feat(parser): add JSON-LD schema.org/Recipe extractor

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

src/lib/server/parsers/json-ld-recipe.ts

@@ -0,0 +1,159 @@
+import { parseHTML } from 'linkedom';
+import { parseIso8601Duration } from './iso8601-duration';
+import { parseIngredient } from './ingredient';
+import type { Recipe, Step } from '$lib/types';
+
+type JsonLdNode = Record<string, unknown>;
+
+function unwrapGraph(node: unknown): JsonLdNode[] {
+  if (Array.isArray(node)) return node.flatMap(unwrapGraph);
+  if (node && typeof node === 'object') {
+    const obj = node as JsonLdNode;
+    if (obj['@graph']) return unwrapGraph(obj['@graph']);
+    return [obj];
+  }
+  return [];
+}
+
+function isRecipeType(t: unknown): boolean {
+  if (typeof t === 'string') return t === 'Recipe' || t.endsWith('/Recipe');
+  if (Array.isArray(t)) return t.some(isRecipeType);
+  return false;
+}
+
+function toText(v: unknown): string | null {
+  if (typeof v === 'string') return v.trim() || null;
+  if (Array.isArray(v) && v.length > 0) return toText(v[0]);
+  if (v && typeof v === 'object') {
+    const o = v as JsonLdNode;
+    if (typeof o.name === 'string') return o.name.trim();
+    if (typeof o.text === 'string') return o.text.trim();
+  }
+  return null;
+}
+
+function toImageUrl(v: unknown): string | null {
+  if (typeof v === 'string') return v;
+  if (Array.isArray(v) && v.length > 0) return toImageUrl(v[0]);
+  if (v && typeof v === 'object') {
+    const o = v as JsonLdNode;
+    if (typeof o.url === 'string') return o.url;
+  }
+  return null;
+}
+
+function toStringArray(v: unknown): string[] {
+  if (Array.isArray(v)) return v.map((x) => toText(x)).filter((x): x is string => x !== null);
+  if (typeof v === 'string') return v.split(',').map((s) => s.trim()).filter(Boolean);
+  return [];
+}
+
+function toSteps(v: unknown): Step[] {
+  const out: Step[] = [];
+  const walk = (x: unknown): void => {
+    if (Array.isArray(x)) {
+      for (const item of x) walk(item);
+      return;
+    }
+    if (typeof x === 'string') {
+      if (x.trim()) out.push({ position: out.length + 1, text: x.trim() });
+      return;
+    }
+    if (x && typeof x === 'object') {
+      const obj = x as JsonLdNode;
+      if (obj['@type'] === 'HowToSection' && obj.itemListElement) {
+        walk(obj.itemListElement);
+        return;
+      }
+      if (obj['@type'] === 'HowToStep' && typeof obj.text === 'string') {
+        if (obj.text.trim()) out.push({ position: out.length + 1, text: obj.text.trim() });
+        return;
+      }
+      if (typeof obj.text === 'string' && obj.text.trim()) {
+        out.push({ position: out.length + 1, text: obj.text.trim() });
+      }
+    }
+  };
+  walk(v);
+  return out;
+}
+
+function toServings(v: unknown): number | null {
+  if (typeof v === 'number' && Number.isFinite(v)) return Math.trunc(v);
+  if (typeof v === 'string') {
+    const m = /(\d+)/.exec(v);
+    if (m) return parseInt(m[1], 10);
+  }
+  if (Array.isArray(v) && v.length > 0) return toServings(v[0]);
+  return null;
+}
+
+function findRecipeNode(html: string): JsonLdNode | null {
+  const { document } = parseHTML(html);
+  const scripts = document.querySelectorAll('script[type="application/ld+json"]');
+  for (const script of scripts) {
+    const raw = script.textContent;
+    if (!raw) continue;
+    try {
+      const parsed = JSON.parse(raw);
+      for (const node of unwrapGraph(parsed)) {
+        if (isRecipeType(node['@type'])) return node;
+      }
+    } catch {
+      // malformed JSON-LD, keep scanning
+    }
+  }
+  return null;
+}
+
+export function extractRecipeFromHtml(html: string): Recipe | null {
+  const node = findRecipeNode(html);
+  if (!node) return null;
+
+  const title = toText(node.name) ?? '';
+  if (!title) return null;
+
+  const ingredients = Array.isArray(node.recipeIngredient)
+    ? (node.recipeIngredient as unknown[])
+        .map((x, i) => (typeof x === 'string' ? parseIngredient(x, i + 1) : null))
+        .filter((x): x is NonNullable<typeof x> => x !== null)
+    : [];
+
+  const steps = toSteps(node.recipeInstructions);
+  const imageUrl = toImageUrl(node.image);
+
+  const prep = parseIso8601Duration(
+    typeof node.prepTime === 'string' ? node.prepTime : undefined
+  );
+  const cook = parseIso8601Duration(
+    typeof node.cookTime === 'string' ? node.cookTime : undefined
+  );
+  const total = parseIso8601Duration(
+    typeof node.totalTime === 'string' ? node.totalTime : undefined
+  );
+
+  const tags = new Set<string>([
+    ...toStringArray(node.recipeCategory),
+    ...toStringArray(node.recipeCuisine),
+    ...toStringArray(node.keywords)
+  ]);
+
+  return {
+    id: null,
+    title,
+    description: toText(node.description),
+    source_url: typeof node.url === 'string' ? node.url : null,
+    source_domain: null,
+    image_path: imageUrl,
+    servings_default: toServings(node.recipeYield),
+    servings_unit: null,
+    prep_time_min: prep,
+    cook_time_min: cook,
+    total_time_min: total,
+    cuisine: toText(node.recipeCuisine),
+    category: toText(node.recipeCategory),
+    ingredients,
+    steps,
+    tags: [...tags]
+  };
+}

