feat: added support for adding plurality to ingredients

lib/measurements/__tests__/plurals.test.js

@@ -0,0 +1,106 @@
+import { describe, it, expect } from 'vitest';
+
+const { matchPlural, PLURALS } = require('../plurals');
+
+describe('matchPlural', () => {
+  it('returns null for empty/null input', () => {
+    expect(matchPlural('')).toBeNull();
+    expect(matchPlural(null)).toBeNull();
+    expect(matchPlural(undefined)).toBeNull();
+  });
+
+  it('returns null for unknown nouns', () => {
+    expect(matchPlural('dragon fruit ')).toBeNull();
+    expect(matchPlural('toaster ')).toBeNull();
+  });
+
+  it('matches singular noun at end of text', () => {
+    const result = matchPlural('onion ');
+    expect(result).not.toBeNull();
+    expect(result.singular).toBe('onion');
+    expect(result.plural).toBe('onions');
+  });
+
+  it('matches plural noun at end of text', () => {
+    const result = matchPlural('eggs ');
+    expect(result).not.toBeNull();
+    expect(result.singular).toBe('egg');
+    expect(result.plural).toBe('eggs');
+  });
+
+  it('is case-insensitive', () => {
+    expect(matchPlural('Onion ')).not.toBeNull();
+    expect(matchPlural('EGGS ')).not.toBeNull();
+    expect(matchPlural('Tomatoes ')).not.toBeNull();
+  });
+
+  it('trims trailing whitespace', () => {
+    const result = matchPlural('onion   ');
+    expect(result).not.toBeNull();
+    expect(result.singular).toBe('onion');
+  });
+
+  it('respects word boundaries', () => {
+    // "megg" should not match "egg"
+    expect(matchPlural('megg ')).toBeNull();
+    // "button" should not match as containing a known noun
+    expect(matchPlural('button ')).toBeNull();
+  });
+
+  it('matches multi-word nouns (longest first)', () => {
+    const result = matchPlural('garlic clove ');
+    expect(result).not.toBeNull();
+    expect(result.singular).toBe('garlic clove');
+    expect(result.plural).toBe('garlic cloves');
+  });
+
+  it('matches "clove" when not preceded by "garlic"', () => {
+    const result = matchPlural('clove ');
+    expect(result).not.toBeNull();
+    expect(result.singular).toBe('clove');
+    expect(result.plural).toBe('cloves');
+  });
+
+  it('matches "bell pepper" before "pepper"', () => {
+    const result = matchPlural('bell pepper ');
+    expect(result).not.toBeNull();
+    expect(result.singular).toBe('bell pepper');
+    expect(result.plural).toBe('bell peppers');
+  });
+
+  it('matches "pepper" standalone', () => {
+    const result = matchPlural('pepper ');
+    expect(result).not.toBeNull();
+    expect(result.singular).toBe('pepper');
+    expect(result.plural).toBe('peppers');
+  });
+
+  it('provides correct matchStart and matchLength', () => {
+    const result = matchPlural('white onion ');
+    expect(result).not.toBeNull();
+    expect(result.matchStart).toBe(6); // "white " is 6 chars
+    expect(result.matchLength).toBe(5); // "onion" is 5 chars
+  });
+
+  it('handles text with prefix before noun', () => {
+    const result = matchPlural('- [ ] eggs ');
+    expect(result).not.toBeNull();
+    expect(result.singular).toBe('egg');
+    expect(result.plural).toBe('eggs');
+  });
+
+  it('matches egg yolk and egg white', () => {
+    expect(matchPlural('egg yolk ')).not.toBeNull();
+    expect(matchPlural('egg yolk ').singular).toBe('egg yolk');
+    expect(matchPlural('egg white ')).not.toBeNull();
+    expect(matchPlural('egg white ').singular).toBe('egg white');
+  });
+
+  it('dictionary is sorted longest-first', () => {
+    for (let i = 0; i < PLURALS.length - 1; i++) {
+      const currentLen = Math.max(PLURALS[i].singular.length, PLURALS[i].plural.length);
+      const nextLen = Math.max(PLURALS[i + 1].singular.length, PLURALS[i + 1].plural.length);
+      expect(currentLen).toBeGreaterThanOrEqual(nextLen);
+    }
+  });
+});