fix(CodeBlock): Show Action Buttons on Hover

[dustinhealy]

Why?

CodeBlock action buttons (copy, wrap lines) are positioned absolutely over the code content, causing text overlap on long first lines. This is especially noticeable when both buttons are visible.

How?

• Buttons are now hidden by default (opacity: 0) and fade in on hover or focus-within (opacity: 1 with 0.15s ease transition)
• Buttons get a semi-opaque background pill matching the code block's theme background, so any code behind them is obscured when visible
• Small border-radius and padding on the button container for a clean pill appearance

Contribution checklist?

• You've done enough research before writing
• You have reviewed the PR

[changeset-bot]

🦋 Changeset detected

Latest commit: 1566b8d

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@clickhouse/click-ui	Minor

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Click here if you're a maintainer who wants to add another changeset to this PR

[github-actions]

Claude finished @dustinhealy's task in 1m 27s —— View job

---

Code Review: fix(CodeBlock): Show Action Buttons on Hover

• Gather context and read changed files
• Review code changes
• Post findings

---

Nice approach overall — hiding buttons by default and fading them in on hover/focus is a clean UX improvement. A few things need attention before merging:

---

🚨 Must Fix

• CodeBlock.tsx (line 95): transition: opacity 0.15s ease doesn't respect prefers-reduced-motion. Per CONVENTIONS.md: "Respect prefers-reduced-motion for animations". This is mandatory for the component library. Add:

  @media (prefers-reduced-motion: reduce) {
    transition: none;
  }

  Fix this →

• Changeset description mismatch: .changeset/fix-codeblock-button-overlap.md says "Adds right padding to the highlighted code area proportional to the number of action buttons displayed" — that's from a different implementation strategy, not what this PR does. Update it to describe the actual change (buttons hidden by default, revealed on hover/focus-within with semi-opaque background). Fix this →

• CodeBlock.tsx (line 96–97): border-radius: 0.25rem and padding: 0.25rem are hardcoded. Conventions require all sizing values to come from theme tokens. The codeblock theme already has theme.click.codeblock.radii.all (0.25rem) — use that. Fix this →

---

💡 Suggestions (non-blocking)

• ${bg}e6 hex concatenation (CodeBlock.tsx line 105): Appending e6 to produce an 8-digit hex opacity works for the current tokens (all 6-digit hex values like #282828 and #f6f7fa), but it would silently break if any token were ever expressed as rgb(...), hsl(...), or a 3-digit hex. Consider color-mix(in srgb, ${bg} 90%, transparent) for a more robust approach — it's widely supported in modern browsers.

• The ButtonContainer buttons stay in the tab order even at opacity: 0. The focus-within trick correctly surfaces them when keyboard-focused, so this is fine for accessibility — just confirming it was intentional.

---

[github-actions]

Claude finished @dustinhealy's task in 1m 0s —— View job

---

Reviewing PR: fix(CodeBlock): Show Action Buttons on Hover

• Gather context and read changed files
• Review code changes
• Post findings

---

Nice approach — hiding the buttons by default and fading them in on hover/focus-within is clean and solves the overlap well. A few things to address:

🚨 Must Fix

• CodeBlock.tsx line 57 — Fragile hex alpha concatenation: background: ${bg}e6 appends e6 directly to the token value. This assumes the token is always a 6-digit hex string — if it ever resolves to rgb(...), hsl(...), or a named color it will produce invalid CSS silently. Use CSS color-mix() or opacity on a wrapper instead:

  background: ${bg};
  opacity: 0.9; // on a wrapper, not the container with opacity:0

  Or, if styled-components is available, wrap in a separate element without the opacity animation, or check if the design system provides an --alpha token. Fix this →

♿ Accessibility

• Missing prefers-reduced-motion support (CONVENTIONS.md mandates it): The transition: opacity 0.15s ease will animate for users who've opted out of motion. Add:

  @media (prefers-reduced-motion: reduce) {
    transition: none;
  }

  Fix this →

💡 Suggestions (non-blocking)

• Hardcoded spacing (border-radius: 0.25rem, padding: 0.25rem): Per CONVENTIONS.md, spacing/sizes should come from theme.click.* tokens rather than hardcoded rem values. Worth checking if the design system has a relevant radius or space token.

