From e5899d81c47bf66318f26679fce4768a4eae7ca9 Mon Sep 17 00:00:00 2001
From: Michael Chihlas <michael@chihlas.com>
Date: Sat, 14 Mar 2026 19:34:45 -0400
Subject: [PATCH] fix: param block detection with nested parens + cursor
 alignment

The paren depth counter started at 0 and immediately matched before
any '(' was counted, causing param blocks to be detected as ending
on line 0. Added foundOpen flag to require at least one '(' before
checking for balanced depth.

For cursor alignment: switch both textarea and overlay to whitespace-pre
with wrap=off, use explicit 21px line-height (14px * 1.5), and strip
all default pre element margins/padding/borders.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
---
 frontend/src/components/script-editor/ScriptBodyEditor.tsx | 5 +++--
 frontend/src/lib/scriptParameterDetector.ts                | 5 +++--
 2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/frontend/src/components/script-editor/ScriptBodyEditor.tsx b/frontend/src/components/script-editor/ScriptBodyEditor.tsx
index e16246d8..762311cc 100644
--- a/frontend/src/components/script-editor/ScriptBodyEditor.tsx
+++ b/frontend/src/components/script-editor/ScriptBodyEditor.tsx
@@ -37,7 +37,7 @@ export function ScriptBodyEditor({ value, onChange, disabled }: Props) {
     <div className="relative rounded-xl border border-border overflow-hidden">
       {/* Highlighted overlay (read-only visual layer) — scroll synced to textarea */}
       <div ref={overlayRef} className="absolute inset-0 pointer-events-none overflow-hidden p-4">
-        <PowerShellHighlighter script={value || ' '} className="font-label text-sm leading-[1.5] whitespace-pre-wrap break-words m-0" />
+        <PowerShellHighlighter script={value || ' '} className="font-label text-sm leading-[21px] whitespace-pre m-0 p-0 border-0" />
       </div>
 
       {/* Editable textarea (transparent text, visible caret) */}
@@ -48,8 +48,9 @@ export function ScriptBodyEditor({ value, onChange, disabled }: Props) {
         onScroll={handleScroll}
         onKeyDown={handleTab}
         disabled={disabled}
+        wrap="off"
         spellCheck={false}
-        className="relative z-10 w-full min-h-[300px] resize-y font-label text-sm leading-[1.5] bg-transparent text-transparent caret-foreground p-4 whitespace-pre-wrap break-words focus:outline-none focus:ring-1 focus:ring-[rgba(6,182,212,0.2)] disabled:cursor-not-allowed disabled:opacity-50"
+        className="relative z-10 w-full min-h-[300px] resize-y font-label text-sm leading-[21px] bg-transparent text-transparent caret-foreground p-4 whitespace-pre overflow-auto focus:outline-none focus:ring-1 focus:ring-[rgba(6,182,212,0.2)] disabled:cursor-not-allowed disabled:opacity-50"
         placeholder="# Enter your PowerShell script here…&#10;# Use {{ param_name }} for parameter placeholders"
       />
     </div>
diff --git a/frontend/src/lib/scriptParameterDetector.ts b/frontend/src/lib/scriptParameterDetector.ts
index bce72650..cbf631ec 100644
--- a/frontend/src/lib/scriptParameterDetector.ts
+++ b/frontend/src/lib/scriptParameterDetector.ts
@@ -155,11 +155,12 @@ function findScriptLevelParamBlock(script: string): { start: number; end: number
 
     if (functionBraceDepth === 0 && /^param\s*\(/i.test(trimmed) && paramStart === -1) {
       paramStart = i
+      let foundOpen = false
       for (let j = i; j < lines.length; j++) {
         for (const ch of lines[j]) {
-          if (ch === '(') parenDepth++
+          if (ch === '(') { parenDepth++; foundOpen = true }
           if (ch === ')') parenDepth--
-          if (parenDepth === 0 && paramStart !== -1) {
+          if (foundOpen && parenDepth === 0) {
             return { start: paramStart, end: j }
           }
         }