hermes-config/skills/self-hosting/shop-pro-quote/references/js-pitfalls.md

ShopProQuote JS Pitfalls

const redeclaration in large single-file scripts

dashboard.js is a large file (~4000 lines) with many functions sharing the same closure scope. When a const variable is declared twice in the same block, it throws a fatal parse error that prevents the ENTIRE script from loading. The browser won't execute any of it.

Real bug — Daily Briefing stuck on "Loading..."

In dashboard.js, const briefingText was declared twice in the same try block:

// First declaration (line 3926) — extracting from API response
const briefingText = dsResult.choices?.[0]?.message?.content?.trim() || '';

// ... (HTML rendering) ...

// Second declaration (line 3944) — caching
const briefingText = contentDiv.textContent || '';

This parse error stopped dashboard.js from loading entirely. The fallback inline script in index.html kept polling for window.generateDailyBriefing (which was never defined), showing "Loading briefing..." forever.

Fix

Rename the second variable unambiguously:

const finalBriefingText = contentDiv.textContent || '';

Prevention

• When editing a function in a large file, check for variable name collisions in the same function scope.
• let declarations in different blocks can share names safely, but const in the same block cannot.
• There is no build step or linter — these errors only surface at runtime. Test in browser console.