How to handle JSON parser errors in ruby

Question

How do I avoid parsing JSON if the response body will not be in JSON, else it throws a huge exception which I would like to handle

      def execute_method(foo)
...

        response = self.class.get("/foo.php", query: query)
        JSON.parse(response.body)
      end

Answer 1

As @Anthony pointed out, use begin/rescue.

begin
  ...
  JSON.parse(response.body)
rescue JSON::ParserError
  # Handle error
end

Update

To check if a string is a valid json, you can create a method:

def valid_json?(string)
  !!JSON.parse(string)
rescue JSON::ParserError
  false
end

valid_json?("abc") #=> false
valid_json?("{}") #=> true