chore: import upstream snapshot with attribution

apps/sim/lib/copilot/request/sse-utils.ts

@@ -0,0 +1,75 @@
+import { STREAM_BUFFER_MAX_DEDUP_ENTRIES } from '@/lib/copilot/constants'
+import {
+  isToolCallStreamEvent,
+  isToolResultStreamEvent,
+  type ToolCallStreamEvent,
+  type ToolResultStreamEvent,
+} from '@/lib/copilot/request/session'
+import { TOOL_CALL_STATUS } from '@/lib/copilot/request/session/event'
+import type { StreamEvent } from '@/lib/copilot/request/types'
+
+/** Safely cast event.data to a record for property access. */
+export const asRecord = (data: unknown): Record<string, unknown> =>
+  (data && typeof data === 'object' && !Array.isArray(data) ? data : {}) as Record<string, unknown>
+
+/**
+ * In-memory tool event dedupe with bounded size.
+ *
+ * NOTE: Process-local only. In a multi-instance setup (e.g., ECS),
+ * each task maintains its own dedupe cache.
+ */
+const seenToolCalls = new Set<string>()
+const seenToolResults = new Set<string>()
+
+function addToSet(set: Set<string>, id: string): void {
+  if (set.size >= STREAM_BUFFER_MAX_DEDUP_ENTRIES) {
+    const first = set.values().next().value
+    if (first) set.delete(first)
+  }
+  set.add(id)
+}
+
+function getToolCallIdFromCallEvent(event: ToolCallStreamEvent): string {
+  return event.payload.toolCallId
+}
+
+function getToolCallIdFromResultEvent(event: ToolResultStreamEvent): string {
+  return event.payload.toolCallId
+}
+
+function markToolCallSeen(toolCallId: string): void {
+  addToSet(seenToolCalls, toolCallId)
+}
+
+function wasToolCallSeen(toolCallId: string): boolean {
+  return seenToolCalls.has(toolCallId)
+}
+
+export function markToolResultSeen(toolCallId: string): void {
+  addToSet(seenToolResults, toolCallId)
+}
+
+export function wasToolResultSeen(toolCallId: string): boolean {
+  return seenToolResults.has(toolCallId)
+}
+
+export function shouldSkipToolCallEvent(event: StreamEvent): boolean {
+  if (!isToolCallStreamEvent(event)) return false
+  if (isPathlessVfsGeneratingEvent(event)) return true
+  if (event.payload.status === TOOL_CALL_STATUS.generating) return false
+  const toolCallId = getToolCallIdFromCallEvent(event)
+  if (event.payload.partial === true) return false
+  if (wasToolResultSeen(toolCallId) || wasToolCallSeen(toolCallId)) return true
+  markToolCallSeen(toolCallId)
+  return false
+}
+
+function isPathlessVfsGeneratingEvent(event: ToolCallStreamEvent): boolean {
+  if (event.payload.status !== TOOL_CALL_STATUS.generating) return false
+  if (event.payload.toolName !== 'read' && event.payload.toolName !== 'glob') return false
+  return event.payload.arguments === undefined
+}
+
+export function shouldSkipToolResultEvent(event: StreamEvent): boolean {
+  return isToolResultStreamEvent(event) && wasToolResultSeen(getToolCallIdFromResultEvent(event))
+}