Adds a writeJSON helper

3 files changed, 50 insertions, 4 deletions

diff --git a/cmd/api/healthcheck.go b/cmd/api/healthcheck.go
index c4f52f2..c046995 100644
--- a/cmd/api/healthcheck.go
+++ b/cmd/api/healthcheck.go
@@ -1,13 +1,23 @@
 package main
 
 import (
-	"fmt"
+	"encoding/json"
 	"net/http"
 )
 
 func (app *application) healthcheckHandler(w http.ResponseWriter, r *http.Request) {
-	js := `{"status": "available", "environment": %q, "version": %q}`
-	js = fmt.Sprintf(js, app.config.env, version)
+	data := map[string]string{
+		"status":      "available",
+		"environment": app.config.env,
+		"version":     version,
+	}
+	js, err := json.Marshal(data)
+	if err != nil {
+		app.logger.Debug("server error", "err", err)
+		http.Error(w, "The server encountered a problem and could not process your request", http.StatusInternalServerError)
+		return
+	}
+	js = append(js, '\n')
 	w.Header().Set("Content-Type", "application/json")
 	w.Write([]byte(js))
 }
diff --git a/cmd/api/helpers.go b/cmd/api/helpers.go
new file mode 100644
index 0000000..77fbf0c
--- /dev/null
+++ b/cmd/api/helpers.go
@@ -0,0 +1,36 @@
+package main
+
+import (
+	"encoding/json"
+	"net/http"
+)
+
+// writeJSON() helper for sending responses. This takes the destination http.ResponseWriter, the
+// HTTP status code to sned, 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, returing the error if there was one.
+	js, err := json.Marshal(data)
+	if err != nil {
+		return err
+	}
+
+	// Append a newline to make it easier tro view in terminal applications
+	js = append(js, '\n')
+
+	// We know now 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 okay if the provided header map is nil. Go doesn't throw an error
+	// if you wanmt to try to range over (or more generally reader 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
+}
diff --git a/cmd/api/main.go b/cmd/api/main.go
index 9d3e9bd..960d6a7 100644
--- a/cmd/api/main.go
+++ b/cmd/api/main.go
@@ -55,7 +55,7 @@ func main() {
 		ErrorLog:     slog.NewLogLogger(logger.Handler(), slog.LevelError),
 	}
 
-	logger.Info("startings server", "addr", srv.Addr, "env", cfg.env)
+	logger.Info("starting server", "addr", srv.Addr, "env", cfg.env)
 
 	err := srv.ListenAndServe()
 	logger.Error(err.Error())