fix: allow SSR bootstrap without component styles - #475
Merged
Mohamed Mansour (mohamedmansour) merged 1 commit intoAug 25, 2026
Conversation
Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com> Copilot-Session: febce809-72a9-4daf-bb94-6ee494bed686
Mohamed Mansour (mohamedmansour)
requested review from
Bang Lee (Qusic),
Jane Chu (janechu) and
mcritzjam
August 25, 2026 02:22
Jane Chu (janechu)
approved these changes
Aug 25, 2026
Jane Chu (janechu)
approved these changes
Aug 25, 2026
Mohamed Mansour (mohamedmansour)
merged commit Aug 25, 2026
0305f6c
into
microsoft:main
24 checks passed
Mohamed Mansour (mohamedmansour)
deleted the
mohamedmansour-restore-optional-component-styles
branch
August 25, 2026 02:48
Mohamed Mansour (mohamedmansour)
added a commit
that referenced
this pull request
Aug 25, 2026
## Summary - allocate the condition resolver only for components that evaluate a runtime condition - share the existing empty-array sentinel for absent text, attribute, condition, and repeat metadata in both client wiring and SSR hydration - clear populated binding arrays in place while guarding the shared empty sentinel ## Performance Measured in Chromium with the direct `streaming-browser-bench` lazy-hydration matrix at 10, 100, and 1,000 elements. Each arm ran 60 samples in counterbalanced `baseline → branch → branch → baseline` order with forced-GC CDP heap samples. Both source trees included the same PR #475 runtime fix and differed only in `template-element.ts`. | Mode | Elements | Baseline retained heap | Branch retained heap | Delta | | --- | ---: | ---: | ---: | ---: | | eager | 10 | 214.3 KiB | 214.5 KiB | noise (+0.1%) | | eager | 100 | 335.5 KiB | 326.8 KiB | **-2.6%** | | eager | 1,000 | 1,378.0 KiB | 1,244.6 KiB | **-9.7% (-133.4 KiB)** | | lazy-hydrate | 1,000 | 635.1 KiB | 588.1 KiB | **-7.4% (-47.0 KiB)** | | lazy-render | 1,000 | 652.0 KiB | 605.3 KiB | **-7.2% (-46.7 KiB)** | A separate object-identity probe confirmed exactly four avoided allocations per element: one resolver closure and three empty binding arrays, or **40 / 400 / 4,000 allocations** at 10 / 100 / 1,000 elements. Baseline roots retained `N` resolver functions and `3N` unique empty arrays; the branch retained no resolver on condition-free roots and reused one pre-existing empty sentinel. End-to-end custom-element definition medians remained effectively flat: - eager 1,000: 26.95 ms → 27.25 ms (+0.30 ms) - lazy-hydrate 1,000: 21.70 ms → 21.75 ms (+0.05 ms) - lazy-render 1,000: 21.45 ms → 21.55 ms (+0.10 ms) Bundle size changes by +83 B gzip for eager and +100 B gzip for lazy modes. Exact `body.innerHTML` SHA-256 values matched between baseline and branch at all three scales. ## Validation - `pnpm --dir packages/webui-framework test:unit` - focused Playwright fixtures: 82 passed, 2 skipped - `cargo xtask check` Copilot-Session: 701fdb47-fef7-4cf9-b17f-ed54b1c113dc
Mohamed Mansour (mohamedmansour)
added a commit
that referenced
this pull request
Aug 26, 2026
## Release Bumps WebUI to `0.0.26`. Previous release tag: `v0.0.25` ## Changes since `v0.0.25` Features: - Python hosts now have an official typed PyO3 renderer package with buffered, partial, template, token, and host-driven streaming APIs (feat: add official Python renderer package #453 by @mohamedmansour). - Progressive SSR can place transport-flushed streaming boundaries inside reusable components while preserving component ownership and continuation state (feat: support component-local streaming boundaries #460 by @mohamedmansour). - Components can defer compiler-owned hydration until interaction, with router preload handoff and a combined lazy-render policy (feat: add compiler-driven interaction hydration #485 by @mohamedmansour). - Builds can opt into global Light DOM CSS while preserving explicit authored Shadow roots and deterministic style closures (feat: make Light DOM a global CSS opt-in #429 by @mohamedmansour). - State projection supports application-owned TypeScript 7.0.2 while retaining the TypeScript 6 migration path (feat: support TypeScript 7 projection compilation #452 by @mohamedmansour). - WebUI Press supports layout-scoped compile-time named regions with fallback HTML, state, components, and scripts (feat(press): add compile-time named regions #484 by @mohamedmansour). - FAST v2 and v3 gain plugin-owned local and npm component discovery with validated FAST template transformation (feat: add plugin-owned FAST component discovery #378 by @janechu). Fixes: - Missing condition identifiers are treated as falsy before negation and logical evaluation, aligning SSR with the browser runtime (fix: negate missing condition paths correctly #449 by @mohamedmansour). - FAST route state now scales through escaped scalar kebab-case attributes shared by FAST v2 and v3 (fix: scale FAST route state with scalar attributes #450 by @janechu). - Dynamic Link-mode components wait for native stylesheet readiness across navigation and component assets, preventing unstyled flashes (fix: prevent dynamic component stylesheet flashes #454 by @mohamedmansour). - Authored