4 files changed, 4 insertions, 4 deletions
diff --git a/parser/htmlparser/tests/mochitest/parser_datreader.js b/parser/htmlparser/tests/mochitest/parser_datreader.js
index d3d3ea2c89..081e326724 100644
--- a/parser/htmlparser/tests/mochitest/parser_datreader.js
+++ b/parser/htmlparser/tests/mochitest/parser_datreader.js
@@ -13,7 +13,7 @@
 /**
  * A few utility functions.
  */
-function log(entry) {}
+function log() {}
 
 function startsWith(s, s2) {
   return s.indexOf(s2) == 0;
diff --git a/parser/htmlparser/tests/mochitest/parser_web_testrunner.js b/parser/htmlparser/tests/mochitest/parser_web_testrunner.js
index 5a0cfc64c8..49c09d484a 100644
--- a/parser/htmlparser/tests/mochitest/parser_web_testrunner.js
+++ b/parser/htmlparser/tests/mochitest/parser_web_testrunner.js
@@ -60,7 +60,7 @@ function writeErrorSummary(input, expected, got, isTodo) {
  * event handler returned by makeTestChecker() or the callback returned by
  * makeFragmentTestChecker() until the 'testcases' iterator is spent.
  */
-function makeTestChecker(input, expected, errors) {
+function makeTestChecker(input, expected) {
   return function (e) {
     var domAsString = docToTestOutput(e.target.contentDocument);
     if (html5Exceptions[input]) {
diff --git a/parser/htmlparser/tests/mochitest/test_bug1646140-1.html b/parser/htmlparser/tests/mochitest/test_bug1646140-1.html
index 8592d0d17f..5dfe7cd8e8 100644
--- a/parser/htmlparser/tests/mochitest/test_bug1646140-1.html
+++ b/parser/htmlparser/tests/mochitest/test_bug1646140-1.html
@@ -7,7 +7,7 @@
 SimpleTest.waitForExplicitFinish();
 
 window.svgRanScript = false;
-const o = new MutationObserver(mutations => {
+const o = new MutationObserver(() => {
   o.disconnect();
   setTimeout(() => {
     ok(!svgRanScript, "svg onload must not fire");
diff --git a/parser/htmlparser/tests/mochitest/test_bug1646140-2.html b/parser/htmlparser/tests/mochitest/test_bug1646140-2.html
index 11c370d401..9ea4f305a4 100644
--- a/parser/htmlparser/tests/mochitest/test_bug1646140-2.html
+++ b/parser/htmlparser/tests/mochitest/test_bug1646140-2.html
@@ -10,7 +10,7 @@ document.addEventListener("copy", ev => {
   ev.preventDefault();
   ev.clipboardData.setData('text/html', "<svg><style><svg/onload=\"window.svgRanScript=true\">");
 });
-const o = new MutationObserver(mutations => {
+const o = new MutationObserver(() => {
   o.disconnect();
   setTimeout(() => {
     ok(!svgRanScript, "svg onload must not fire");