fix(chat): keep messages chronological across ID rollover

packages/ui/src/sync/materialization.ts

@@ -1,8 +1,8 @@
 import type { Message, Part } from "@opencode-ai/sdk/v2/client"
 import { mergeMessages } from "./optimistic"
 import type { SessionMaterializationReason } from "./event-reducer"
+import { sortMessagesChronologically } from "./message-ordering"
 
-const cmp = (a: string, b: string) => (a < b ? -1 : a > b ? 1 : 0)
 const STREAMING_PART_FIELDS = ["text", "output"] as const
 const ACTIVE_TOOL_STATUSES = new Set(["pending", "running"])
 const FINAL_TOOL_STATUSES = new Set(["completed", "error", "aborted", "failed", "timeout", "cancelled"])
@@ -93,10 +93,9 @@ export function getStaleRunningToolMessageID(
   return undefined
 }
 
-function sortParts(parts: Part[], skipPartTypes: ReadonlySet<string>) {
+function filterMaterializedParts(parts: Part[], skipPartTypes: ReadonlySet<string>): Part[] {
   return parts
     .filter((part) => !!part?.id && !skipPartTypes.has(part.type))
-    .sort((a, b) => cmp(a.id, b.id))
 }
 
 function haveEquivalentPartSnapshots(left: Part[] | undefined, right: Part[]): boolean {
@@ -252,7 +251,7 @@ function mergeMaterializedParts(
   )
   if (missingLiveParts.length === 0) return mergedParts
 
-  return [...mergedParts, ...missingLiveParts].sort((a, b) => cmp(a.id, b.id))
+  return [...mergedParts, ...missingLiveParts]
 }
 
 export function materializeSessionSnapshots(
@@ -262,10 +261,13 @@ export function materializeSessionSnapshots(
   options: MaterializeSessionSnapshotsOptions = {},
 ): MaterializeSessionSnapshotsResult {
   const skipPartTypes = options.skipPartTypes ?? new Set<string>()
-  const snapshots = records
-    .filter((record) => !!record?.info?.id)
-    .sort((left, right) => cmp(left.info.id, right.info.id))
-  const nextMessages = snapshots.map((record) => record.info)
+  const recordsByMessageID = new Map(
+    records
+      .filter((record) => !!record?.info?.id)
+      .map((record) => [record.info.id, record] as const),
+  )
+  const nextMessages = sortMessagesChronologically([...recordsByMessageID.values()].map((record) => record.info))
+  const snapshots = nextMessages.map((message) => recordsByMessageID.get(message.id)!)
   const existingMessages = state.message[sessionID]
   const currentMessages = existingMessages ?? []
   const messages = mergeMessages(currentMessages, nextMessages)
@@ -283,7 +285,7 @@ export function materializeSessionSnapshots(
     const existing = nextPartState[messageID]
     const nextParts = mergeMaterializedParts(
       existing,
-      sortParts(record.parts ?? [], skipPartTypes),
+      filterMaterializedParts(record.parts ?? [], skipPartTypes),
       skipPartTypes,
       isAssistant,
     )