feat: added density conversion

lib/measurements/__tests__/plugin.test.js

@@ -272,9 +272,12 @@ describe('hybrid weight/volume measurements', () => {
     expect(html).toContain('data-volume-scalable=');
   });
 
-  it('does NOT add hybrid attributes for weight-to-weight alt', () => {
-    const md = '- butter 227g (8 oz)';
+  it('does NOT add manual hybrid attributes for weight-to-weight alt', () => {
+    // weight-to-weight alt doesn't produce manual hybrid volume data,
+    // but density-based auto hybrid will still kick in for known ingredients
+    const md = '- cheddar 227g (8 oz)';
     const html = render(md);
+    // "cheddar" is not in the density table, so no hybrid at all
     expect(html).not.toContain('data-hybrid');
   });
 
@@ -323,4 +326,196 @@ describe('hybrid weight/volume measurements', () => {
     expect(html).toContain('data-default="80g"');
     expect(html).toContain('data-measurement-type="weight"');
   });
+});
+
+// ─── Density Table ──────────────────────────────────────────
+
+const { matchDensity } = require('../densities');
+
+describe('matchDensity', () => {
+  it('returns density for known ingredient', () => {
+    expect(matchDensity('butter')).toBe(0.96);
+  });
+
+  it('is case-insensitive', () => {
+    expect(matchDensity('Butter')).toBe(0.96);
+    expect(matchDensity('FLOUR')).toBe(0.53);
+  });
+
+  it('returns null for unknown ingredient', () => {
+    expect(matchDensity('dragon fruit')).toBeNull();
+  });
+
+  it('matches longest keyword first (brown sugar vs sugar)', () => {
+    expect(matchDensity('brown sugar')).toBe(0.93);
+    expect(matchDensity('sugar')).toBe(0.85);
+  });
+
+  it('matches longest keyword first (olive oil vs oil)', () => {
+    expect(matchDensity('olive oil')).toBe(0.92);
+    expect(matchDensity('vegetable oil')).toBe(0.92);
+  });
+
+  it('matches ingredient within longer text', () => {
+    expect(matchDensity('unsalted butter')).toBe(0.96);
+    expect(matchDensity('all-purpose flour')).toBe(0.53);
+  });
+
+  it('returns null for empty/null input', () => {
+    expect(matchDensity('')).toBeNull();
+    expect(matchDensity(null)).toBeNull();
+  });
+});
+
+// ─── Density-Based Auto Hybrid Generation ───────────────────
+
+function getWeightAttrs(html) {
+  const matches = [];
+  const re = /data-hybrid="true"[^>]*data-weight-default="([^"]*)"[^>]*data-weight-alt="([^"]*)"(?:[^>]*data-weight-scalable="([^"]*)")?/g;
+  let m;
+  while ((m = re.exec(html)) !== null) {
+    matches.push({
+      weightDefault: decodeHtmlEntities(m[1]),
+      weightAlt: decodeHtmlEntities(m[2]),
+      weightScalable: m[3] ? JSON.parse(decodeHtmlEntities(m[3])) : null,
+    });
+  }
+  return matches;
+}
+
+describe('density-based auto hybrid: weight -> volume', () => {
+  it('auto-generates volume data for weight measurement with known ingredient', () => {
+    const md = '- butter 227g';
+    const html = render(md);
+    expect(html).toContain('data-hybrid="true"');
+    expect(html).toContain('data-volume-default=');
+    expect(html).toContain('data-volume-alt=');
+    expect(html).toContain('data-volume-scalable=');
+  });
+
+  it('generates correct volume from density (butter 227g)', () => {
+    const md = '- butter 227g';
+    const html = render(md);
+    const hybrids = getHybridAttrs(html);
+    expect(hybrids.length).toBe(1);
+    // 227g / 0.96 density = 236.46ml -> "236.5ml" metric
+    expect(hybrids[0].volumeDefault).toBe('236.5ml');
+    expect(hybrids[0].volumeScalable).toBeDefined();
+    expect(hybrids[0].volumeScalable.type).toBe('volume');
+    expect(hybrids[0].volumeScalable.base).toBeCloseTo(236.46, 0);
+  });
+
+  it('generates correct volume from density (flour 500g)', () => {
+    const md = '- all-purpose flour 500g';
+    const html = render(md);
+    const hybrids = getHybridAttrs(html);
+    expect(hybrids.length).toBe(1);
+    // 500g / 0.53 density = 943.4ml -> "943.4ml"
+    expect(hybrids[0].volumeDefault).toBe('943.4ml');
+  });
+
+  it('does not generate hybrid for unknown ingredient weight', () => {
+    const md = '- mystery powder 100g';