• Changeset description mismatch: The changeset says "Adds right padding to the highlighted code area proportional to the number of action buttons displayed" — but the actual implementation uses hover-reveal with a background pill, not padding. Worth updating it to accurately describe what shipped (helps with changelogs downstream).

[github-actions]

Claude finished @dustinhealy's task in 1m 29s —— View job

---

Code Review: fix(CodeBlock): Show Action Buttons on Hover

• Gather context and read changed files
• Read CONVENTIONS.md and repo guidelines
• Review code changes
• Post findings

---

Nice approach — hiding the buttons by default and fading them in on hover/focus-within is clean and solves the overlap well. Three things need to be addressed before merging:

---

🚨 Must Fix

• CodeBlock.tsx line 47 — Missing prefers-reduced-motion support: transition: opacity 0.15s ease has no reduced-motion override. CONVENTIONS.md mandates: "Respect prefers-reduced-motion for animations." Add inside ButtonContainer:

  @media (prefers-reduced-motion: reduce) {
    transition: none;
  }

  Fix this →

• CodeBlock.tsx line 48 — Hardcoded border-radius: border-radius: 0.25rem should be border-radius: ${({ theme }) => theme.click.codeblock.radii.all} — the token already exists and equals 0.25rem. CONVENTIONS.md: "NEVER hardcode colors, sizes, or spacing." Fix this →

• Stale changeset description in .changeset/fix-codeblock-button-overlap.md: Still says "Adds right padding to the highlighted code area proportional to the number of action buttons displayed" — that's the old discarded approach. Update to accurately describe what shipped (buttons hidden by default, revealed on hover/focus-within with a semi-opaque background). Fix this →

---

💡 Suggestions (non-blocking)

• ${bg}e6 hex concatenation (CodeBlock.tsx line 57): Works correctly for the current tokens (#282828, #f6f7fa), but would silently produce invalid CSS if any token were ever expressed as rgb(...), hsl(...), or a 3-digit hex. Consider color-mix(in srgb, ${bg} 90%, transparent) as a more robust alternative — it's well-supported in modern browsers.

• padding: 0.25rem (CodeBlock.tsx line 49): No exact codeblock space token for this value. Worth checking if a general space token covers it, or consider adding a codeblock-specific token (e.g., theme.click.codeblock.space.buttonPadding) if the design team wants to control it.

[github-actions]

Claude finished @dustinhealy's task in 52s —— View job

---

Code Review: fix(CodeBlock): Show Action Buttons on Hover

• Gather context and read changed files
• Review latest code changes
• Post findings

---

All the feedback from previous reviews has been addressed — nice follow-through! 🙌

✅ Previously flagged issues — now fixed

• prefers-reduced-motion: @media (prefers-reduced-motion: reduce) { transition: none; } added correctly (lines 48–50)
• border-radius: now ${theme.click.codeblock.radii.all} (line 56) ✅
• padding: now ${theme.sizes[1]} (line 57) ✅
• Hex alpha hack: replaced with color-mix(in srgb, ${bg} 90%, transparent) (line 60) ✅
• Changeset description: accurately reflects the actual implementation ✅

---

💡 Suggestion (non-blocking)

• gap: 0.625rem (CodeBlock.tsx line 55): This is the one remaining hardcoded size. CONVENTIONS.md says "NEVER hardcode colors, sizes, or spacing." Worth replacing with a theme token if one exists (e.g., theme.click.codeblock.space.* or a general space token), or adding one. Low priority since it doesn't affect correctness.

---

Everything else looks great. The hover-reveal approach is clean, keyboard accessible via focus-within, and the color-mix() background is robust. Ready to merge once the gap is considered (or consciously left as-is).

