feat(hydration error): Create a tree-view that highlights dom mutations directly

static/app/components/replays/diff/replayDiffChooser.tsx

@@ -1,6 +1,7 @@
 import styled from '@emotion/styled';
 
 import FeatureBadge from 'sentry/components/badge/featureBadge';
+import {ReplayMutationTree} from 'sentry/components/replays/diff/replayMutationTree';
 import {ReplaySideBySideImageDiff} from 'sentry/components/replays/diff/replaySideBySideImageDiff';
 import {ReplaySliderDiff} from 'sentry/components/replays/diff/replaySliderDiff';
 import {ReplayTextDiff} from 'sentry/components/replays/diff/replayTextDiff';
@@ -22,6 +23,7 @@ export const enum DiffType {
   HTML = 'html',
   SLIDER = 'slider',
   VISUAL = 'visual',
+  MUTATIONS = 'mutations',
 }
 
 export default function ReplayDiffChooser({
@@ -41,6 +43,9 @@ export default function ReplayDiffChooser({
         <TabList>
           <TabList.Item key={DiffType.SLIDER}>{t('Slider Diff')}</TabList.Item>
           <TabList.Item key={DiffType.VISUAL}>{t('Side By Side Diff')}</TabList.Item>
+          <TabList.Item key={DiffType.MUTATIONS}>
+            {t('Mutations')} <FeatureBadge type={'beta'} />
+          </TabList.Item>
           <TabList.Item key={DiffType.HTML}>
             {t('HTML Diff')} <FeatureBadge type={'beta'} />
           </TabList.Item>
@@ -68,6 +73,13 @@ export default function ReplayDiffChooser({
               rightOffsetMs={rightOffsetMs}
             />
           </TabPanels.Item>
+          <TabPanels.Item key={DiffType.MUTATIONS}>
+            <ReplayMutationTree
+              leftOffsetMs={leftOffsetMs}
+              replay={replay}
+              rightOffsetMs={rightOffsetMs}
+            />
+          </TabPanels.Item>
         </StyledTabPanels>
       </TabStateProvider>
     </Grid>

static/app/components/replays/diff/replayMutationTree.tsx

@@ -0,0 +1,53 @@
+import {css} from '@emotion/react';
+import styled from '@emotion/styled';
+
+import StructuredEventData from 'sentry/components/structuredEventData';
+import useExtractDiffMutations from 'sentry/utils/replays/hooks/useExtractDiffMutations';
+import type ReplayReader from 'sentry/utils/replays/replayReader';
+
+interface Props {
+  leftOffsetMs: number;
+  replay: ReplayReader;
+  rightOffsetMs: number;
+}
+
+export function ReplayMutationTree({replay, leftOffsetMs, rightOffsetMs}: Props) {
+  const {data} = useExtractDiffMutations({
+    leftOffsetMs,
+    replay,
+    rightOffsetMs,
+  });
+
+  const timeIndexedMutations = Array.from(data?.values() ?? []).reduce(
+    (mutation, acc) => {
+      for (const timestamp in Object.keys(mutation)) {
+        acc[timestamp] = mutation[timestamp];
+      }
+      return acc;
+    },
+    {}
+  );
+
+  return (
+    <ScrollWrapper>
+      <StructuredEventData
+        key={data?.size}
+        data={timeIndexedMutations}
+        maxDefaultDepth={4}
+        css={css`
+          flex: auto 1 1;
+          & > pre {
+            margin: 0;
+          }
+        `}
+      />
+    </ScrollWrapper>
+  );
+}
+
+const ScrollWrapper = styled('div')`
+  overflow: auto;
+  height: 0;
+  display: flex;
+  flex-grow: 1;
+`;

