JSON-LD for a Product or Article Page

Add JSON-LD structured data that matches the visible page. If the page does not show a price or a rating, the JSON-LD does not invent one. PAGE Type: [PRODUCT | ARTICLE | FAQ] Visible facts: [LIST WHAT A HUMAN CAN SEE] URL and image: [FIELDS] Ratings: [REAL SOURCE | NONE] DELIVER 1) The schema.org type and the required properties we can fill from visible data. A script tag with JSON.stringify of a typed object, escaped so a name cannot break out of the script. 2) The rule: every value in the JSON-LD is on the page. A mapping comment from property to the element. 3) What we omit when unknown (aggregateRating with no reviews, a fake review, a price of zero). 4) A test that renders the page and parses the script, asserting the name and the absence of rating when we have none. 5) The validator we run before shipping (the public rich-results test) and the one error it usually throws for this type. Do not mark up content that is hidden. Do not copy a rating from a competitor.