Adding JSON marshalling

cmd/api/handlers.go

@@ -31,7 +31,31 @@ func (app *application) getMovieHandler(w http.ResponseWriter, r *http.Request)
 }
 
 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)
+	// JSON has to be double quoted. FYI you would never really do this
+	// js := `{"status": "available", "environment": %q, "version": %q}`
+	// js = fmt.Sprintf(js, app.config.env, Version)
+	// w.Write([]byte(js))
+	data := map[string]string{
+		"status":      "available",
+		"environment": app.config.env,
+		"version":     Version,
+	}
+
+	// js, err := json.Marshal(data)
+	// if err != nil {
+	// 	app.logger.Error(err.Error())
+	// 	http.Error(w, "The server encountered a problem and could not process your request", http.StatusInternalServerError)
+	// 	return
+	// }
+	// // Append a newline to the JSON. This is just a small nicety to make it easier to
+	// // view in terminal applications.
+	// js = append(js, '\n')
+	// w.Header().Set("Content-Type", "application/json")
+	// w.Write(js)
+	err := app.writeJSON(w, 200, data, nil)
+	if err != nil {
+		app.logger.Error(err.Error())
+		http.Error(w, "The server encountered a problem and could not process your request", http.StatusInternalServerError)
+		return
+	}
 }

cmd/api/handlers_test.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"bytes"
+	"encoding/json"
 	"fmt"
 	"io"
 	"log/slog"
@@ -36,12 +37,12 @@ func TestHealthRoute(t *testing.T) {
 	}
 	defer resp.Body.Close()
 	body, err := io.ReadAll(resp.Body)
-
 	assert.NilError(t, err)
+	jsonContent := make(map[string]string)
 
-	body = bytes.TrimSpace(body)
+	json.Unmarshal(body, &jsonContent)
 
-	assert.StringContains(t, string(body), "environment: test")
+	assert.Equal(t, jsonContent["environment"], "test")
 }
 
 func TestCreateMovieHandler(t *testing.T) {

cmd/api/helpers.go

@@ -0,0 +1,33 @@
+package main
+
+import (
+	"encoding/json"
+	"net/http"
+)
+
+func (app *application) writeJSON(w http.ResponseWriter, status int, data any, headers http.Header) error {
+
+	js, err := json.Marshal(data)
+	if err != nil {
+		return err
+	}
+
+	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
+	}
+
+	// Add 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
+}