ContrastNote: inline low-contrast hint with suggestion

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

craft/src/panels/right/styles/ContrastNote.test.tsx

@@ -0,0 +1,59 @@
+import { describe, test, expect, vi, afterEach } from 'vitest';
+import React from 'react';
+import { createRoot, Root } from 'react-dom/client';
+import { act } from 'react-dom/test-utils';
+import { ContrastNote } from './ContrastNote';
+import { SiteDesignProvider } from '../../../state/SiteDesignContext';
+
+let container: HTMLDivElement | null = null;
+let root: Root;
+function render(ui: React.ReactElement) {
+  container = document.createElement('div');
+  document.body.appendChild(container);
+  act(() => { root = createRoot(container!); root.render(<SiteDesignProvider>{ui}</SiteDesignProvider>); });
+}
+afterEach(() => {
+  if (!container) return;
+  act(() => { root.unmount(); });
+  container.remove();
+  container = null;
+});
+
+describe('ContrastNote', () => {
+  test('renders nothing when the pair passes', () => {
+    render(<ContrastNote fg="#000000" bg="#ffffff" />);
+    expect(container!.innerHTML).toBe('');
+  });
+
+  test('renders nothing for an unresolved colour', () => {
+    render(<ContrastNote fg="var(--nope)" bg="#ffffff" />);
+    expect(container!.innerHTML).toBe('');
+  });
+
+  test('fail shows ratio and threshold in a status region', () => {
+    render(<ContrastNote fg="#aaaaaa" bg="#ffffff" />);
+    const el = container!.querySelector('[role="status"]')!;
+    expect(el.textContent).toBe('Low contrast 2.32:1 (needs 4.5:1)');
+    expect(container!.querySelector('button')).toBeNull();
+  });
+
+  test('large text uses the 3:1 threshold; label prefixes', () => {
+    render(<ContrastNote fg="#cccccc" bg="#ffffff" large label="Heading" />);
+    expect(container!.textContent).toBe('Heading: Low contrast 1.61:1 (needs 3:1)');
+  });
+
+  test('suggestion button calls back with a passing hex', () => {
+    const cb = vi.fn();
+    render(<ContrastNote fg="#aaaaaa" bg="#ffffff" onUseSuggestion={cb} />);
+    const btn = container!.querySelector('button')!;
+    expect(btn.textContent).toMatch(/^Use #[0-9a-f]{6}$/);
+    act(() => { btn.click(); });
+    expect(cb).toHaveBeenCalledTimes(1);
+    expect(cb.mock.calls[0][0]).toMatch(/^#[0-9a-f]{6}$/);
+  });
+
+  test('gradient background shows a muted not-checked note', () => {
+    render(<ContrastNote fg="#ffffff" bg="linear-gradient(red, blue)" />);
+    expect(container!.querySelector('[role="status"]')!.textContent).toBe('Contrast not checked (gradient)');
+  });
+});

craft/src/panels/right/styles/ContrastNote.tsx

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+import React from 'react';
+import { useSiteDesign } from '../../../state/SiteDesignContext';
+import { checkContrast, suggestFix } from '../../../utils/contrast';
+
+export interface ContrastNoteProps {
+  fg: string;
+  bg: string;
+  large?: boolean;
+  label?: string;
+  onUseSuggestion?: (hex: string) => void;
+}
+
+/**
+ * Compact inline contrast hint. Silent when the pair passes or cannot be
+ * judged for a reason not worth mentioning; amber (not alarm red) on failure;
+ * muted "not checked" for gradient / image backgrounds.
+ */
+export const ContrastNote: React.FC<ContrastNoteProps> = ({ fg, bg, large, label, onUseSuggestion }) => {
+  const { design } = useSiteDesign();
+  const v = checkContrast(fg, bg, design, { large });
+
+  if (v.status === 'pass') return null;
+
+  if (v.status === 'unchecked') {
+    if (v.reason !== 'gradient' && v.reason !== 'image') return null;
+    return (
+      <div
+        className="contrast-note contrast-note--unchecked"
+        role="status"
+        style={{ fontSize: 11, lineHeight: 1.4, color: 'var(--color-text-muted, #8b8b96)' }}
+      >
+        Contrast not checked ({v.reason})
+      </div>
+    );
+  }
+
+  const fix = onUseSuggestion ? suggestFix(fg, bg, design, { large }) : null;
+  return (
+    <div
+      className="contrast-note contrast-note--fail"
+      role="status"
+      style={{ display: 'flex', flexWrap: 'wrap', alignItems: 'center', gap: 6, fontSize: 11, lineHeight: 1.4, color: 'var(--color-warning, #d97706)' }}
+    >
+      <span>
+        {label ? `${label}: ` : ''}Low contrast {v.ratio!.toFixed(2)}:1 (needs {v.required}:1)
+      </span>
+      {fix && (
+        <button
+          type="button"
+          className="contrast-note__use"
+          onClick={() => onUseSuggestion!(fix.hex)}
+          title={`Use ${fix.hex} (${fix.ratio.toFixed(1)}:1)`}
+          style={{ font: 'inherit', fontWeight: 600, color: 'inherit', background: 'none', border: '1px solid currentColor', borderRadius: 4, padding: '0 6px', cursor: 'pointer' }}
+        >
+          Use {fix.hex}
+        </button>
+      )}
+    </div>
+  );
+};