Omkar Kesarkhane 2c17c07a11 fix(rum): restore RUM-traces correlation for zero-stripped trace ids (#13959) ...

## Problem

RUM-to-traces correlation stopped working after the browser SDK 0.4.x
line. The SDK's identifiers became plain `BigInt`, so the unchanged
`toString(16)` serialization silently started dropping leading zeros.
Trace ids are UUIDv7-shaped (48-bit ms timestamp in the top bits), so
the leading hex nibble is always zero today — effectively every RUM
event stored a 31-char `_oo_trace_id`/`_o2_trace_id` while the traces
stream stores the padded 32-char `trace_id` (the `traceparent` header
was padded correctly, so backend traces have the full id). Exact-match
correlation could never hit, in either direction.

Verified against live data: for sampled traced requests, `'0' +
stored_id` found the backend trace every time; the stored id never did.

## Fix (frontend compatibility layer)

Works for the already-ingested short ids **and** for correct ids from
the fixed SDK:

- `utils/rum/fields.ts`: `normalizeTraceId` (pads to canonical 32-char
hex), `traceIdLookupVariants` (padded + legacy zero-stripped forms),
`rumFieldEqualsAnySql` (matches both namespace spellings x both id
forms), and a shared `RUM_CORRELATION_TRACES_STREAM` constant replacing
four scattered "default" literals.
- `useRumSpanBuilder`: trace→RUM lookup queries both id forms; canonical
id stamped on generated RUM spans.
- `useTraceCorrelation`: backend-span query now targets the real
`default` traces stream (was a nonexistent `_traces` stream) as
`page_type: "traces"` (was `"logs"`), with the padded id.
- `EventDetailDrawerContent`: trace navigation pads the id before
building the route.
- `PlayerTracesTab`: the session Traces tab canonicalizes ids before the
traces-stream metadata join (rows were silently dropped).
- `ErrorViewer`: error correlation card receives the padded id;
implausible (non-hex) ids hide the card instead of showing a misleading
empty state.
- `package.json`: browser SDK bumped to 0.4.2-beta.3, which serializes
trace/span ids as fixed-width canonical hex at the source (resolved
`browser-rum-core` verified at 0.4.2-beta.3).

## Testing

- New unit coverage: `fields.spec.ts` (16 tests) plus regression tests
in each touched spec (legacy 31-char id fixtures asserting padded
32-char behavior); full RUM/traces suites green (53 files, 1971 passed).
- Live-verified against real data: a trace from the broken window
renders the full RUM hierarchy (Session→View→Action→Resource + backend
spans) where the old code showed backend spans only; pre-regression
sessions still correlate (no behavior change for correct ids).
- `npm run lint` and `npm run type-check` clean.

2026-08-26 04:24:16 +00:00

..

__mocks__

build: FE code format check for improved maintainability (#13351)

2026-07-24 07:11:39 +00:00

unit

fix(rum): restore RUM-traces correlation for zero-stripped trace ids (#13959)

2026-08-26 04:24:16 +00:00