feat(parser): add ingredient parser

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/lib/server/parsers/ingredient.ts

@@ -0,0 +1,68 @@
+import type { Ingredient } from '$lib/types';
+
+const UNITS = new Set([
+  'g',
+  'kg',
+  'ml',
+  'l',
+  'cl',
+  'dl',
+  'TL',
+  'EL',
+  'Prise',
+  'Pck.',
+  'Pkg',
+  'Becher',
+  'Stk',
+  'Stück',
+  'Bund',
+  'Tasse',
+  'Dose'
+]);
+
+const FRACTION_MAP: Record<string, number> = {
+  '1/2': 0.5,
+  '1/3': 1 / 3,
+  '2/3': 2 / 3,
+  '1/4': 0.25,
+  '3/4': 0.75
+};
+
+function parseQuantity(raw: string): number | null {
+  const trimmed = raw.trim();
+  if (FRACTION_MAP[trimmed] !== undefined) return FRACTION_MAP[trimmed];
+  const rangeMatch = /^(\d+[.,]?\d*)\s*[-–]\s*\d+[.,]?\d*$/.exec(trimmed);
+  if (rangeMatch) {
+    return parseFloat(rangeMatch[1].replace(',', '.'));
+  }
+  const num = parseFloat(trimmed.replace(',', '.'));
+  return Number.isFinite(num) ? num : null;
+}
+
+export function parseIngredient(raw: string, position = 0): Ingredient {
+  const rawText = raw.trim();
+  let working = rawText;
+  let note: string | null = null;
+  const noteMatch = /\(([^)]+)\)/.exec(working);
+  if (noteMatch) {
+    note = noteMatch[1].trim();
+    working = (
+      working.slice(0, noteMatch.index) + working.slice(noteMatch.index + noteMatch[0].length)
+    ).trim();
+  }
+
+  const qtyPattern = /^((?:\d+[.,]?\d*(?:\s*[-–]\s*\d+[.,]?\d*)?)|(?:\d+\/\d+))\s+(.+)$/;
+  const qtyMatch = qtyPattern.exec(working);
+  if (!qtyMatch) {
+    return { position, quantity: null, unit: null, name: working, note, raw_text: rawText };
+  }
+  const quantity = parseQuantity(qtyMatch[1]);
+  let rest = qtyMatch[2].trim();
+  let unit: string | null = null;
+  const firstTokenMatch = /^(\S+)\s+(.+)$/.exec(rest);
+  if (firstTokenMatch && UNITS.has(firstTokenMatch[1])) {
+    unit = firstTokenMatch[1];
+    rest = firstTokenMatch[2].trim();
+  }
+  return { position, quantity, unit, name: rest, note, raw_text: rawText };
+}

tests/unit/ingredient.test.ts

@@ -0,0 +1,42 @@
+import { describe, it, expect } from 'vitest';
+import { parseIngredient } from '../../src/lib/server/parsers/ingredient';
+
+describe('parseIngredient', () => {
+  it.each([
+    ['200 g Mehl', { quantity: 200, unit: 'g', name: 'Mehl' }],
+    ['1 kg Kartoffeln', { quantity: 1, unit: 'kg', name: 'Kartoffeln' }],
+    ['500 ml Milch', { quantity: 500, unit: 'ml', name: 'Milch' }],
+    ['1 TL Salz', { quantity: 1, unit: 'TL', name: 'Salz' }],
+    ['2 EL Olivenöl', { quantity: 2, unit: 'EL', name: 'Olivenöl' }],
+    ['3 Eier', { quantity: 3, unit: null, name: 'Eier' }],
+    ['1/2 Zitrone', { quantity: 0.5, unit: null, name: 'Zitrone' }],
+    ['1,5 l Wasser', { quantity: 1.5, unit: 'l', name: 'Wasser' }]
+  ] as const)('parses %s', (input, expected) => {
+    const parsed = parseIngredient(input);
+    expect(parsed.quantity).toBe(expected.quantity);
+    expect(parsed.unit).toBe(expected.unit);
+    expect(parsed.name).toBe(expected.name);
+    expect(parsed.raw_text).toBe(input);
+  });
+
+  it('handles notes', () => {
+    const p = parseIngredient('200 g Mehl (Type 550)');
+    expect(p.quantity).toBe(200);
+    expect(p.name).toBe('Mehl');
+    expect(p.note).toBe('Type 550');
+  });
+
+  it('falls back to raw_text when unparsable', () => {
+    const p = parseIngredient('etwas frischer Pfeffer');
+    expect(p.quantity).toBeNull();
+    expect(p.unit).toBeNull();
+    expect(p.name).toBe('etwas frischer Pfeffer');
+    expect(p.raw_text).toBe('etwas frischer Pfeffer');
+  });
+
+  it('handles ranges by taking the lower bound', () => {
+    const p = parseIngredient('2-3 Tomaten');
+    expect(p.quantity).toBe(2);
+    expect(p.name).toBe('Tomaten');
+  });
+});