mcu-fork-sync

name	mcu-fork-sync
description	Check and port Dart-only upstream Material Color Utilities into the customized MCU fork under lib/src/mcu. Use when MCU, material_color_utilities, Cam16, Hct, DynamicScheme, or an upstream fork sync is mentioned, or when a new MCU Dart version is published.

MCU fork sync

Sync Dart only from material-color-utilities dart/ into this package’s fork at lib/src/mcu/. Do not fetch, diff, or translate java/, kotlin/, swift/, typescript/, or cpp/.

This is not a drop-in copy. Keep FSS deltas. Default: investigate and report. Port only when the user asks.

Path maps, FSS delta inventory, and style translation: reference.md.

Baseline

Read, in order:

1. Last synced comment in lib/src/mcu/material_color_utilities.dart
2. MCU notes in CHANGELOG.md
3. Pub.dev material_color_utilities changelog
4. GitHub dart/CHANGELOG.md (including Unreleased) and recent commits under dart/lib/

Optional: which MCU version Flutter currently pins. FSS may already be ahead; ColorScheme.fromSeed parity tests may still target Flutter’s pin.

GitHub dart/ can land months before pub.dev. Search the fork for the new helper or API before treating it as missing. Canonical case: MCU 0.13.1 Cam16 hue wrap via MathUtils.sanitizeDegreesDouble was already in FSS 4.0.0.

After every completed sync, update the Last-synced line (pub version + GitHub commit/date).

Collect Dart delta

In scope: dart/lib/**, dart/test/**, dart/CHANGELOG.md.

Compare those files to lib/src/mcu/ and test/mcu/. Ignore Google 80-column wrapping; this package uses page_width: 120 and package imports.

Repo-root docs only if they explain a Dart API or a Dart doc-link fix.

Classify every hunk

Class	Action
Already in the fork	Cite the local line. Do not re-apply.
Algorithm / color math	Port. Update MCU hex and FSS golden toString only if output is meant to change.
API rename / new public MCU type	Port. Check lib/flex_seed_scheme.dart exports. Expanding MCU exports needs demand and a stability review.
Docs / comments / URLs	Port into FSS voice. Do not add @Deprecated on Scheme.
Tests	Port useful Google tests into test/mcu/. Keep extra FSS tests. Never delete FSS coverage.
Conflicts with FSS deltas	Re-apply upstream around the deltas in reference.md. Do not strip them.

Formatter-only wrapping is not a port.

Sync report (required)

Stop here unless the user asked to implement:

# MCU sync report

- Fork last synced: <version / commit from material_color_utilities.dart>
- Upstream Dart: pub <version> | GitHub <commit> | Unreleased: <yes/no>
- Flutter MCU pin (optional): <version>

## Files that differ (Dart)

- `dart/lib/...` → `lib/src/mcu/...` — <class>

## Already applied

- <item and local location>

## Proposed work

- Risk: none | CHORE | CHANGE | BREAKING
- Flutter-parity tests: no change | flag/golden update
- CHANGELOG bullets: ...

Port (only after confirmation)

1. Surgical edits in lib/src/mcu/ and matching test/mcu/.
2. Translate imports to package:flex_seed_scheme/src/mcu/....
3. Keep Google Apache-2.0 headers and FSS // RydMike: / FlexSeedScheme notes.
4. Fold FSS constructor parameters and flags back in if upstream rewrote a scheme class.
5. dart format owns layout (page_width: 120).
6. Update Last-synced and CHANGELOG (CHORE for mechanical/docs; CHANGE / BREAKING if colors or public MCU API move).
7. Never replace the fork with a pub material_color_utilities dependency.

Verify:

fvm dart format lib test example
fvm dart analyze
fvm flutter test --coverage

Re-run test/mcu/** and the ColorScheme.fromSeed parity loop in FSS tests. Unexplained golden churn is a bug.

Do not

• Copy non-Dart MCU implementations
• “Simplify” scheme constructors or contrast-curve wiring
• Deprecate Scheme in this fork
• Casual-edit MCU hex goldens or large FSS toString blobs