Add @taffyjs/yoga compatibility package

[hyfdev]

Summary

• record the accepted @taffyjs/yoga compatibility decisions and the Yoga 3.2.1 API/behavior reference
• define the TypeScript-over-@taffyjs/node runtime architecture, repository changes, six implementation milestones, and verification gates
• add the PCR-required unattended-run goal and status files so later implementation can proceed milestone by milestone on this draft PR

Why

The implementation needs a stable boundary before the compatibility facade is built: no Taffy/core or @taffyjs/node changes, no JavaScript Flex implementation, explicit Compatible/Different/Unsupported behavior, and one reviewed observable commit per milestone. The plan also accounts for Vite+ multi-entry shared chunks, pre-commit versus post-commit failure ownership, and the package-manager alias that preserves existing yoga-layout imports.

This PR is intentionally a draft. Milestone 0 contains documentation only. The unattended implementation must not start until Yunfei vouches the exact .agents/docs/loop-goal.md; Milestones 1–6 will then be committed and pushed here after their individual adversarial reviews.

Checks

• vp run check:format
• local Markdown link resolution check
• git diff --check
• independent adversarial review plus one targeted follow-up; all material findings were incorporated and the final untracked-output freshness correction was verified against the repository's existing intent-to-add pattern

[Copilot]

Pull request overview

Adds a new Yoga 3.2.1 compatibility layer to the monorepo (@taffyjs/yoga) implemented in TypeScript over @taffyjs/node, along with a dedicated integration-test workspace and supporting CI/task-graph/docs updates.

Changes:

• Introduce packages/taffyjs-yoga (ESM-only Yoga facade, translation/projection/measurement logic, compatibility docs) and commit its dist/ outputs.
• Add tests/taffyjs-yoga workspace with differential/oracle tests plus a d.ts public-API surface check.
• Wire new build/test tasks into the root Vite+ task graph and update CI/docs (PCR decisions, architecture, tooling notes).

Reviewed changes

Copilot reviewed 39 out of 47 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
vite.config.ts	Adds yoga build + test tasks and ignores yoga dist for fmt/lint.
tests/taffyjs-yoga/vite.config.ts	Vite+ config for yoga integration test workspace.
tests/taffyjs-yoga/tsconfig.json	TypeScript config for yoga integration tests.
tests/taffyjs-yoga/package.json	Defines yoga integration test workspace (name/scripts/deps).
tests/taffyjs-yoga/layout.test.mts	Basic layout parity smoke test vs oracle.
tests/taffyjs-yoga/config.test.mts	Config API/state and rejection behavior tests.
tests/taffyjs-yoga/exports.test.mts	Export surface parity tests vs oracle (enums/constants/types).
tests/taffyjs-yoga/topology.test.mts	Topology/ownership/mutation/lifetime tests.
tests/taffyjs-yoga/style.test.mts	Style getter/setter roundtrip + normalization tests vs oracle.
tests/taffyjs-yoga/state.test.mts	Dirty/new-layout/public-state transition tests.
tests/taffyjs-yoga/measurement.test.mts	Measure callback mapping/normalization/retry behavior tests.
tests/taffyjs-yoga/lifecycle.test.mts	free/freeRecursive/reset/destroy behavior tests.
tests/taffyjs-yoga/differences.test.mts	Regression fixtures for documented “Different” behaviors.
tests/taffyjs-yoga/fixtures/measure-path-profile.mjs	Fixture to assert which native compute path was taken.
tests/taffyjs-yoga/types/tsconfig.json	Typecheck-only config for d.ts surface assertions.
tests/taffyjs-yoga/types/public-api.test-d.ts	Type-level assertions for public API compatibility constraints.
pnpm-lock.yaml	Adds lock entries for new yoga package + tests workspace deps.
packages/taffyjs-yoga/package.json	New @taffyjs/yoga package metadata + exports/engines/scripts.
packages/taffyjs-yoga/README.md	Usage and compatibility/migration guidance for the facade.
packages/taffyjs-yoga/COMPATIBILITY.md	Declares Compatible/Different/Unsupported boundaries + WIP notes.
packages/taffyjs-yoga/THIRD_PARTY_NOTICES.md	Third-party notice for ported PixelGrid logic.
packages/taffyjs-yoga/vite.config.ts	Vite+ pack config for yoga (multi-entry, dts, clean dist).
packages/taffyjs-yoga/tsconfig.json	TypeScript config for yoga package source.
packages/taffyjs-yoga/src/index.ts	Root entry: eager default facade + re-exports.
packages/taffyjs-yoga/src/load.ts	/load entry: async factory + re-exports.
packages/taffyjs-yoga/src/enums.ts	Yoga-shaped enums + legacy constant map.
packages/taffyjs-yoga/src/types.ts	Public TS surface types (Node/Config/Value/etc).
packages/taffyjs-yoga/src/declarations.ts	Internal declaration storage + edge/gutter resolution helpers.
packages/taffyjs-yoga/src/values.ts	Value normalization, conversion to @taffyjs/node inputs.
packages/taffyjs-yoga/src/translate.ts	Style translation and calculation-time overrides mapping to Taffy.
packages/taffyjs-yoga/src/projection.ts	Projects Taffy output into Yoga-shaped computed output + rounding.
packages/taffyjs-yoga/src/measurement.ts	Bridges Taffy measurement calls into Yoga measure callback semantics.
packages/taffyjs-yoga/dist/index.js	Committed built JS for root entry.
packages/taffyjs-yoga/dist/index.d.ts	Committed built typings for root entry.
packages/taffyjs-yoga/dist/load.js	Committed built JS for /load entry.
packages/taffyjs-yoga/dist/load.d.ts	Committed built typings for /load entry.
packages/taffyjs-yoga/dist/types-CQnSOAjF.d.ts	Committed rolled-up type chunk from the build.
.github/workflows/ci.yml	Extends “committed outputs freshness” check to include yoga dist.
.agents/docs/README.md	Adds index links for yoga decisions + reference docs.
.agents/docs/taffyjs-yoga-decisions.md	New PCR decision ledger for yoga compatibility.
.agents/docs/technology-stack.md	Documents yoga’s build/output handling and CI freshness approach.
.agents/docs/architecture.md	Updates architecture to include yoga package + tests workspace.
.agents/docs/intent.md	Updates intent to reflect yoga as an actual package (not hypothetical).

Files not reviewed (1)

• pnpm-lock.yaml: Generated file

---

💡 Add a code-review agent skill or configure MCP servers for context-aware, tailored reviews. Learn more in the docs.