[github-actions]

Claude finished @dustinhealy's task in 1m 23s —— View job

---

Code Review: fix(CodeBlock): Show Action Buttons on Hover

• Gather context and read changed files
• Review latest code changes
• Post findings

---

All previous blockers have been resolved — great follow-through! 🙌

✅ Previously flagged issues — now fixed

• prefers-reduced-motion: @media (prefers-reduced-motion: reduce) { transition: none; } added ✅
• border-radius: now theme.click.codeblock.radii.all ✅
• padding: now theme.sizes[1] ✅
• Hex alpha hack: replaced with color-mix(in srgb, ${bg} 90%, transparent) ✅
• Changeset description: accurately reflects the actual implementation ✅

---

💡 Suggestion (non-blocking)

• gap: 0.625rem (CodeBlock.tsx line 55): One remaining hardcoded size. No exact match exists in theme.sizes (sizes[3] is 0.5rem, sizes[4] is 0.75rem) and theme.click.codeblock.space.gap (1.5rem) serves a different purpose. Options: use the nearest token, or add a dedicated theme.click.codeblock.space.buttonGap token. Either way, low priority — doesn't affect correctness or behavior.

---

Everything else looks solid. The hover-reveal is clean, keyboard-accessible via focus-within, and the color-mix() background is robust. Ready to merge once the gap is addressed or consciously left as-is.

[github-actions]

Claude finished @dustinhealy's task in 2m 9s —— View job

---

Code Review: fix(CodeBlock): Show Action Buttons on Hover

• Gather context and read changed files
• Review code changes
• Post findings

---

Great follow-through on the previous feedback — the core implementation is solid. One potential bug slipped through, and there's one remaining hardcoded value worth addressing.

---

🐛 Possible Bug

• CodeBlock.tsx line 57 — Wrong sizes index for padding: ${theme.sizes[1]} resolves to '1px' (not '0.25rem'). The sizes token array is {'0': '0', '1': '1px', '2': '0.25rem', ...} — so the original padding: 0.25rem intent maps to theme.sizes[2]. With 1px, the semi-opaque pill background will be nearly flush with the icon buttons, losing the intended breathing room. Fix this →

---

💡 Suggestions (non-blocking)

• gap: 0.625rem (CodeBlock.tsx line 55): Still the one remaining hardcoded size — no exact token maps to 10px (sizes[3] = 0.5rem, sizes[4] = 0.75rem). Nearest fit is theme.sizes[4] (0.75rem) or a dedicated theme.click.codeblock.space.buttonGap token, but consciously leaving it is also fine.

• No tests for new hover/focus behavior: There's no CodeBlock.test.tsx (pre-existing gap), but the new opacity/focus-within logic is a good candidate for a quick accessibility smoke test.

---

✅ Previously flagged — all confirmed fixed

• prefers-reduced-motion media query ✅
• border-radius using theme.click.codeblock.radii.all ✅
• color-mix(in srgb, ${bg} 90%, transparent) replacing the fragile hex concatenation ✅
• Changeset description accurately describes the implementation ✅
• top/right positioning using theme.click.codeblock.space.y/x ✅

[workflow-authentication-public]

📚 Storybook Preview Deployed

✅ Preview URL: https://click-q2pc0yj7w-clickhouse.vercel.app

Built from commit: ad67d9fc4ee2af5bd966076a8bbf7de83a1443f6

[punkbit]

@dustinhealy Do me a favour. Change target branch to "main". We prefer to push changes to "main" as the source of truth. If a pre-release is open, we then cherry-pick; this way, we don't lose track of any changes :)

[danielclickh]

Thanks for the work on this @dustinhealy ! I do have two suggestions to help with accessibility:

1. Make it sure it's visible when the codeblock is active (this way keyboard users can see that)
2. Add ARIA labels

[gjones]

@dustinhealy are we still working on this one? Needs some help getting it over the finish line?

[dustinhealy]

@gjones thanks for ping. This one obviously got lost - I will pick back up this weekend and get it ready for final review by Monday.

[dustinhealy]

@gjones this is ready whenever - not sure how to clear the pending UI test CI action