fix(ui): preserve large context paste behavior

Author: waleedlatif1

apps/sim/app/_shell/paste-admission-guard.test.tsx

@@ -11,15 +11,26 @@ vi.mock('@sim/emcn', () => ({
   useToast: () => ({ toast: { warning } }),
 }))
 
+import { SIM_SELECTION_MIME } from '@/lib/copilot/chat/selection-clipboard'
 import { PasteAdmissionGuard } from '@/app/_shell/paste-admission-guard'
 
 let host: HTMLDivElement
 let root: Root
 
-function dispatchPaste(target: Element, text: string): Event {
-  const event = new Event('paste', { bubbles: true, cancelable: true, composed: true })
+function dispatchPaste(target: Element, text: string, selectionContext?: string): Event {
+  const event = new Event('paste', {
+    bubbles: true,
+    cancelable: true,
+    composed: true,
+  })
   Object.defineProperty(event, 'clipboardData', {
-    value: { getData: (type: string) => (type === 'text/plain' ? text : '') },
+    value: {
+      getData: (type: string) => {
+        if (type === 'text/plain') return text
+        if (type === SIM_SELECTION_MIME) return selectionContext ?? ''
+        return ''
+      },
+    },
   })
   target.dispatchEvent(event)
   return event
@@ -81,4 +92,19 @@ describe('PasteAdmissionGuard', () => {
 
     expect(dispatchPaste(editable, 'a').defaultPrevented).toBe(false)
   })
+
+  it('lets a compact Sim selection reference bypass its large plain-text representation', () => {
+    const input = document.createElement('textarea')
+    input.dataset.pasteMaxBytes = '4'
+    host.appendChild(input)
+    const selectionContext = JSON.stringify({
+      kind: 'table_selection',
+      tableId: 'table-1',
+      tableName: 'Large table',
+      rowIds: ['row-1'],
+      label: 'Large table (1 row)',
+    })
+
+    expect(dispatchPaste(input, '12345', selectionContext).defaultPrevented).toBe(false)
+  })
 })

apps/sim/app/_shell/paste-admission-guard.tsx

@@ -3,6 +3,7 @@
 import { useEffect, useRef } from 'react'
 import { useToast } from '@sim/emcn'
 import { assessTextPaste, formatPasteLimit, PASTE_LIMITS } from '@sim/utils/paste'
+import { readSelectionContextFromClipboard } from '@/lib/copilot/chat/selection-clipboard'
 
 const EDITABLE_TARGET_SELECTOR =
   'input:not([type="file"]):not([type="checkbox"]):not([type="radio"]):not([type="button"]):not([type="submit"]):not([type="hidden"]), textarea, [contenteditable]:not([contenteditable="false"]), .monaco-editor, .xterm'
@@ -32,6 +33,8 @@ export function PasteAdmissionGuard() {
         return
       }
 
+      if (readSelectionContextFromClipboard(event.clipboardData)) return
+
       const text = event.clipboardData?.getData('text/plain') ?? ''
       if (!text) return
 

apps/sim/app/workspace/[workspaceId]/home/components/user-input/components/prompt-editor/use-prompt-editor.test.tsx

@@ -11,6 +11,7 @@ vi.mock('@/blocks/integration-matcher', () => ({
   getIntegrationMatcher: () => ({ regex: null, byName: new Map() }),
 }))
 
+import { SIM_SELECTION_MIME } from '@/lib/copilot/chat/selection-clipboard'
 import type { PlusMenuHandle } from '@/app/workspace/[workspaceId]/home/components/user-input/components/constants'
 import {
   type UsePromptEditorProps,
@@ -278,6 +279,42 @@ describe('usePromptEditor context insertion', () => {
     unmount()
   })
 
