fix(ui): close paste admission edge cases

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

@@ -17,7 +17,11 @@ import { PasteAdmissionGuard } from '@/app/_shell/paste-admission-guard'
 let host: HTMLDivElement
 let root: Root
 
-function dispatchPaste(target: Element, text: string, selectionContext?: string): Event {
+function dispatchPaste(
+  target: Element,
+  text: string,
+  options: { selectionContext?: string; html?: string; imageFile?: boolean } = {}
+): Event {
   const event = new Event('paste', {
     bubbles: true,
     cancelable: true,
@@ -27,9 +31,12 @@ function dispatchPaste(target: Element, text: string, selectionContext?: string)
     value: {
       getData: (type: string) => {
         if (type === 'text/plain') return text
-        if (type === SIM_SELECTION_MIME) return selectionContext ?? ''
+        if (type === SIM_SELECTION_MIME) return options.selectionContext ?? ''
+        if (type === 'text/html') return options.html ?? ''
         return ''
       },
+      files: options.imageFile ? [new File(['image'], 'pasted.png', { type: 'image/png' })] : [],
+      items: options.imageFile ? [{ kind: 'file', type: 'image/png' }] : [],
     },
   })
   target.dispatchEvent(event)
@@ -93,7 +100,36 @@ describe('PasteAdmissionGuard', () => {
     expect(dispatchPaste(editable, 'a').defaultPrevented).toBe(false)
   })
 
-  it('lets a compact Sim selection reference bypass its large plain-text representation', () => {
+  it('defers text admission to an editor that projects its exact paste result', () => {
+    const editor = document.createElement('div')
+    editor.setAttribute('contenteditable', 'true')
+    editor.dataset.pasteMaxBytes = '4'
+    editor.dataset.pasteProjectsTextResult = 'true'
+    host.appendChild(editor)
+
+    const targetHandler = vi.fn()
+    editor.addEventListener('paste', targetHandler)
+    expect(dispatchPaste(editor, '12345').defaultPrevented).toBe(false)
+    expect(targetHandler).toHaveBeenCalledOnce()
+  })
+
+  it('lets a prompt consume a compact Sim selection reference before its large plain text', () => {
+    const input = document.createElement('textarea')
+    input.dataset.pasteMaxBytes = '4'
+    input.dataset.pasteSelectionContext = 'reference'
+    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)
+  })
+
+  it('still bounds a Sim selection plain-text representation outside the prompt', () => {
     const input = document.createElement('textarea')
     input.dataset.pasteMaxBytes = '4'
     host.appendChild(input)
@@ -105,6 +141,37 @@ describe('PasteAdmissionGuard', () => {
       label: 'Large table (1 row)',
     })
 
-    expect(dispatchPaste(input, '12345', selectionContext).defaultPrevented).toBe(false)
+    expect(dispatchPaste(input, '12345', { selectionContext }).defaultPrevented).toBe(true)
+  })
+
+  it('bounds rich HTML separately from its smaller plain-text representation', () => {
+    const editable = document.createElement('div')
+    editable.setAttribute('contenteditable', 'true')
+    editable.dataset.pasteMaxBytes = '100'
+    editable.dataset.pasteMaxHtmlBytes = '10'
+    host.appendChild(editable)
+
+    expect(dispatchPaste(editable, 'abc', { html: '<strong>abc</strong>' }).defaultPrevented).toBe(
+      true
+    )
+  })
+
+  it('lets an opted-in rich editor handle clipboard image files before text admission', () => {
+    const editable = document.createElement('div')
+    editable.setAttribute('contenteditable', 'true')
+    editable.dataset.pasteMaxBytes = '4'
+    editable.dataset.pasteMaxHtmlBytes = '4'
+    editable.dataset.pasteHandlesImages = 'true'
+    host.appendChild(editable)
+
+    const targetHandler = vi.fn()
+    editable.addEventListener('paste', targetHandler)
+    const event = dispatchPaste(editable, '12345', {
+      html: '<img src="data:image/png;base64,large">',
+      imageFile: true,
+    })
+
+    expect(event.defaultPrevented).toBe(false)
+    expect(targetHandler).toHaveBeenCalledOnce()
   })
 })

