Developer Tools help developers write and debug websites on Firefox. This newsletter gives an overview of the work we’ve done as part of the Firefox 134 release cycle.

Firefox being an open source project, we are grateful to get contributions from people outside of Mozilla:

• AAR made the Inspector Font editor round some values (#1465026)
• Abhijeet Chawla migrated some of our React code away from deprecated method (#1810437, #1810462)

Want to help? DevTools are written in HTML, CSS and JS so any web developer can contribute! Read how to setup the work environment and check the list of mentored issues

Highlights

• The “Pause on caught exception” setting wasn’t persisted after DevTools was reloaded, this is now fixed (#1930687)
• We made the information in the “Why Paused panel” (i.e. the section in the Debugger that indicates that the page is paused and why) properly accessible to screenreaders (e.g. NVDA) by making it a live region (#1843320, #1927108)
• Still around accessibility, we improved the inspector markup view breadcrumb component, properly setting the aria-pressed attribute on the selected item
• We fixed an annoying issue in the Inspector where clicking an element would impact horizontal scroll (#1926983)
• Finally, we removed unhelpful (fallback document) URL element in WebExtensions toolboxes (#1928336)

That’s it for this month, thank you for reading this and using our tools, see you in a few weeks for a new round of updates 🙂

---

Full list of fixed bugs in DevTools for the Firefox 134 release:

