diff --git a/editor/composer/test/.eslintrc.js b/editor/composer/test/.eslintrc.js
new file mode 100644
index 000000000000..72e9f47221b8
--- /dev/null
+++ b/editor/composer/test/.eslintrc.js
@@ -0,0 +1,8 @@
+"use strict";
+
+module.exports = {
+  "extends": [
+    "plugin:mozilla/chrome-test",
+    "plugin:mozilla/mochitest-test",
+  ]
+};
diff --git a/editor/libeditor/tests/.eslintrc.js b/editor/libeditor/tests/.eslintrc.js
new file mode 100644
index 000000000000..6746617eebd0
--- /dev/null
+++ b/editor/libeditor/tests/.eslintrc.js
@@ -0,0 +1,8 @@
+"use strict";
+
+module.exports = {
+  "extends": [
+    "plugin:mozilla/browser-test",
+    "plugin:mozilla/mochitest-test",
+  ]
+};
diff --git a/editor/libeditor/tests/test_resizers_resizing_elements.html b/editor/libeditor/tests/test_resizers_resizing_elements.html
index 91727be19666..a929e1a7e27b 100644
--- a/editor/libeditor/tests/test_resizers_resizing_elements.html
+++ b/editor/libeditor/tests/test_resizers_resizing_elements.html
@@ -118,6 +118,8 @@ SimpleTest.waitForFocus(async function() {
     const needlessGrowth = aPreserveRatio ? 1 : 0;
     const reversedGrowth = aPreserveRatio ? -1 : 1;
 
+    /* eslint-disable no-multi-spaces */
+
     // top resizer
     await testResizer(W/2,   0, -10, -10,   0,  10);
     await testResizer(W/2,   0, -10,   0,   0,   0);
@@ -205,6 +207,8 @@ SimpleTest.waitForFocus(async function() {
     await testResizer(  0,   0,  10, -10, -10 * reversedGrowth,  10);
     await testResizer(  0,   0,  10,   0, -10 * ignoredGrowth,   0);
     await testResizer(  0,   0,  10,  10, -10, -10);
+
+    /* eslint-enable no-multi-spaces */
   }
 
   const kTests = [
@@ -227,7 +231,7 @@ SimpleTest.waitForFocus(async function() {
 
   // Resizers for absolute positioned element and table element are available
   // only when enableAbsolutePositionEditing or enableInlineTableEditing is
-  // enabled for each.  So, let's enable them during testing resizers for 
+  // enabled for each.  So, let's enable them during testing resizers for
   // absolute positioned elements or table elements.
   await SpecialPowers.pushPrefEnv({"set": [["editor.resizing.preserve_ratio", false]]});
   for (const kTest of kTests) {
diff --git a/editor/spellchecker/tests/.eslintrc.js b/editor/spellchecker/tests/.eslintrc.js
new file mode 100644
index 000000000000..8c8be53cd53d
--- /dev/null
+++ b/editor/spellchecker/tests/.eslintrc.js
@@ -0,0 +1,7 @@
+"use strict";
+
+module.exports = {
+  "extends": [
+    "plugin:mozilla/mochitest-test"
+  ]
+};