Toggle buttons

[alinepuresv]

Sometimes it feels like the toggle buttons aren't working.

Here are the ones I'm talking about:

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@claude can you take a look at this? Just test them out and verify that clicking them toggles between the code and preview tabs.

[claude]

Claude finished @alinepuresv's task in 11m 50s —— View job • claude/issue-5-20260227-0809 • Create PR ➔

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Analysis & Fix: Toggle buttons

• Gather context and understand the request
• Explore toggle button components in the codebase
• Fix PreviewFrame.tsx useEffect dependency cycle
• Write tests to verify toggle behavior works correctly
• Commit and push changes

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What I found

The toggle buttons themselves work correctly — the MainContent component uses a Radix UI Tabs controlled component (value={activeView} + onValueChange) that properly updates React state, and the conditional render switches the view. The logic was sound.

However, I found a real bug in PreviewFrame.tsx that was causing unnecessary re-render cascades every time a file was created or updated:

The problem (PreviewFrame.tsx line 99, original):

}, [refreshTrigger, getAllFiles, entryPoint, error, isFirstLoad]);
//                                            ^^^^   ^^^^^^^^^^^
//                    both are SET inside the effect — circular dependency!

error and isFirstLoad were listed as dependencies, but they were also set inside the effect itself. React sees a state change → re-runs the effect → sets the same state again → potentially re-runs again. This created 2–3 extra effect runs per file system change, causing the preview area to repeatedly re-render right when you might be trying to interact with the UI.

The fix:

• Replaced useState(true) for isFirstLoad with useRef(true) — refs update without triggering re-renders or invalidating effect closures
• Removed error and isFirstLoad from the dependency array
• Removed the now-redundant early setError(null) guard (the success path already handles it)

Tests added

New file src/app/__tests__/main-content.test.tsx with 5 tests that directly verify the toggle:

• Preview view shown by default
• Preview tab marked data-state="active" initially
• Clicking Code switches to code view (shows editor + file tree, hides preview)
• Code tab becomes active, Preview tab becomes inactive
• Clicking Preview switches back
• Can toggle back and forth multiple times
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