Creating writeJSON method inside helpers.go file. Using writeJSON helper inside healthcheckHandler.

cmd/api/helpers.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"encoding/json"
 	"errors"
 	"github.com/julienschmidt/httprouter"
 	"net/http"
@@ -41,3 +42,38 @@ func (app *application) readIDParam(r *http.Request) (int64, error) {
 
 	return id, nil
 }
+
+/*
+Define a writeJSON() helper for sending responses. This takes the destination
+http.ResponseWriter, the HTTP status code to send, the data to encode to JSON, and a
+header map containing any additional HTTP headers we want to include in the response.
+*/
+func (app *application) writeJSON(w http.ResponseWriter, status int, data any, headers http.Header) error {
+	// Encode the data to JSON, returning the error if there was one.
+	js, err := json.Marshal(data)
+	if err != nil {
+		return err
+	}
+
+	// Append a newline to make it easier to view in terminal applications.
+	js = append(js, '\n')
+
+	/*
+		At this point, we know that we won't encounter any more errors before writing the
+		response, so it's safe to add any headers that we want to include. We loop
+		through the header map and add each header to the http.ResponseWriter header map.
+		Note that it's OK if the provided header map is nil. Go doesn't throw an error
+		if you try to range over (or generally, read from) a nil map.
+	*/
+	for key, value := range headers {
+		w.Header()[key] = value
+	}
+
+	// And the "Content-Type: application/json" header, then write the status code and
+	// JSON response.
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(status)
+	w.Write(js)
+
+	return nil
+}