Reuse component shadow-root style nodes across re-renders#62
Merged
JosunLP merged 4 commits intodevelopmentfrom Mar 13, 2026
Merged
Reuse component shadow-root style nodes across re-renders#62JosunLP merged 4 commits intodevelopmentfrom
JosunLP merged 4 commits intodevelopmentfrom
Conversation
Co-authored-by: JosunLP <20913954+JosunLP@users.noreply.github.com>
Co-authored-by: JosunLP <20913954+JosunLP@users.noreply.github.com>
Copilot
AI
changed the title
[WIP] [FR-8] Improve style element handling on re-render
Reuse component shadow-root style nodes across re-renders
Mar 13, 2026
Contributor
There was a problem hiding this comment.
Pull request overview
This PR updates the Web Components render path so defineComponent() preserves the component-managed shadow-root <style> element across attribute-driven re-renders, avoiding unnecessary DOM churn and ensuring a stable style node.
Changes:
- Preserve and reuse the component-owned shadow-root
<style>node acrossrender(true)updates by tagging it withdata-bquery-component-style. - Add a regression test that verifies style node identity reuse, ensures only one
<style>remains after update, and confirms rendered content updates.
Reviewed changes
Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.
| File | Description |
|---|---|
src/component/component.ts |
Reuses an existing style[data-bquery-component-style] node after shadowRoot.innerHTML resets, preventing style element recreation on re-render. |
tests/component.test.ts |
Adds a focused test to validate style node reuse across attribute-triggered re-renders. |
Collaborator
|
@copilot apply changes based on the comments in this thread |
Co-authored-by: JosunLP <20913954+JosunLP@users.noreply.github.com>
Contributor
Author
Applied in 8f0bb2e. The regression test now targets |
Contributor
There was a problem hiding this comment.
Pull request overview
This PR reduces DOM churn in the component module by preserving the component-owned <style> node across attribute-driven re-renders, instead of recreating it on every render. This improves render efficiency and avoids unnecessary style node replacement.
Changes:
- Preserve and re-prepend an existing shadow-root style node (marked with
data-bquery-component-style) during re-renders. - Add a regression test ensuring the same style element instance is reused and remains singular after an attribute-triggered update.
Reviewed changes
Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.
| File | Description |
|---|---|
src/component/component.ts |
Captures the existing component style node before shadowRoot.innerHTML replacement and reinserts it after render, tagging newly-created style nodes with data-bquery-component-style. |
tests/component.test.ts |
Adds a test verifying the style node instance is reused across attribute-triggered re-renders and that only one style tag exists post-update. |
JosunLP
added a commit
that referenced
this pull request
Mar 15, 2026
* Add `bool()` support for boolean attributes in component templates (#55) Co-authored-by: JosunLP <20913954+JosunLP@users.noreply.github.com> Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com> Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com> Co-authored-by: Jonas Pfalzgraf <info@josunlp.de> * Add typed state generics to component definitions (#56) Co-authored-by: JosunLP <20913954+JosunLP@users.noreply.github.com> Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com> Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com> Co-authored-by: Jonas Pfalzgraf <info@josunlp.de> * Pass attribute change metadata to component `updated()` hooks (#58) Co-authored-by: JosunLP <20913954+JosunLP@users.noreply.github.com> Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com> Co-authored-by: Jonas Pfalzgraf <info@josunlp.de> * Add per-component sanitizer overrides for component render output (#57) * Initial plan * feat: add per-component sanitizer options Co-authored-by: JosunLP <20913954+JosunLP@users.noreply.github.com> * docs: clarify component sanitizer baseline Co-authored-by: JosunLP <20913954+JosunLP@users.noreply.github.com> * docs: warn about sensitive component sanitizer opts Co-authored-by: