Create a method that fetches product reviews from the DummyJSON API and returns formatted review information.

Your method should:

• Make an HTTP GET request to https://dummyjson.com/products/{productId}
• Parse the JSON response to extract the reviews array
• Format each review as: "{reviewerName}: {rating}/5 - {comment}"
• Return a List of Strings containing all formatted reviews
• Return an empty list if the product has no reviews
• Return null if productId is null or less than 1

API Response Structure

The DummyJSON API returns a product object with a reviews array:

{
  "id": 1,
  "title": "Product Name",
  "reviews": [
    {
      "rating": 4,
      "comment": "Great product!",
      "reviewerName": "John Doe",
      "reviewerEmail": "john@example.com"
    }
  ]
}

Examples

Example 1: Valid Product with Reviews

• Input: productId = 1
• Output: ["Emily Johnson: 2/5 - Very unhappy with my purchase!", "Michael Smith: 4/5 - Very pleased!", "Sophia Brown: 5/5 - Highly impressed!"]

Example 2: Null Product ID

• Input: productId = null
• Output: null

Example 3: Invalid Product ID

• Input: productId = 0
• Output: null