Updating healthcheckHandler with JSON response.

cmd/api/healthcheck.go

@@ -5,10 +5,6 @@ import (
 	"net/http"
 )
 
-/*
-Declare a handler which writes a plain-text response with information about the
-application status, operating environment and version
-*/
 /*
 Tips: The important thing to point out here is that healthcheckHandler is implemented as a method
 on our application struct. This is an effective and idiomatic way to make dependencies available
@@ -17,7 +13,22 @@ healthcheckHandler needs can simply be included as a field in the application st
 initialize it in main()
 */
 func (app *application) healthcheckHandler(w http.ResponseWriter, r *http.Request) {
-	fmt.Fprintln(w, "status: available")
-	fmt.Fprintf(w, "environment: %s\n", app.config.env)
-	fmt.Fprintf(w, "version: %s\n", version)
+	/*
+		Create a fixed-format JSON response from a string. Notice how we're using a raw
+		string literal (enclosed with backticks) so that we can include double-quote
+		characters in the JSON without needing to espace them? We also use the %q verb to
+		wrap the interpolated values in double-quotes.
+	*/
+	js := `{"status": "available", "environment": %q, "version": %q}`
+	js = fmt.Sprintf(js, app.config.env, version)
+
+	/*
+		Set the "Content-Type: application/json" header on the response. If you forget to
+		this, Go will default to sending a "Content-Type: text/plain; charset=utf-8"
+		header instead.
+	*/
+	w.Header().Set("Content-Type", "application/json")
+
+	// Write the JSON as the HTTP response body.
+	w.Write([]byte(js))
 }