JosunLP <20913954+JosunLP@users.noreply.github.com> * test: cover sanitizer allowTags overrides Co-authored-by: JosunLP <20913954+JosunLP@users.noreply.github.com> * perf: precompute component sanitizer allowlists Co-authored-by: JosunLP <20913954+JosunLP@users.noreply.github.com> --------- Signed-off-by: Jonas Pfalzgraf <info@josunlp.de> Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com> Co-authored-by: JosunLP <20913954+JosunLP@users.noreply.github.com> Co-authored-by: Jonas Pfalzgraf <info@josunlp.de> * Pass previous props into component `beforeUpdate` (#59) * Initial plan * Add previous props to beforeUpdate hook Co-authored-by: JosunLP <20913954+JosunLP@users.noreply.github.com> * Refine beforeUpdate old props implementation Co-authored-by: JosunLP <20913954+JosunLP@users.noreply.github.com> * Fix beforeUpdate typing regressions Co-authored-by: JosunLP <20913954+JosunLP@users.noreply.github.com> --------- Signed-off-by: Jonas Pfalzgraf <info@josunlp.de> Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com> Co-authored-by: JosunLP <20913954+JosunLP@users.noreply.github.com> Co-authored-by: Jonas Pfalzgraf <info@josunlp.de> * Add explicit signal subscriptions to `component()` renders (#60) * Initial plan * feat: add component signal subscriptions Co-authored-by: JosunLP <20913954+JosunLP@users.noreply.github.com> * chore: document signal subscription tracking Co-authored-by: JosunLP <20913954+JosunLP@users.noreply.github.com> * fix: address signal integration review feedback Co-authored-by: JosunLP <20913954+JosunLP@users.noreply.github.com> * fix: tighten component signal typing Co-authored-by: JosunLP <20913954+JosunLP@users.noreply.github.com> * fix: resolve eslint failure in component signal test Co-authored-by: JosunLP <20913954+JosunLP@users.noreply.github.com> * fix: handle reconnect lifecycle and signal effect errors Co-authored-by: JosunLP <20913954+JosunLP@users.noreply.github.com> * fix: preserve reconnect signal wiring after hook errors Co-authored-by: JosunLP <20913954+JosunLP@users.noreply.github.com> * fix: skip beforeUpdate for signal rerenders Co-authored-by: JosunLP <20913954+JosunLP@users.noreply.github.com> --------- Signed-off-by: Jonas Pfalzgraf <info@josunlp.de> Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com> Co-authored-by: JosunLP <20913954+JosunLP@users.noreply.github.com> Co-authored-by: Jonas Pfalzgraf <info@josunlp.de> * Add trusted sanitized fragments for `safeHtml` composition (#61) * Initial plan * feat: add trusted safeHtml fragment support Co-authored-by: JosunLP <20913954+JosunLP@users.noreply.github.com> * chore: finalize trusted safeHtml support Co-authored-by: JosunLP <20913954+JosunLP@users.noreply.github.com> * docs: address trusted safeHtml review feedback Co-authored-by: JosunLP <20913954+JosunLP@users.noreply.github.com> * docs: fix second trusted safeHtml review follow-up Co-authored-by: JosunLP <20913954+JosunLP@users.noreply.github.com> * refactor: split trusted html helpers from sanitizer Co-authored-by: JosunLP <20913954+JosunLP@users.noreply.github.com> * refactor: tighten trusted html branding Co-authored-by: JosunLP <20913954+JosunLP@users.noreply.github.com> * docs: tighten trusted html internals Co-authored-by: JosunLP <20913954+JosunLP@users.noreply.github.com> --------- Signed-off-by: Jonas Pfalzgraf <info@josunlp.de> Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com> Co-authored-by: JosunLP <20913954+JosunLP@users.noreply.github.com> Co-authored-by: Jonas Pfalzgraf <info@josunlp.de> * Reuse component shadow-root style nodes across re-renders (#62) * Initial plan * fix: reuse component style element on rerender Co-authored-by: JosunLP <20913954+JosunLP@users.noreply.github.com> * chore: finalize component style reuse fix Co-authored-by: JosunLP <20913954+JosunLP@users.noreply.github.com> * test: tighten style reuse regression assertions Co-authored-by: JosunLP <20913954+JosunLP@users.noreply.github.com> --------- Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com> Co-authored-by: JosunLP <20913954+JosunLP@users.noreply.github.com> * Add `@bquery/bquery/storybook` template helpers for Storybook stories (#63) * Initial plan * feat: add storybook template helper Co-authored-by: JosunLP <20913954+JosunLP@users.noreply.github.com> * docs: clarify storybook when fallback behavior Co-authored-by: JosunLP <20913954+JosunLP@users.noreply.github.com> * fix: keep storybook helpers out of full bundle Co-authored-by: JosunLP <20913954+JosunLP@users.noreply.github.com> * fix: sanitize storybook helper output Co-authored-by: JosunLP <20913954+JosunLP@users.noreply.github.com> * test: tighten storybook helper security coverage Co-authored-by: JosunLP <20913954+JosunLP@users.noreply.github.com> * feat: enhance storyHtml with improved boolean attribute handling and sanitization tests * fix: update storyHtml example to reflect correct boolean attribute output * fix: defensive tag delimiter and parser comments per code review Co-authored-by: JosunLP <20913954+JosunLP@users.noreply.github.com> --------- Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com> Co-authored-by: JosunLP <20913954+JosunLP@users.noreply.github.com> * chore: release version 1.6.0 - Update CHANGELOG.md for version 1.6.0 release notes including added features, changes, fixes, and security improvements. - Enhance README.md to document new boolean attribute helpers and Storybook integration. - Update bun.lock to reflect dependency upgrades for Storybook and happy-dom. - Modify definition.md to include new Storybook helpers and component state management features. - Revise components.md to demonstrate new boolean attribute handling and typed state in components. - Update getting-started.md with Storybook authoring examples and improved module descriptions. - Enhance security.md to clarify sanitization practices and introduce trusted fragment handling. - Revise index.md to highlight new Storybook helpers in the feature list. - Update llms.txt to reflect the new version 1.6.0. - Bump version in package.json to 1.6.0 and update devDependencies for Storybook. * Address review feedback for test setup, test type coverage, and component state keys (#65) * Initial plan * Address review feedback for test typing and setup Co-authored-by: JosunLP <20913954+JosunLP@users.noreply.github.com> * Finalize review feedback fixes Co-authored-by: JosunLP <20913954+JosunLP@users.noreply.github.com> * Export component state key type Co-authored-by: JosunLP <20913954+JosunLP@users.noreply.github.com> * Default component state key generic Co-authored-by: JosunLP <20913954+JosunLP@users.noreply.github.com> --------- Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com> Co-authored-by: JosunLP <20913954+JosunLP@users.noreply.github.com> * Tighten component/state update semantics and Storybook attribute sanitization (#66) * Initial plan * fix review follow-up for state updates and storybook sanitization Co-authored-by: JosunLP <20913954+JosunLP@users.noreply.github.com> * fix storybook attribute value scanning Co-authored-by: JosunLP <20913954+JosunLP@users.noreply.github.com> * fix storybook interpolation boundary parsing Co-authored-by: JosunLP <20913954+JosunLP@users.noreply.github.com> * docs align storybook attribute scan jsdoc Co-authored-by: JosunLP <20913954+JosunLP@users.noreply.github.com> --------- Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com> Co-authored-by: JosunLP <20913954+JosunLP@users.noreply.github.com> --------- Signed-off-by: Jonas Pfalzgraf <info@josunlp.de> Co-authored-by: Copilot <198982749+Copilot@users.noreply.github.com> Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
defineComponent()was rebuilding the shadow-root<style>element on every attribute-driven re-render. That churn discarded the existing style node instead of preserving it across updates.Render path
<style>element after render instead of creating a new onedata-bquery-component-styleso the component only manages its own stylesheetRegression coverage
<style>node instance survives an attribute-triggered re-renderResulting behavior
Screenshot
same node reused: true💡 You can make Copilot smarter by setting up custom instructions, customizing its development environment and configuring Model Context Protocol (MCP) servers. Learn more Copilot coding agent tips in the docs.