feat(mix_tailwinds): verified Tailwind parity with functional API and web showcase (#1009)

Author: leoafarias

.github/workflows/test.yml

@@ -49,3 +49,23 @@ jobs:
       melos-commands: |
         melos run schema:inventory
         melos run analyze:dart
+
+  showcase-tool:
+    name: Showcase Tool Tests
+    runs-on: ubuntu-latest
+    defaults:
+      run:
+        working-directory: packages/mix_tailwinds/tool/visual-comparison
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
+        with:
+          node-version: 22
+          cache: npm
+          cache-dependency-path: packages/mix_tailwinds/tool/visual-comparison/package-lock.json
+      - name: Install Node dependencies
+        run: npm ci
+      - name: Install Chromium
+        run: npx playwright install --with-deps chromium
+      - name: Run showcase tool tests
+        run: npm test

.gitignore

@@ -5,6 +5,7 @@
 *.pyc
 *.swp
 .DS_Store
+.context/
 .atom/
 .buildlog/
 .history
@@ -131,3 +132,9 @@ website/public/previews/
 # Playwright
 website/playwright-report/
 website/test-results/
+
+# The mix_tailwinds example has a hand-authored web showcase. Keep its source
+# in version control while excluding parity evidence generated during builds.
+!packages/mix_tailwinds/example/web/
+!packages/mix_tailwinds/example/web/**
+packages/mix_tailwinds/example/web/generated/

melos.yaml

@@ -29,6 +29,7 @@ categories:
     - packages/mix
     - packages/mix_protocol
     - packages/mix_tailwinds
+    - packages/mix_tailwinds/example
     - packages/mix_chart
     - packages/mix_chart/example
     - packages/mix/example

packages/mix_tailwinds/ADAPTATION_PARITY_REPORT.md

@@ -1,12 +1,58 @@
 ## Unreleased
 
+- Fixed `self-start`, `self-end`, and `self-center`, which silently did nothing
+  whenever the container carried an `items-*` utility. A flex holding a
+  self-aligned child now renders through a `RenderFlex` that offsets those
+  children after it has measured its cross axis, so the override also works in
+  the common case of a row nested inside a column.
+- **Breaking:** `TwConfig.standard()` now contains only Tailwind CSS 4.3.1
+  defaults. The fixture-only `brand-500`, `card` spacing/radius, `3xl`
+  breakpoint, and `shadow-card` values were removed; add project values with
+  `TwConfig.copyWith` or explicit Mix composition.
+- **Breaking (experimental alpha):** Removed `TwPressable` in favor of `Button`;
+  rename `onPress` to `onPressed`. A null `onPressed` disables the control
+  unless `onLongPress` supplies an action, and semantics are always button
+  semantics. Its margin stays outside the pressed, tappable, and semantic
+  border box.
+- Added class-first lowercase convenience functions for `Div`, text, headings,
+  `Button`, `TwIcon`, and `TruncatedP`. They return the concrete uppercase
+  widgets; use those const-capable constructors for advanced options.
+- `H1` through `H6` now expose matching Flutter semantics heading levels 1
+  through 6.
+- Generated every supported default theme namespace from a checked-in,
+  versioned Tailwind 4.3.1 snapshot, including the complete stock palette and
+  corrected radii, blurs, font line heights, leading, and tracking values.
+- Resolve `tracking-*` em values against the final font size and preserve an
+  explicit `leading-*` over font-size defaults in either class order, including
+  inherited default text styles.
+- Fixed nested interaction variants, routed `focus-visible` through input
+  modality, and removed the non-Tailwind `theme-midnight` dark-mode alias.
+- Fixed fixed/fraction/full/auto responsive width behavior under stretched
+  Flutter constraints. Responsive `w-auto` and `h-auto` now clear earlier
+  fixed constraints explicitly.
+- Visual comparisons now enforce per-example, per-width acceptance contracts
+  and generate a filterable, browser-smoked HTML light-table report after
+  successful and failed runs.
+- Added a source-backed web showcase for five product-scale examples with
+  Tailwind/Flutter code comparison, published parity evidence, linkable
+  viewports, and one-engine single/multi-view Flutter embedding modes. Showcase
+  builds reject incomplete, malformed, or stale parity evidence by validating
+  the canonical viewport set and a content fingerprint of their source inputs.
 - **Breaking (experimental alpha):** Removed the legacy `TwResolver`, the
   `wrapDefaultTextStyle` styler extensions, and unused `TwConfig` lookup
   helpers. Use `TwParser`, standard Mix composition, and the public config
   maps instead.
+- **Breaking (experimental alpha):** Removed the unused semantic AST and plugin
+  registry that were previously exported from `tw_semantic.dart`.
 - Restored the hosted `mix: ^2.1.0` dependency so the package remains
   publishable by the repository release workflow.
-- Report unsupported `basis-*` flex item utilities through `onUnsupported`
+- Added structured `TwDiagnostic` reporting through `onDiagnostic`; ignored
+  adaptations and unsupported candidates no longer disappear silently. The
+  token-only `onUnsupported` callback remains as a deprecated shim.
+- Resolve conflicting utilities in canonical registry order across translated
+  styles and constraint-aware widget behavior, so class-string order no longer
+  changes base, variant, flex-axis, gap, or self-alignment output.
+- Report unsupported `basis-*` flex item utilities through `onDiagnostic`
   instead of silently ignoring fraction, full, arbitrary, or unknown values.
 - Keep supported `basis-auto` and spacing-scale basis utilities quiet while
   preserving the existing pixel-basis runtime behavior.