block3.go

func constructQuery(q string, size int) *strings.Reader {

	// Build a query string from string passed to function
	var query = `{"query": {`

	// Concatenate query string with string passed to method call
	query = query + q

	// Use the strconv.Itoa() method to convert int to string
	query = query + `}, "size": ` + strconv.Itoa(size) + `}`
	fmt.Println("\nquery:", query)

	// Check for JSON errors
	isValid := json.Valid([]byte(query)) // returns bool

	// Default query is "{}" if JSON is invalid
	if isValid == false {
		fmt.Println("constructQuery() ERROR: query string not valid:", query)
		fmt.Println("Using default match_all query")
		query = "{}"
	} else {
		fmt.Println("constructQuery() valid JSON:", isValid)
	}

	// Build a new string from JSON query
	var b strings.Builder
	b.WriteString(query)

	// Instantiate a *strings.Reader object from string
	read := strings.NewReader(b.String())

	// Return a *strings.Reader object
	return read
}