fix: clean newline paste thingy

ui-tui/src/app.tsx

@@ -29,6 +29,7 @@ import {
   isTransientTrailLine,
   pick,
   sameToolTrailGroup,
+  stripTrailingPasteNewlines,
   toolTrailLabel
 } from './lib/text.js'
 import { DEFAULT_THEME, fromSkin, type Theme } from './theme.js'
@@ -784,14 +785,19 @@ export function App({ gw }: { gw: GatewayClient }) {
         void paste(true)
       }
 
-      if (!text) {
+      const cleanedText = stripTrailingPasteNewlines(text)
+
+      if (!cleanedText) {
         return null
       }
 
-      const lineCount = text.split('\n').length
+      const lineCount = cleanedText.split('\n').length
 
-      if (text.length < LARGE_PASTE.chars && lineCount < LARGE_PASTE.lines) {
-        return { cursor: cursor + text.length, value: value.slice(0, cursor) + text + value.slice(cursor) }
+      if (cleanedText.length < LARGE_PASTE.chars && lineCount < LARGE_PASTE.lines) {
+        return {
+          cursor: cursor + cleanedText.length,
+          value: value.slice(0, cursor) + cleanedText + value.slice(cursor)
+        }
       }
 
       pasteCounterRef.current++
@@ -806,13 +812,13 @@ export function App({ gw }: { gw: GatewayClient }) {
         [
           ...prev,
           {
-            charCount: text.length,
+            charCount: cleanedText.length,
             createdAt: Date.now(),
             id,
-            kind: classifyPaste(text),
+            kind: classifyPaste(cleanedText),
             lineCount,
             mode,
-            text
+            text: cleanedText
           }
         ].slice(-24)
       )

ui-tui/src/lib/text.test.ts

@@ -0,0 +1,18 @@
+import { describe, expect, it } from 'vitest'
+
+import { stripTrailingPasteNewlines } from './text.js'
+
+describe('stripTrailingPasteNewlines', () => {
+  it('removes trailing newline runs from pasted text', () => {
+    expect(stripTrailingPasteNewlines('alpha\n')).toBe('alpha')
+    expect(stripTrailingPasteNewlines('alpha\nbeta\n\n')).toBe('alpha\nbeta')
+  })
+
+  it('preserves interior newlines', () => {
+    expect(stripTrailingPasteNewlines('alpha\nbeta\ngamma')).toBe('alpha\nbeta\ngamma')
+  })
+
+  it('preserves newline-only pastes', () => {
+    expect(stripTrailingPasteNewlines('\n\n')).toBe('\n\n')
+  })
+})

ui-tui/src/lib/text.ts

@@ -49,6 +49,8 @@ export const thinkingPreview = (reasoning: string, mode: ThinkingMode, max: numb
   return !text || mode === 'collapsed' ? '' : mode === 'full' ? text : compactPreview(text, max)
 }
 
+export const stripTrailingPasteNewlines = (text: string) => (/[^\n]/.test(text) ? text.replace(/\n+$/, '') : text)
+
 export const toolTrailLabel = (name: string) =>
   name
     .split('_')