component definitions defer whenever compiled template metadata has not arrived, including ordinary router navigation (fix: defer authored define() whenever template metadata is missing #461 by @mohamedmansour). - Client structural updates preserve authored order and sibling ownership for shared slots and raw HTML ranges (fix: preserve source order for shared structural slots #465 by @mohamedmansour, fix: preserve siblings around raw HTML updates #466 by @mohamedmansour). - Native-element attributes no longer leak into the local state of a later component (perf(handler): stop native attributes leaking into component state #469 by @mohamedmansour). - Templates-and-state-only SSR bootstrap payloads no longer require component style metadata (fix: allow SSR bootstrap without component styles #475 by @mohamedmansour). - The high-level Rust `serve_request` path now preserves complete render options, including CSP nonces, while sharing the same entry and request path with partial rendering (fix: forward CSP nonces through serve_request #488 by @mohamedmansour). - Projection compilation bounds source reads, excludes binary and unsupported-loader inputs from semantic analysis, and preserves deterministic cleanup under large esbuild graphs (fix: bound projection adapter source reads #489 by @mohamedmansour). - Router pending UI remains mounted through pre-commit work and settles at the synchronous DOM commit, with stale, aborted, and re-entrant navigation cleanup kept generation-safe (fix: settle router pending UI during navigation commits #491 by @mohamedmansour). Docs: - The documentation site adds accessible responsive navigation, improved reading layouts, stronger search behavior, and Playground recovery states (feat: polish WebUI documentation experience #459 by @mohamedmansour). - Slot-resolution implementation guidance now documents pre-order lookup, pending placement ownership, and marker handling (chore: clarify slot resolution comments #471 by @mohamedmansour). - Repeated `w-ref` behavior is now explicit: refs are scalar and the last wired occurrence wins, while stable authored IDs or item components provide identity-based lookup (chore: clarify repeated w-ref behavior #490 by @mohamedmansour). Maintenance: - Release and package policy metadata now constrains the transitive h2 advisory, uses SPDX NuGet licensing, and classifies publishing jobs correctly (chore: allow constrained h2 advisory #451 by @janechu, fix: use modern NuGet license metadata #457 by @janechu, chore: mark publishing jobs as release jobs #458 by @janechu). - The development and CI Rust toolchain is updated to 1.98 with the resulting warnings resolved (Update rust toolchain version and fix clippy warning #462 by @telecos). - Release builds use Thin LTO to retain cross-crate optimization with faster linking (perf: switch release builds to Thin LTO #464 by @mohamedmansour). - Handler and expression hot paths reduce attribute vtable calls, render lookup and scope allocations, and single-term condition overhead (perf(handler): centralize HTML attribute writing in ResponseWriter #467 by @mohamedmansour, perf(expressions): fast-path single-term conditions #470 by @mohamedmansour, perf(handler): reduce render lookup and scope allocations #472 by @mohamedmansour). - Node rendering can reuse immutable prepared-state snapshots and bounded per-route output capacity hints (perf(node): reuse prepared state across renders #477 by @mohamedmansour, perf: reuse Node render output capacity #478 by @mohamedmansour). - Framework hydration releases bootstrap data sooner and reduces allocations for bindings, empty hosts, and visible conditionals (perf: reduce framework hydration allocations #479 by @mohamedmansour, perf: release SSR bootstrap memory after hydration #480 by @mohamedmansour, perf: reduce empty template host overhead #482 by @mohamedmansour, perf: remove visible conditional anchors #483 by @mohamedmansour). - Benchmark tooling now renders the full contact workload, runs Criterion baselines per target, and restores the streaming hydration fixture (fix(bench): render contacts in contact-book benchmark #468 by @mohamedmansour, fix(xtask): run Criterion benchmarks per target #473 by @mohamedmansour, fix: repair streaming hydration benchmark fixture #476 by @mohamedmansour). ## Validation - `cargo xtask check` --------- Co-authored-by: Copilot App <223556219+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
2 participants
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.
Summary
#webui-datastartup blocks to omitcomponentStylescomponentStylesvalues when the field is presentValidation
[WebUI] componentStyles is required.with the pre-fix loaderpnpm --dir packages/webui-framework test:unitpnpm --dir packages/webui-framework typecheck:e2epnpm --dir packages/webui-framework exec playwright test lazy-hydration.spec.ts light-shadow-policy.spec.ts(37 passed)WEBUI_LAZY_HYDRATION_RUNS=1 WEBUI_LAZY_HYDRATION_TRACE_RUNS=0 pnpm --dir examples/integration/streaming-browser-bench test:lazy-hydration(1 passed)cargo xtask check