tests/unit/json-ld-recipe.test.ts

@@ -0,0 +1,44 @@
+import { describe, it, expect } from 'vitest';
+import { readFileSync } from 'node:fs';
+import { dirname, join } from 'node:path';
+import { fileURLToPath } from 'node:url';
+import { extractRecipeFromHtml } from '../../src/lib/server/parsers/json-ld-recipe';
+
+const here = dirname(fileURLToPath(import.meta.url));
+
+function load(name: string): string {
+  return readFileSync(join(here, '../fixtures', name), 'utf8');
+}
+
+describe('extractRecipeFromHtml', () => {
+  it('extracts a recipe from Chefkoch HTML', () => {
+    const html = load('chefkoch-schupfnudeln.html');
+    const r = extractRecipeFromHtml(html);
+    expect(r).not.toBeNull();
+    expect(r!.title.toLowerCase()).toContain('schupfnudel');
+    expect(r!.ingredients.length).toBeGreaterThan(2);
+    expect(r!.steps.length).toBeGreaterThan(0);
+  });
+
+  it('extracts a recipe from Emmi kocht einfach HTML', () => {
+    const html = load('emmi-bolognese.html');
+    const r = extractRecipeFromHtml(html);
+    expect(r).not.toBeNull();
+    expect(r!.title.toLowerCase()).toContain('bolognese');
+    expect(r!.ingredients.length).toBeGreaterThan(0);
+    expect(r!.steps.length).toBeGreaterThan(0);
+  });
+
+  it('returns null when no Recipe JSON-LD present', () => {
+    const html = '<html><body><p>no recipe</p></body></html>';
+    expect(extractRecipeFromHtml(html)).toBeNull();
+  });
+
+  it('returns null when JSON-LD has only non-Recipe types', () => {
+    const html = `
+      <html><head>
+      <script type="application/ld+json">{"@context":"https://schema.org","@type":"Organization","name":"Foo"}</script>
+      </head></html>`;
+    expect(extractRecipeFromHtml(html)).toBeNull();
+  });
+});