• AAR Font editor: values should be rounded (#1465026)
• Abhijeet Chawla[:ff2400t] Stop using UNSAFE_componentWillMount in devtools/client/shared/components/Frame.js (#1810437)
• Abhijeet Chawla[:ff2400t] Stop using UNSAFE_componentWillReceiveProps in devtools/client/inspector/animation/components/keyframes-graph/ColorPath.js (#1810462)
• Sandor Molnar[:smolnar] Intermittent devtools/client/debugger/test/mochitest/browser_dbg-editor-scroll.js | single tracking bug (#1833502)
• Joel Maher ( :jmaher ) (UTC -8) Intermittent devtools/client/webconsole/test/browser/browser_webconsole_location_logpoint_debugger_link.js | single tracking bug (#1844156)
• Tooru Fujisawa [:arai] Do not use -no-remote in Browser Toolbox startup (#1926803)
• Jeff Muizelaar [:jrmuizel] Add profiler markers for debugger log points (#1928514)
• Nobody; OK to take it and work on it Intermittent [TV] devtools/client/debugger/test/mochitest/browser_dbg-javascript-tracer-sidebar-values-search.js | Uncaught exception in test bound – at chrome://mochitests/content/browser/devtools/client/shared/test/shared-head.js:1106 (#1928534)
• Jon Coppeard (:jonco) Intermittent Assertion failure: element, at /builds/worker/checkouts/gecko/js/src/ds/SinglyLinkedList.h:74 (#1929431)
• Alexandre Poirot [:ochameau] Instantiate WebExtension top level target from the server side — support server side target switching for webext (#1754452)
• Alexandre Poirot [:ochameau] Almost perma devtools/client/aboutdebugging/test/browser/browser_aboutdebugging_addons_popup_picker.js | single tracking bug (#1854033)
• Alexandre Poirot [:ochameau] Allow search for traces by function call argument values (#1921020)
• Alexandre Poirot [:ochameau] Fire onTargetSelected on startup to pick the visible target (#1924710)
• Alexandre Poirot [:ochameau] Avoid showing the target’s URL for WebExtensions (#1928336)
• Alexandre Poirot [:ochameau] Remove now-unused codepath related to debugging WebExtension via WebExtensionDescriptor.getTarget (#1928510)
• Alexandre Poirot [:ochameau] Make the DevTools tracer button use the native profiler pipeline (#1929003)
• Alexandre Poirot [:ochameau] Record DOM Mutations when tracing to the profiler (#1929004)
• Alexandre Poirot [:ochameau] Store console API calls in recorded tracing profiles (#1929007)
• Alexandre Poirot [:ochameau] Loads reps modules with absolute URLs (instead of absolute require path) (#1929388)
• Alexandre Poirot [:ochameau] Import object inspector modules directly instead of going through Reps’s index module (#1929390)
• Alexandre Poirot [:ochameau] Perma Windows devtools/client/debugger/test/mochitest/browser_dbg-javascript-tracer-sidebar.js | The key event adds two elements in the tree. The DOM Event and its top frame – Got 7, expected 8 (#1929934)
• Alexandre Poirot [:ochameau] Pause on caught exception settings isn’t applied on DevTools startup (#1930687)
• Alexandre Poirot [:ochameau] Restore `threadGrip` method of paused object actors (#1935473)
• Hubert Boma Manilla (:bomsy) Show 103 Early Hints Information in the Netmonitor (#1811455)
• Hubert Boma Manilla (:bomsy) Semantically indicate current paused line when stepping (#1843320)
• Nicolas Chevobbe [:nchevobbe] Remove additional accessibility panel “beta” code (#1852762)
• Hubert Boma Manilla (:bomsy) Stop using the parser worker for determining specific frameworks (#1873432)
• Julian Descottes [:jdescottes] Intermittent devtools/client/inspector/rules/test/browser_rules_pseudo-element_01.js | single tracking bug (#1911521)
• Nicolas Chevobbe [:nchevobbe] Active tab in toolbox toolbar only differs from inactive tab by its icon color in High Contrast Mode (#1916335)
• Nicolas Chevobbe [:nchevobbe] “Jump to function” icon keep its original color in High Contrast Mode (#1916346)
• Nicolas Chevobbe [:nchevobbe] Pause/Resume button keep its original active color in High Contrast Mode (#1916358)
• Nicolas Chevobbe [:nchevobbe] Active tab is difficult to spot in High Contrast Mode (#1916372)
• Nicolas Chevobbe [:nchevobbe] Performance analysis charts legend don’t match chart colors in High Contrast Mode (#1916391)
• Nicolas Chevobbe [:nchevobbe] event/scroll/flex/grid badges have low contrast border in High Contrast Mode (#1916608)
• Nicolas Chevobbe [:nchevobbe] scroll badges don’t have distinct active style in High Contrast Mode (#1916617)
• Nicolas Chevobbe [:nchevobbe] Selected item in breadcrumb panel isn’t visible in High Contrast Mode (#1916650)
• Nicolas Chevobbe [:nchevobbe] Breadcrumb separator icon color does not adapt to High Contrast Mode (#1916656)