+    const html = render(md);
+    expect(html).not.toContain('data-hybrid');
+  });
+
+  it('handles range weight measurements with density', () => {
+    const md = '- butter 200-250g';
+    const html = render(md);
+    const hybrids = getHybridAttrs(html);
+    expect(hybrids.length).toBe(1);
+    // 200/0.96 = 208.3ml, 250/0.96 = 260.4ml
+    expect(hybrids[0].volumeDefault).toMatch(/208.*-.*260/);
+    expect(hybrids[0].volumeScalable.base).toHaveLength(2);
+  });
+});
+
+describe('density-based auto hybrid: volume -> weight', () => {
+  it('auto-generates weight data for volume measurement with known ingredient', () => {
+    const md = '- flour 2 cups';
+    const html = render(md);
+    expect(html).toContain('data-hybrid="true"');
+    expect(html).toContain('data-weight-default=');
+    expect(html).toContain('data-weight-alt=');
+    expect(html).toContain('data-weight-scalable=');
+  });
+
+  it('generates correct weight from density (flour 2 cups)', () => {
+    const md = '- flour 2 cups';
+    const html = render(md);
+    const weightAttrs = getWeightAttrs(html);
+    expect(weightAttrs.length).toBe(1);
+    // 2 cups = 2 * 236.588ml = 473.176ml, * 0.53 density = 250.8g
+    expect(weightAttrs[0].weightDefault).toBe('250.8g');
+    expect(weightAttrs[0].weightScalable).toBeDefined();
+    expect(weightAttrs[0].weightScalable.type).toBe('weight');
+    expect(weightAttrs[0].weightScalable.base).toBeCloseTo(250.78, 0);
+  });
+
+  it('generates correct weight from density (milk 1 cup)', () => {
+    const md = '- milk 1 cup';
+    const html = render(md);
+    const weightAttrs = getWeightAttrs(html);
+    expect(weightAttrs.length).toBe(1);
+    // 1 cup = 236.588ml, * 1.03 density = 243.69g
+    expect(weightAttrs[0].weightDefault).toBe('243.7g');
+  });
+
+  it('does not generate hybrid for unknown ingredient volume', () => {
+    const md = '- unicorn tears 1 cup';
+    const html = render(md);
+    expect(html).not.toContain('data-hybrid');
+  });
+
+  it('handles range volume measurements with density', () => {
+    const md = '- sugar 1-2 cups';
+    const html = render(md);
+    const weightAttrs = getWeightAttrs(html);
+    expect(weightAttrs.length).toBe(1);
+    // 1 cup = 236.588ml * 0.85 = 201.1g, 2 cups = 473.176ml * 0.85 = 402.2g
+    expect(weightAttrs[0].weightDefault).toMatch(/201.*-.*402/);
+    expect(weightAttrs[0].weightScalable.base).toHaveLength(2);
+  });
+});
+
+describe('density vs manual hybrid precedence', () => {
+  it('manual hybrid annotation takes precedence over density table', () => {
+    const md = '- unsalted butter 80g (6 tablespoons)';
+    const html = render(md);
+    const hybrids = getHybridAttrs(html);
+    expect(hybrids.length).toBe(1);
+    // Should use the manual 6 tablespoons, not density-computed value
+    expect(hybrids[0].volumeDefault).toBe('88.7ml');
+    expect(hybrids[0].volumeAlt).toBe('6 tbsp');
+  });
+
+  it('weight-to-weight alt does not trigger density hybrid (butter 227g (8 oz))', () => {
+    // "227g (8 oz)" is weight-to-weight alt, no manual hybrid volume data,
+    // but density should still auto-generate volume data
+    const md = '- butter 227g (8 oz)';
+    const html = render(md);
+    // getHybridVolumeData returns null for weight-to-weight, so density kicks in
+    expect(html).toContain('data-hybrid="true"');
+    const hybrids = getHybridAttrs(html);
+    expect(hybrids.length).toBe(1);
+  });
+});
+
+describe('density with approximate values', () => {
+  it('preserves approximate prefix in density-generated volume', () => {
+    const md = '- butter ~200g';
+    const html = render(md);
+    const hybrids = getHybridAttrs(html);
+    expect(hybrids.length).toBe(1);
+    expect(hybrids[0].volumeDefault).toMatch(/^~/);
+  });
+
+  it('preserves approximate prefix in density-generated weight', () => {
+    const md = '- flour ~2 cups';
+    const html = render(md);
+    const weightAttrs = getWeightAttrs(html);
+    expect(weightAttrs.length).toBe(1);
+    expect(weightAttrs[0].weightDefault).toMatch(/^~/);
+  });
 });