@rrweb/record

Minor Changes

• Add a top-level annotation event with record.addAnnotation() and replayer.on('annotation', handler). Annotation data uses type: 'caption' or type: 'timelineMarker'. Import annotationData from @rrweb/types to type annotation data. The player can display these annotations as captions and interactive timeline markers.

Patch Changes

• Fix record-side memory leaks and duplicate mutation emission:

  • Stopping a recording now releases the root document's mutation buffer and observer — previously the document observer was only disconnected, so each start/stop cycle leaked one buffer — and removes the cross-origin iframe message listener.

  • A same-origin iframe is observed once instead of re-observed on every full snapshot (checkoutEveryNth/checkoutEveryNms/manual takeFullSnapshot), so a single iframe mutation is no longer emitted once per checkout; its observers are also released when the iframe is removed or navigates away.

  • The untainted-MutationObserver helper iframe used on WebKit/Safari is reference-counted, so it is torn down only when the last observer stops and will get rebuilt for a later recording.

• Disconnect shadow-DOM observers when their host is removed

  Each observed shadow root kept a live MutationObserver plus its mutation buffer for the rest of the recording session even if its host was removed, a memory leak problem for component-heavy pages. Fix: release shadow observers and buffers as soon as we observe them as removed/detached from dom with tests added for the still-attached host-moved case, and to ensure they get re-observed on reinsertion.

• Release removed shadow trees from the mirror

  Removing a shadow host from DOM was leaving references to shadow descendants, so e.g. repeatedly replacing web components mem-leaked their detached trees. Fix by recursing into shadow roots during removal, including nested hosts and releasing strong references from the mirror.

Patch Changes

• Fix #1920 - normalization of '0px' in style sheets caused problems with the styled-components library, which built style elements text element by text element. Bug introduced

Patch Changes

• Improve performance of untainted dom accessors. Since #1509 we use e.g. dom.parentNode(el) instead of el.parentNode to work around libraries that modify these accessors. Slight improvement to avoid a string allocation each time one of these is called; they are on every hot path.

• Improvements in efficiency of mutation handling at record time; has been identified as a problem numerous times