/test/browser/.eslintrc.js
--- a/devtools/client/responsive.html/test/browser/.eslintrc
+++ b/devtools/client/responsive.html/test/browser/.eslintrc.js
@@ -1,4 +1,6 @@
-{
+"use strict";
+
+module.exports = {
   // Extend from the shared list of defined globals for mochitests.
-  "extends": "../../../../.eslintrc.mochitests"
-}
+  "extends": "../../../../.eslintrc.mochitests.js"
+};

rename from devtools/client/responsive.html/test/unit/.eslintrc
rename to devtools/client/responsive.html/test/unit/.eslintrc.js
--- a/devtools/client/responsive.html/test/unit/.eslintrc
+++ b/devtools/client/responsive.html/test/unit/.eslintrc.js
@@ -1,4 +1,6 @@
-{
+"use strict";
+
+module.exports = {
   // Extend from the shared list of defined globals for xpcshell.
-  "extends": "../../../../.eslintrc.xpcshell"
-}
+  "extends": "../../../../.eslintrc.xpcshell.js"
+};

rename from devtools/client/responsivedesign/test/.eslintrc
rename to devtools/client/responsivedesign/test/.eslintrc.js
--- a/devtools/client/responsivedesign/test/.eslintrc
+++ b/devtools/client/responsivedesign/test/.eslintrc.js
@@ -1,8 +1,10 @@
-{
+"use strict";
+
+module.exports = {
   // Extend from the shared list of defined globals for mochitests.
-  "extends": "../../../.eslintrc.mochitests",
+  "extends": "../../../.eslintrc.mochitests.js",
   "globals": {
     "ResponsiveUI": true,
     "helpers": true
   }
-}
+};

rename from devtools/client/scratchpad/test/.eslintrc
rename to devtools/client/scratchpad/test/.eslintrc.js
--- a/devtools/client/scratchpad/test/.eslintrc
+++ b/devtools/client/scratchpad/test/.eslintrc.js
@@ -1,4 +1,6 @@
-{
+"use strict";
+
+module.exports = {
   // Extend from the shared list of defined globals for mochitests.
-  "extends": "../../../.eslintrc.mochitests"
-}
+  "extends": "../../../.eslintrc.mochitests.js"
+};

rename from devtools/client/shadereditor/test/.eslintrc
rename to devtools/client/shadereditor/test/.eslintrc.js
--- a/devtools/client/shadereditor/test/.eslintrc
+++ b/devtools/client/shadereditor/test/.eslintrc.js
@@ -1,4 +1,6 @@
-{
+"use strict";
+
+module.exports = {
   // Extend from the shared list of defined globals for mochitests.
-  "extends": "../../../.eslintrc.mochitests"
-}
+  "extends": "../../../.eslintrc.mochitests.js"
+};

rename from devtools/client/shared/components/.eslintrc
rename to devtools/client/shared/components/.eslintrc.js
--- a/devtools/client/shared/components/.eslintrc
+++ b/devtools/client/shared/components/.eslintrc.js
@@ -1,5 +1,7 @@
-{
+"use strict";
+
+module.exports = {
   "globals": {
     "define": true,
   }
-}
+};

rename from devtools/client/shared/components/test/browser/.eslintrc
rename to devtools/client/shared/components/test/browser/.eslintrc.js
--- a/devtools/client/shared/components/test/browser/.eslintrc
+++ b/devtools/client/shared/components/test/browser/.eslintrc.js
@@ -1,4 +1,6 @@
-{
+"use strict";
+
+module.exports = {
   // Extend from the shared list of defined globals for mochitests.
-  "extends": "../../../../../.eslintrc.mochitests",
-}
+  "extends": "../../../../../.eslintrc.mochitests.js",
+};

rename from devtools/client/shared/components/test/mochitest/.eslintrc
rename to devtools/client/shared/components/test/mochitest/.eslintrc.js
--- a/devtools/client/shared/components/test/mochitest/.eslintrc
+++ b/devtools/client/shared/components/test/mochitest/.eslintrc.js
@@ -1,4 +1,6 @@
-{
+"use strict";
+
+module.exports = {
   // Extend from the shared list of defined globals for mochitests.
-  "extends": "../../../../../.eslintrc.mochitests"
-}
+  "extends": "../../../../../.eslintrc.mochitests.js"
+};

rename from devtools/client/shared/shim/test/.eslintrc
rename to devtools/client/shared/shim/test/.eslintrc.js
--- a/devtools/client/shared/shim/test/.eslintrc
+++ b/devtools/client/shared/shim/test/.eslintrc.js
@@ -1,4 +1,6 @@
-{
+"use strict";
+
+module.exports = {
   // Extend from the shared list of defined globals for mochitests.
-  "extends": "../../../../.eslintrc.mochitests"
-}
+  "extends": "../../../../.eslintrc.mochitests.js"
+};

rename from devtools/client/shared/test/.eslintrc
rename to devtools/client/shared/test/.eslintrc.js
--- a/devtools/client/shared/test/.eslintrc
+++ b/devtools/client/shared/test/.eslintrc.js
@@ -1,4 +1,6 @@
-{
+"use strict";
+
+module.exports = {
   // Extend from the shared list of defined globals for mochitests.
-  "extends": "../../../.eslintrc.mochitests"
-}
+  "extends": "../../../.eslintrc.mochitests.js"
+};

rename from devtools/client/shared/test/unit/.eslintrc
rename to devtools/client/shared/test/unit/.eslintrc.js
--- a/devtools/client/shared/test/unit/.eslintrc
+++ b/devtools/client/shared/test/unit/.eslintrc.js
@@ -1,4 +1,6 @@
-{
+"use strict";
+
+module.exports = {
   // Extend from the common devtools xpcshell eslintrc config.
-  "extends": "../../../../.eslintrc.xpcshell"
-}
\ No newline at end of file
+  "extends": "../../../../.eslintrc.xpcshell.js"
+};

rename from devtools/client/sourceeditor/.eslintrc
rename to devtools/client/sourceeditor/.eslintrc.js
--- a/devtools/client/sourceeditor/.eslintrc
+++ b/devtools/client/sourceeditor/.eslintrc.js
@@ -1,12 +1,15 @@
-{
+"use strict";
+
+module.exports = {
   // Extend from the devtools eslintrc.
-  "extends": "../../.eslintrc",
+  "extends": "../../.eslintrc.js",
 
   "rules": {
     // The inspector is being migrated to HTML and cleaned of
     // chrome-privileged code, so this rule disallows requiring chrome
     // code. Some files here disable this rule still. The
     // goal is to enable the rule globally on all files.
+    /* eslint-disable max-len */
     "mozilla/reject-some-requires": [2, "^(chrome|chrome:.*|resource:.*|devtools/server/.*|.*\\.jsm)$"],
   },
-}
+};

rename from devtools/client/sourceeditor/test/.eslintrc
rename to devtools/client/sourceeditor/test/.eslintrc.js
--- a/devtools/client/sourceeditor/test/.eslintrc
+++ b/devtools/client/sourceeditor/test/.eslintrc.js
@@ -1,4 +1,6 @@
-{
+"use strict";
+
+module.exports = {
   // Extend from the shared list of defined globals for mochitests.
-  "extends": "../../../.eslintrc.mochitests"
-}
+  "extends": "../../../.eslintrc.mochitests.js"
+};