♻️ [PANA-5123] Assign node ids in preorder when serializing

packages/rum/src/domain/record/index.ts

@@ -1,6 +1,6 @@
 export { record } from './record'
 export type { SerializationMetric, SerializationStats } from './serialization'
 export { createSerializationStats, aggregateSerializationStats } from './serialization'
-export { serializeNodeWithId, serializeDocument } from './serialization'
+export { serializeNode, serializeDocument } from './serialization'
 export { createElementsScrollPositions } from './elementsScrollPositions'
 export type { ShadowRootsController } from './shadowRootsController'

packages/rum/src/domain/record/nodeIds.ts

@@ -4,7 +4,7 @@ export type NodeWithSerializedNode = Node & { __brand: 'NodeWithSerializedNode'
 export type NodeId = number & { __brand: 'NodeId' }
 
 export const enum NodeIdConstants {
-  FIRST_ID = 1,
+  FIRST_ID = 0,
 }
 
 export interface NodeIds {

packages/rum/src/domain/record/serialization/htmlAst.specHelper.ts

@@ -2,7 +2,7 @@ import { NodePrivacyLevel, PRIVACY_ATTR_NAME } from '@datadog/browser-rum-core'
 import { display, objectValues } from '@datadog/browser-core'
 import type { SerializedNodeWithId } from '../../../types'
 import { createSerializationTransactionForTesting } from '../test/serialization.specHelper'
-import { serializeNodeWithId } from './serializeNode'
+import { serializeNode } from './serializeNode'
 
 export const makeHtmlDoc = (htmlContent: string, privacyTag: string) => {
   try {
@@ -30,7 +30,7 @@ export const generateLeanSerializedDoc = (htmlContent: string, privacyTag: strin
   const transaction = createSerializationTransactionForTesting()
   const newDoc = makeHtmlDoc(htmlContent, privacyTag)
   const serializedDoc = removeIdFieldsRecursivelyClone(
-    serializeNodeWithId(newDoc, NodePrivacyLevel.ALLOW, transaction) as unknown as Record<string, unknown>
+    serializeNode(newDoc, NodePrivacyLevel.ALLOW, transaction) as unknown as Record<string, unknown>
   ) as unknown as SerializedNodeWithId
   return serializedDoc
 }

packages/rum/src/domain/record/serialization/index.ts

@@ -1,6 +1,6 @@
 export { getElementInputValue } from './serializationUtils'
 export { serializeDocument } from './serializeDocument'
-export { serializeNodeWithId } from './serializeNode'
+export { serializeNode } from './serializeNode'
 export { serializeAttribute } from './serializeAttribute'
 export { createSerializationStats, updateSerializationStats, aggregateSerializationStats } from './serializationStats'
 export type { SerializationMetric, SerializationStats } from './serializationStats'

packages/rum/src/domain/record/serialization/serializationTransaction.ts

@@ -29,6 +29,12 @@ export interface SerializationTransaction {
    */
   addMetric(metric: keyof SerializationStats, value: number): void
 
+  /**
+   * Assign and return an id to the given node. If the node has previously been assigned
+   * an id, the existing id will be reused.
+   */
+  assignId(node: Node): NodeId
+
   /** The kind of serialization being performed in this transaction. */
   kind: SerializationKind
 
@@ -59,12 +65,19 @@ export function serializeInTransaction(
   const stats = createSerializationStats()
 
   const transaction: SerializationTransaction = {
-    add: (record: BrowserRecord) => {
+    add(record: BrowserRecord): void {
       records.push(record)
     },
-    addMetric: (metric: keyof SerializationStats, value: number) => {
+    addMetric(metric: keyof SerializationStats, value: number): void {
       updateSerializationStats(stats, metric, value)
     },
+    assignId(node: Node): NodeId {
+      const id = scope.nodeIds.assign(node)
+      if (transaction.serializedNodeIds) {
+        transaction.serializedNodeIds.add(id)
+      }
+      return id
+    },
     kind,
     scope,
   }

packages/rum/src/domain/record/serialization/serializeDocument.ts

@@ -1,13 +1,13 @@
 import type { DocumentNode, SerializedNodeWithId } from '../../../types'
-import { serializeNodeWithId } from './serializeNode'
+import { serializeNode } from './serializeNode'
 import type { SerializationTransaction } from './serializationTransaction'
 
 export function serializeDocument(
   document: Document,
   transaction: SerializationTransaction
 ): DocumentNode & SerializedNodeWithId {
   const defaultPrivacyLevel = transaction.scope.configuration.defaultPrivacyLevel
-  const serializedNode = serializeNodeWithId(document, defaultPrivacyLevel, transaction)
+  const serializedNode = serializeNode(document, defaultPrivacyLevel, transaction)
 
   // We are sure that Documents are never ignored, so this function never returns null
   return serializedNode as DocumentNode & SerializedNodeWithId