static/app/utils/replays/hooks/useExtractDiffMutations.tsx

@@ -0,0 +1,222 @@
+import {useQuery, type UseQueryResult} from 'sentry/utils/queryClient';
+import replayerStepper from 'sentry/utils/replays/replayerStepper';
+import type ReplayReader from 'sentry/utils/replays/replayReader';
+import {
+  EventType,
+  IncrementalSource,
+  type RecordingFrame,
+  type ReplayFrame,
+} from 'sentry/utils/replays/types';
+
+type DiffMutation = Record<
+  number,
+  {
+    adds: Record<string, unknown>;
+    attributes: Record<string, unknown>;
+    offset: number;
+    removes: Record<string, unknown>;
+  }
+>;
+
+type Args = {
+  rangeEndTimestampMs: number;
+  rangeStartTimestampMs: number;
+  replay: ReplayReader;
+};
+
+async function extractDiffMutations({
+  rangeEndTimestampMs,
+  rangeStartTimestampMs,
+  replay,
+}: Args): Promise<Map<RecordingFrame, DiffMutation>> {
+  let hasStartedVisiting = false;
+  let hasFinishedVisiting = false;
+  let lastFrame: null | RecordingFrame = null;
+
+  const startTimestampMs = replay.getReplay().started_at.getTime() ?? 0;
+
+  const results = await replayerStepper<RecordingFrame, DiffMutation>({
+    frames: replay.getRRWebFrames(),
+    rrwebEvents: replay.getRRWebFrames(),
+    startTimestampMs,
+    shouldVisitFrame: (frame, _replayer) => {
+      const isWithinRange =
+        rangeStartTimestampMs < frame.timestamp && frame.timestamp <= rangeEndTimestampMs;
+
+      // within the range, so we visit.
+      if (isWithinRange) {
+        hasStartedVisiting = true;
+        return (
+          frame.type === EventType.IncrementalSnapshot &&
+          'source' in frame.data &&
+          frame.data.source === IncrementalSource.Mutation
+        );
+      }
+      // if we started, but didn't record that visiting is finished, then this
+      // is the first frame outside of the range. we'll visit it, so we can
+      // consume the lastFrame, but afterwards no more visits will happen.
+      if (hasStartedVisiting && !hasFinishedVisiting) {
+        hasFinishedVisiting = true;
+        return true;
+      }
+      // we either haven't started, or we already finished, not need to visit.
+      return false;
+    },
+    onVisitFrame: (frame, collection, replayer) => {
+      const mirror = replayer.getMirror();
+
+      if (
+        lastFrame &&
+        lastFrame.type === EventType.IncrementalSnapshot &&
+        'source' in lastFrame.data &&
+        lastFrame.data.source === IncrementalSource.Mutation
+      ) {
+        const adds = {};
+        for (const add of lastFrame.data.adds) {
+          const node = mirror.getNode(add.node.id) as HTMLElement | null;
+          if (!node || !node.outerHTML) {
+            continue;
+          }
+          const selector = getSelectorForElem(node);
+          const rootIsAdded = Object.keys(adds).some(key => selector.startsWith(key));
+          if (rootIsAdded) {
+            continue;
+          }
+
+          adds[selector] = {
+            html: node.outerHTML,
+          };
+        }
+
+        const attributes = {};
+        for (const attr of lastFrame.data.attributes) {
+          const node = mirror.getNode(attr.id) as HTMLElement | null;
+          if (!node || !node.outerHTML) {
+            continue;
+          }
+          attributes[getSelectorForElem(node)] = {
+            tag: node.outerHTML.replace(node.innerHTML, '...'),
+            changed: attr.attributes,
+          };
+        }
+
+        const item = collection.get(lastFrame);
+        if (item) {
+          item[lastFrame.timestamp].adds = adds;
+          item[lastFrame.timestamp].attributes = attributes;
+        }
+      }
+
+      if (
+        frame.type === EventType.IncrementalSnapshot &&
+        'source' in frame.data &&
+        frame.data.source === IncrementalSource.Mutation
+      ) {
+        // fill the cache
+        lastFrame = frame;
+
+        const removes = {};
+        for (const removal of frame.data.removes) {
+          const node = mirror.getNode(removal.id) as HTMLElement | null;
+          if (!node || !node.outerHTML) {
+            continue;
+          }
+          const selector = getSelectorForElem(node);
+          const rootIsRemoved = Object.keys(removes).some(key =>
+            selector.startsWith(key)
+          );
+          if (rootIsRemoved) {
+            continue;
+          }
+
+          removes[selector] = {
+            html: node.outerHTML,
+          };
+        }
+
+        collection.set(frame, {
+          [frame.timestamp]: {
+            adds: {},
+            attributes: {},
+            removes,
+            offset: frame.timestamp - startTimestampMs,
+          },
+        });
+      }
+    },
+  });
+  return results;
+}
+
+function getNameForElem(element: HTMLElement) {
+  if (element.id) {
+    return `#${element.id}`;
+  }
+  const parts = [
+    element.tagName.toLowerCase(),
+    element.className && typeof element.className === 'string'
+      ? `.${element.className.split(' ').filter(Boolean).join('.')}`
+      : '',
+  ];
+  const attrs = [
+    'data-sentry-element',
+    'data-sentry-source-file',
+    'data-test-id',
+    'data-testid',
+  ];
+  for (const attr of attrs) {
+    const value = element.getAttribute(attr);
+    if (value) {
+      parts.push(`[${attr}=${value}]`);
+    }
+  }
+  return parts.join('');
+}
+
+// Copy Selector => `#blk_router > div.tsqd-parent-container > div > div`
+// Copy JS Path => `document.querySelector("#blk_router > div.tsqd-parent-container > div > div")`
+// Copy XPath => `//*[@id="blk_router"]/div[2]/div/div`
+// Copy Full XPath => `/html/body/div[1]/div[2]/div/div`
+function getSelectorForElem(element: HTMLElement): string {
+  const parts: string[] = [];
+  let elem: HTMLElement | null =
+    element.nodeType !== Node.ELEMENT_NODE ? element.parentElement : element;
+
+  while (elem) {
+    parts.unshift(getNameForElem(elem));
+    if (elem.id !== '' || (elem.getAttribute('data-sentry-element') ?? '') !== '') {
+      break;
+    }
+    elem = elem.parentElement;
+  }
+  return parts.join(' > ');
+}
+
+interface Props {
+  leftOffsetMs: number;
+  replay: ReplayReader;
+  rightOffsetMs: number;
+}
+
+export default function useExtractDiffMutations({
+  leftOffsetMs,
+  replay,
+  rightOffsetMs,
+}: Props): UseQueryResult<Map<ReplayFrame, DiffMutation>> {
+  const startTimestampMs = replay.getReplay().started_at.getTime();
+  const rangeStartTimestampMs = startTimestampMs + leftOffsetMs;
+  const rangeEndTimestampMs = startTimestampMs + rightOffsetMs;
+
+  return useQuery({
+    queryKey: [
+      'extractDiffMutations',
+      replay,
+      rangeStartTimestampMs,
+      rangeEndTimestampMs,
+    ],
+    queryFn: () =>
+      extractDiffMutations({replay, rangeStartTimestampMs, rangeEndTimestampMs}),
+    enabled: true,
+    gcTime: 0, // Infinity,
+  });
+}