--- a/devtools/client/framework/test/browser_browser_toolbox_debugger.js
+++ b/devtools/client/framework/test/browser_browser_toolbox_debugger.js
@@ -110,17 +110,17 @@ add_task(async function runTest() {
       return new Promise(resolve => {
         // TODO: fixme.
         // eslint-disable-next-line mozilla/no-arbitrary-setTimeout
         setTimeout(function() {
           waitUntil(predicate, interval).then(() => resolve(true));
         }, interval);
       });
     }
-  }).toSource().replace(/^\(function \(\) \{|\}\)$/g, "");
+  }).toSource().replace(/^\(function\(\) \{|\}\)$/g, "");
   // Stringify testHead's function and remove `(function {` prefix and `})` suffix
   // to ensure inner symbols gets exposed to next pieces of code
 
   // Then inject new debugger head file
   let { content } = await fetch(debuggerHeadURL);
   let debuggerHead = content;
   // We remove its import of shared-head, which isn't available in browser toolbox process
   // And isn't needed thanks to testHead's symbols

--- a/devtools/client/framework/test/browser_toolbox_window_shortcuts.js
+++ b/devtools/client/framework/test/browser_toolbox_window_shortcuts.js
@@ -19,20 +19,22 @@ function test() {
       if (!shortcut) {
         continue;
       }
       toolIDs.push(id);
       toolShortcuts.push(shortcut);
 
       // Enable disabled tools
       let pref = definition.visibilityswitch;
-      let prefValue = Services.prefs.getBoolPref(pref, false);
-      if (!prefValue) {
-        modifiedPrefs.push(pref);
-        Services.prefs.setBoolPref(pref, true);
+      if (pref) {
+        let prefValue = Services.prefs.getBoolPref(pref, false);
+        if (!prefValue) {
+          modifiedPrefs.push(pref);
+          Services.prefs.setBoolPref(pref, true);
+        }
       }
     }
     let target = TargetFactory.forTab(gBrowser.selectedTab);
     idIndex = 0;
     gDevTools.showToolbox(target, toolIDs[0], Toolbox.HostType.WINDOW)
              .then(testShortcuts);
   });
 }

--- a/devtools/client/scratchpad/test/browser_scratchpad_eval_func.js
+++ b/devtools/client/scratchpad/test/browser_scratchpad_eval_func.js
@@ -17,22 +17,20 @@ function reportErrorAndQuit(error) {
   DevToolsUtils.reportException("browser_scratchpad_eval_func.js", error);
   ok(false);
   finish();
 }
 
 function runTests(sw) {
   const sp = sw.Scratchpad;
 
-  let foo = "" + function main() {
-    console.log(1);
-  };
-  let bar = "var bar = " + (() => {
-    console.log(2);
-  });
+  /* eslint-disable brace-style */
+  let foo = "" + function main() { console.log(1); };
+  let bar = "var bar = " + (() => { console.log(2); });
+  /* eslint-enable brace-style */
 
   const fullText =
     foo + "\n" +
     "\n" +
     bar + "\n";
 
   sp.setText(fullText);