Google Structured Data Testing Tool giving error: "Missing '}' or object member name."

Question

I write some code of JSON-LD, but Google’s SDTT is showing an error.

Following is the code.

{
    "@context": "https://schema.org/",
    "@type": "Review",
    "reviewBody": "\"Singapore's top rated maid search portal\" - Business Times",
    "url":"https://web.facebook.com/pg/SearchMaid/reviews/",
    "author": {
        "@type": "Person",
        "name": "Business Times"
    },
    "itemReviewed": {
        "@type": "ProfessionalService",
        "name": "SearchMaid",
        "image":"https://searchmaid.com.sg/assets/dlogo-3dabd5569068236053204ac4881a7f9f4ee72ecd7950275a15ab753c793ead5d.png",
        "telephone":"+6587551411",
        "priceRange":"S$500 - S$700",
        "address": {
        "@type": "PostalAddress",
            "name":"140 Paya Lebar Road, A-Z Building #09-22, Singapore 409015"
        }
    },
    "publisher": {
        "@type": "Organization",
        "name": "SearchMaid"
    },
    "reviewRating": {
        "@type": "Rating",
        "description": "",
        "ratingValue": "5"
    },
    "isBasedOn": {
        "@type": "Product",
        {
            "@type": "AggregateRating",
            "reviewCount": "3"
        }
    }
}

At what place I am doing something wrong?

Answer 1

The problem seems to be at isBasedOn > Product > data. Check the isBasedOn documentation and validate with this tool. If you delete the last part, the code is valid.

{
    "@context": "https://schema.org/",
    "@type": "Review",
    "reviewBody": "\"Singapore's top rated maid search portal\" - Business Times",
    "url":"https://web.facebook.com/pg/SearchMaid/reviews/",
    "author": {
        "@type": "Person",
        "name": "Business Times"
    },
    "itemReviewed": {
        "@type": "ProfessionalService",
        "name": "SearchMaid",
        "image":"https://searchmaid.com.sg/assets/dlogo-3dabd5569068236053204ac4881a7f9f4ee72ecd7950275a15ab753c793ead5d.png",
        "telephone":"+6587551411",
        "priceRange":"S$500 - S$700",
        "address": {
        "@type": "PostalAddress",
            "name":"140 Paya Lebar Road, A-Z Building #09-22, Singapore 409015"
        }
    },
    "publisher": {
        "@type": "Organization",
        "name": "SearchMaid"
    },
    "reviewRating": {
        "@type": "Rating",
        "description": "",
        "ratingValue": "5"
    },
    "isBasedOn": {
        "@type": "Product"
    }
}