• Nicolas Chevobbe [:nchevobbe] Reordering element with drag and drop in markup view doesn’t show feedback in High Contrast Mode (#1916660)
• Nicolas Chevobbe [:nchevobbe] Rules view accordion text isn’t legible on hover in High Contrast Mode (#1916669)
• Nicolas Chevobbe [:nchevobbe] Bezier tooltip curve editor does not adapt to High Contrast Mode (#1916682)
• Nicolas Chevobbe [:nchevobbe] Non visible element (e.g. display:none) nodes are not different from other nodes in High Contrast Mode (#1916688)
• Nicolas Chevobbe [:nchevobbe] Linear editor does not adapt to High Contrast Mode (#1916693)
• Nicolas Chevobbe [:nchevobbe] Rules view search result highlight are not visible in High Contrast Mode (#1916698)
• Nicolas Chevobbe [:nchevobbe] Active Rules view toolbar button style is almost the same as non-active buttons in High Contrast Mode (#1916700)
• Nicolas Chevobbe [:nchevobbe] Computed panel detail panel border may be too subtle in High Contrast Mode (#1916721)
• Nicolas Chevobbe [:nchevobbe] Computed panel location don’t look like a link in High Contrast Mode (#1916722)
• Nicolas Chevobbe [:nchevobbe] Selected node when tree isn’t focused doesn’t appear to be selected in High Contrast Mode (#1917782)
• Nicolas Chevobbe [:nchevobbe] Markup view flash on mutation doesn’t look good in High Contrast Mode (#1920711)
• Nicolas Chevobbe [:nchevobbe] Use aria-pressed for selected breadcrumb item (#1921758)
• Nicolas Chevobbe [:nchevobbe] Perma [tier 2] devtools/client/debugger/test/mochitest/browser_dbg-blackbox.js | We expect at least one assertion to fail because this test file is marked as fail-if in the manifest. – (#1925030)
• Nicolas Chevobbe [:nchevobbe] Umatched selectors, overridden/inactive declarations don’t have distinct color in High Contrast Mode (#1926794)
• Nicolas Chevobbe [:nchevobbe] Rules view dirty/new indicator is always displayed in high Contrast Mode (#1926851)
• Nicolas Chevobbe [:nchevobbe] Rules view property name/value hover dashed underline is always visible in high Contrast Mode (#1926852)
• Nicolas Chevobbe [:nchevobbe] “Start Performance analysis ” button does not adapt to High Contrast Mode (#1926878)
• Nicolas Chevobbe [:nchevobbe] Stop changing the horizontal scroll with Mouse Down on Inspector (#1926983)
• Nicolas Chevobbe [:nchevobbe] Splitters look weird in High Contrast Mode (#1927063)
• Hubert Boma Manilla (:bomsy) The information in the Why Paused panel is not read properly with NVDA on windows (#1927108)
• Hubert Boma Manilla (:bomsy) Use light-dark() in debugger variables.css (#1927133)
• Nicolas Chevobbe [:nchevobbe] Perma [tier 2] devtools/client/inspector/markup/test/browser_markup_tag_edit_long-classname.js | Node is not accessible via accessibility API: id: ruleview-container-focusable, tagName: div, className: – (#1928003)
• Nicolas Chevobbe [:nchevobbe] Disabled buttons should not be translucid in High Contrast Mode (#1928108)
• Nicolas Chevobbe [:nchevobbe] Intermittent devtools/client/inspector/test/browser_inspector_fission_frame_navigation.js | single tracking bug (#1928134)
• Nicolas Chevobbe [:nchevobbe] Accessibility components/Button.js isn’t used anywhere (#1929006)
• Nicolas Chevobbe [:nchevobbe] Markup view expand button (the one between opening/closing tag, not twisty) should have a ButtonText color in High Contrast Mode (#1929200)
• Nicolas Chevobbe [:nchevobbe] Selected tree node twisty icon are white in High Contrast Mode (they should be SelectedItemText) (#1929508)
• Nicolas Chevobbe [:nchevobbe] Don’t use opacity to style disabled menuitem (#1929594)
• Nicolas Chevobbe [:nchevobbe] Disabled command buttons should’t change opacity in High Contrast Mode (#1930099)
• Nicolas Chevobbe [:nchevobbe] Remove color transition on buttons (#1930185)
• Nicolas Chevobbe [:nchevobbe] Callstack panel selected frame don’t have the appropriate color in High Contrast Mode (#1930956)
• Nicolas Chevobbe [:nchevobbe] Waterfall get high contrast colors even if toolbox theme is not Auto (#1931499)
• Nicolas Chevobbe [:nchevobbe] Split console top border does not look great in High Contrast Mode (#1931502)
• Nicolas Chevobbe [:nchevobbe] Toolbox top|side border does not adapt to High Contrast Mode (#1931507)
• Julian Descottes [:jdescottes] [DevTools Release Tasks – Cycle 134] Update MDN compat data (#1931530)
• Julian Descottes [:jdescottes] [backward] Webextension remote debugging broken between 134 and 133 (#1932882)
• Hubert Boma Manilla (:bomsy) Remove the Codemirror 6 preference in the debugger (#1935101)