+  it('pastes a large table selection as a compact context chip', () => {
+    vi.spyOn(window, 'requestAnimationFrame').mockImplementation((callback) => {
+      callback(0)
+      return 1
+    })
+    const context = {
+      kind: 'table_selection',
+      tableId: 'table-1',
+      tableName: 'Large table',
+      rowIds: ['row-1'],
+      label: 'Large table (1 row)',
+    } satisfies ChatContext
+    const { result, textarea, unmount } = renderPromptEditor({ workspaceId: 'ws-1' })
+    const preventDefault = vi.fn()
+
+    act(() => {
+      result().handlePaste({
+        currentTarget: textarea,
+        clipboardData: {
+          getData: (type: string) => {
+            if (type === 'text/plain') return 'x'.repeat(1_000_001)
+            if (type === SIM_SELECTION_MIME) return JSON.stringify(context)
+            return ''
+          },
+        },
+        preventDefault,
+      } as unknown as React.ClipboardEvent<HTMLTextAreaElement>)
+    })
+
+    expect(preventDefault).toHaveBeenCalledOnce()
+    expect(result().value).toBe('@Large table (1 row) ')
+    expect(result().contexts).toEqual([context])
+
+    unmount()
+  })
+
   it('suffixes duplicate visible labels so two browser selections coexist', () => {
     vi.spyOn(window, 'requestAnimationFrame').mockImplementation((callback) => {
       callback(0)
@@ -295,7 +332,9 @@ describe('usePromptEditor context insertion', () => {
       label: 'Browser · Another page title',
       selection: { text: 'second selection', url: 'https://example.com' },
     } satisfies ChatContext
-    const { result, textarea, unmount } = renderPromptEditor({ workspaceId: 'ws-1' })
+    const { result, textarea, unmount } = renderPromptEditor({
+      workspaceId: 'ws-1',
+    })
 
     act(() => {
       result().insertContext(first)

apps/sim/app/workspace/[workspaceId]/home/components/user-input/components/prompt-editor/use-prompt-editor.ts

@@ -991,26 +991,6 @@ export function usePromptEditor({
   const handlePaste = useCallback((e: React.ClipboardEvent<HTMLTextAreaElement>) => {
     const textarea = e.currentTarget
     const pastedPlainText = e.clipboardData?.getData('text/plain') ?? ''
-    if (pastedPlainText) {
-      const admission = assessTextPaste({
-        pastedText: pastedPlainText,
-        maxPastedBytes: PASTE_LIMITS.CHAT_BYTES,
-        maxPastedCharacters: PASTE_LIMITS.CHAT_CHARACTERS,
-        currentText: textarea.value,
-        selectionStart: textarea.selectionStart,
-        selectionEnd: textarea.selectionEnd,
-        maxResultBytes: PASTE_LIMITS.CHAT_BYTES,
-        maxResultCharacters: PASTE_LIMITS.CHAT_CHARACTERS,
-      })
-      if (!admission.accepted) {
-        e.preventDefault()
-        toast.warning('Paste is too large for a message', {
-          description: `Messages support up to ${PASTE_LIMITS.CHAT_CHARACTERS.toLocaleString()} characters. Attach the content as a file to send more without slowing the editor.`,
-        })
-        return
-      }
-    }
-
     // A selection copied from a file/table (Cmd+C) carries its context on a
     // custom clipboard type — paste it as a reference chip instead of plain text.
     // Registers via `addContext` (not the notified path) so paste never opens a
@@ -1039,6 +1019,26 @@ export function usePromptEditor({
       return
     }
 
+    if (pastedPlainText) {
+      const admission = assessTextPaste({
+        pastedText: pastedPlainText,
+        maxPastedBytes: PASTE_LIMITS.CHAT_BYTES,
+        maxPastedCharacters: PASTE_LIMITS.CHAT_CHARACTERS,
+        currentText: textarea.value,
+        selectionStart: textarea.selectionStart,
+        selectionEnd: textarea.selectionEnd,
+        maxResultBytes: PASTE_LIMITS.CHAT_BYTES,
+        maxResultCharacters: PASTE_LIMITS.CHAT_CHARACTERS,
+      })
+      if (!admission.accepted) {
+        e.preventDefault()
+        toast.warning('Paste is too large for a message', {
+          description: `Messages support up to ${PASTE_LIMITS.CHAT_CHARACTERS.toLocaleString()} characters. Attach the content as a file to send more without slowing the editor.`,
+        })
+        return
+      }
+    }
+
     // Portable chip links (`[label](sim:kind/id)`) re-create their chip on
     // paste-back. Rewrite each link span to its `@label ` token (the trailing
     // space is REQUIRED so useContextManagement's sync effect doesn't purge the

apps/sim/app/workspace/[workspaceId]/home/components/user-input/user-input.tsx

@@ -536,6 +536,11 @@ const UserInputImpl = forwardRef<UserInputHandle, UserInputProps>(function UserI
     )
     currentEditor.clear()
     sttPrefixRef.current = ''
+    if (draftSaveTimerRef.current !== null) {
+      window.clearTimeout(draftSaveTimerRef.current)
+      draftSaveTimerRef.current = null
+    }
+    pendingDraftRef.current = null
     if (draftScopeKeyRef.current) {
       useMothershipDraftsStore.getState().clearDraft(draftScopeKeyRef.current)
     }