add json pretty prints for /healthz (#20)

The recommended way to debug zap is to hit the endpoint /varz to see what the config is parsed into. However, it's not very human readable. Added pretty formatting to the endpoint to make life easier for people.

web.go

@@ -7,6 +7,7 @@ import (
 	"net/http"
 	"sync"
 
+	"encoding/json"
 	"github.com/Jeffail/gabs"
 )
 
@@ -79,6 +80,17 @@ func HealthHandler(w http.ResponseWriter, r *http.Request) {
 // VarsHandler responds to /varz request and prints config.
 func VarsHandler(c *context, w http.ResponseWriter, r *http.Request) (int, error) {
 	w.WriteHeader(http.StatusOK)
-	io.WriteString(w, "Config: "+c.config.String())
+	io.WriteString(w, jsonPrettyPrint(c.config.String()))
 	return 200, nil
 }
+
+// https://stackoverflow.com/a/36544455/5117259
+func jsonPrettyPrint(in string) string {
+	var out bytes.Buffer
+	err := json.Indent(&out, []byte(in), "", "\t")
+	if err != nil {
+		return in
+	}
+	out.WriteString("\n")
+	return out.String()
+}

web_test.go

@@ -236,12 +236,12 @@ func BenchmarkIndexHandler(b *testing.B) {
 }
 
 func TestHealthCheckHandler(t *testing.T) {
-	Convey("When we GET /zealthz", t, func() {
-		req, err := http.NewRequest("GET", "/zealthz", nil)
+	Convey("When we GET /healthz", t, func() {
+		req, err := http.NewRequest("GET", "/healthz", nil)
 		So(err, ShouldBeNil)
 		req.Host = "sd"
 
-		// We create a RegonseRecorder (which satisfies http.RegonseWriter) to record the regonse.
+		// We create a ResponseWriter (which satisfies http.ResponseWriter) to record the response.
 		rr := httptest.NewRecorder()
 		handler := http.HandlerFunc(HealthHandler)
 		handler.ServeHTTP(rr, req)
@@ -271,11 +271,23 @@ func TestVarzHandler(t *testing.T) {
 
 			Convey("We should get a 200", func() {
 				So(rr.Code, ShouldEqual, http.StatusOK)
-				conf, err := yaml.YAMLToJSON(c.Bytes())
-				So(err, ShouldBeNil)
-				d, err := yaml.YAMLToJSON(rr.Body.Bytes())
+			})
+			Convey("It should be valid json", func() {
+				_, err := yaml.YAMLToJSON(rr.Body.Bytes())
 				So(err, ShouldBeNil)
-				So(string(d), ShouldContainSubstring, string(conf))
+			})
+			Convey("It should equal the config file", func() {
+				conf, err := yaml.YAMLToJSON(c.Bytes())
+				So(err, ShouldBeNil) // sanity check.
+
+				resp, err := yaml.YAMLToJSON(rr.Body.Bytes())
+				So(err, ShouldBeNil) // sanity check.
+
+				// We get a nicely formatted response, but when we feed it into YAMLToJSON it collapses our nice
+				// newlines. As a result, directly comparing the byte arrays here is a nogo. Therefore, we cheat
+				// and utilize the separately tested jsonPrettyPrint to idempotently indent the JSON and compare that.
+				// This does not work: "So(resp, ShouldEqual, []byte(jsonPrettyPrint(string(conf))))"
+				So(jsonPrettyPrint(string(resp)), ShouldEqual, jsonPrettyPrint(string(conf)))
 			})
 		})
 	})