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

@@ -15,11 +15,20 @@ function finitePositiveAttribute(element: Element | null, name: string): number
   return Number.isFinite(value) && value > 0 ? value : undefined
 }
 
+function clipboardHasImageFile(data: DataTransfer | null): boolean {
+  if (!data) return false
+  if (Array.from(data.files).some((file) => file.type.startsWith('image/'))) return true
+  return Array.from(data.items).some(
+    (item) => item.kind === 'file' && item.type.startsWith('image/')
+  )
+}
+
 /**
  * Last-resort admission for every editable workspace surface. Specialized editors publish their
  * downstream ceiling on an ancestor with `data-paste-max-bytes`; controls without one inherit a
  * crash-only fallback. This layer bounds only the clipboard payload, so a small paste into an already
  * large field keeps native behavior. Editors with a real result-size contract enforce it themselves.
+ * Targets that explicitly handle clipboard images may claim those file events before the text guards.
  * The capture listener runs before React, ProseMirror, Monaco, and xterm parse the clipboard value.
  */
 export function PasteAdmissionGuard() {
@@ -33,31 +42,53 @@ export function PasteAdmissionGuard() {
         return
       }
 
-      if (readSelectionContextFromClipboard(event.clipboardData)) return
+      const acceptsSelectionContext = event.target.closest('[data-paste-selection-context]')
+      if (acceptsSelectionContext && readSelectionContextFromClipboard(event.clipboardData)) return
 
-      const text = event.clipboardData?.getData('text/plain') ?? ''
-      if (!text) return
+      const handlesImageFiles = event.target.closest('[data-paste-handles-images="true"]')
+      if (handlesImageFiles && clipboardHasImageFile(event.clipboardData)) return
 
+      const text = event.clipboardData?.getData('text/plain') ?? ''
+      const projectsTextResult = event.target.closest('[data-paste-projects-text-result="true"]')
       const policyElement = event.target.closest('[data-paste-max-bytes]')
       const maxPastedBytes =
         finitePositiveAttribute(policyElement, 'data-paste-max-bytes') ?? PASTE_LIMITS.DEFAULT_BYTES
       const maxPastedCharacters = finitePositiveAttribute(
         policyElement,
         'data-paste-max-characters'
       )
-      const admission = assessTextPaste({
-        pastedText: text,
-        maxPastedBytes,
-        maxPastedCharacters,
-      })
-      if (admission.accepted) return
+      const textAdmission =
+        text && !projectsTextResult
+          ? assessTextPaste({
+              pastedText: text,
+              maxPastedBytes,
+              maxPastedCharacters,
+            })
+          : null
+      const htmlPolicyElement = event.target.closest('[data-paste-max-html-bytes]')
+      const maxPastedHtmlBytes = finitePositiveAttribute(
+        htmlPolicyElement,
+        'data-paste-max-html-bytes'
+      )
+      const html = maxPastedHtmlBytes ? (event.clipboardData?.getData('text/html') ?? '') : ''
+      const htmlAdmission =
+        html && maxPastedHtmlBytes
+          ? assessTextPaste({ pastedText: html, maxPastedBytes: maxPastedHtmlBytes })
+          : null
+      const rejection =
+        textAdmission && !textAdmission.accepted
+          ? textAdmission
+          : htmlAdmission && !htmlAdmission.accepted
+            ? htmlAdmission
+            : null
+      if (!rejection) return
 
       event.preventDefault()
       event.stopImmediatePropagation()
       const limit =
-        admission.reason === 'pasted-characters'
-          ? `${admission.limit.toLocaleString()} characters`
-          : formatPasteLimit(admission.limit)
+        rejection.reason === 'pasted-characters'
+          ? `${rejection.limit.toLocaleString()} characters`
+          : formatPasteLimit(rejection.limit)
       notifyRef.current.warning('Paste is too large for this editor', {
         description: `The clipboard content was left unchanged. This editor supports up to ${limit}.`,
       })

apps/sim/app/workspace/[workspaceId]/files/components/file-viewer/rich-markdown-editor/paste-admission.test.ts

@@ -4,8 +4,11 @@
 import { Editor } from '@tiptap/core'
 import { TextSelection } from '@tiptap/pm/state'
 import { afterEach, describe, expect, it, vi } from 'vitest'
-import { createMarkdownContentExtensions } from './extensions'
-import { createRichMarkdownPasteAdmission } from './paste-admission'
+import { createMarkdownContentExtensions } from '@/app/workspace/[workspaceId]/files/components/file-viewer/rich-markdown-editor/extensions'
+import {
+  assessRawMarkdownPaste,
+  createRichMarkdownPasteAdmission,
+} from '@/app/workspace/[workspaceId]/files/components/file-viewer/rich-markdown-editor/paste-admission'
 
 let editor: Editor | null = null
 
@@ -14,10 +17,16 @@ afterEach(() => {
   editor = null
 })
 
-function runPaste(ed: Editor, text: string): { handled: boolean; prevented: boolean } {
+function runPaste(ed: Editor, text: string, html = ''): { handled: boolean; prevented: boolean } {
   let prevented = false
   const event = {
-    clipboardData: { getData: (type: string) => (type === 'text/plain' ? text : '') },
+    clipboardData: {
+      getData: (type: string) => {
+        if (type === 'text/plain') return text
+        if (type === 'text/html') return html
+        return ''
+      },
+    },
     preventDefault: () => {
       prevented = true
     },
@@ -31,6 +40,20 @@ function runPaste(ed: Editor, text: string): { handled: boolean; prevented: bool
 }
 
 describe('rich Markdown paste admission', () => {
+  it('rejects a raw-text append whose projected result exceeds the limit', () => {
+    expect(
+      assessRawMarkdownPaste(
+        {
+          pastedText: '56789',
+          currentText: '123456',
+          selectionStart: 6,
+          selectionEnd: 6,
+        },
+        10
+      )
+    ).toEqual({ accepted: false, reason: 'result-bytes', actual: 11, limit: 10 })
+  })
+
   it('rejects before downstream paste parsing when projected bytes exceed the document limit', () => {
     const onRejected = vi.fn()
     editor = new Editor({
@@ -88,4 +111,51 @@ describe('rich Markdown paste admission', () => {
 
     expect(runPaste(editor, '1234567890')).toEqual({ handled: false, prevented: false })
   })
+
+  it('rejects oversized rich HTML before downstream parsing', () => {
+    const onRejected = vi.fn()
+    editor = new Editor({
+      extensions: [
+        ...createMarkdownContentExtensions(),
+        createRichMarkdownPasteAdmission({
+          maxResultBytes: 10,
+          getCurrentText: () => '',
+          onRejected,
+        }),
+      ],
+      content: '<p></p>',
+    })
+
+    expect(runPaste(editor, 'x', '<strong>abc</strong>')).toEqual({
+      handled: true,
+      prevented: true,
+    })
+    expect(onRejected).toHaveBeenCalledOnce()
+  })
+
+  it('rejects a paste whose canonical Markdown result exceeds the limit', () => {
+    const onRejected = vi.fn()
+    editor = new Editor({
+      extensions: [
+        ...createMarkdownContentExtensions(),
+        createRichMarkdownPasteAdmission({
+          maxResultBytes: 10,
+          getCurrentText: () => '123456',
+          onRejected,
+        }),
+      ],
+      content: '<p>123456</p>',
+    })
+    const strong = editor.schema.marks.bold.create()
+    const transaction = editor.state.tr
+      .replaceSelectionWith(editor.schema.text('abc', [strong]), false)
+      .setMeta('uiEvent', 'paste')
+
+    expect(editor.markdown.serialize(transaction.doc.toJSON())).toBe('**abc**123456')
+    expect(transaction.getMeta('uiEvent')).toBe('paste')
+    editor.view.dispatch(transaction)
+
+    expect(editor.getText()).toBe('123456')
+    expect(onRejected).toHaveBeenCalledOnce()
+  })
 })