fix: return application/json for well-known and jwks

Author: nicolst

cmd/main.go

@@ -247,6 +247,7 @@ func WellKnown(host string) func(http.ResponseWriter, *http.Request) {
 	}
 	b, _ := json.Marshal(wellknown)
 	return func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
 		w.Write(b)
 	}
 }
@@ -257,6 +258,7 @@ func Jwks(s jwk.Set) (func(http.ResponseWriter, *http.Request), error) {
 		return nil, fmt.Errorf("marshal jwks: %w", err)
 	}
 	return func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
 		w.Write(jwksBytes)
 	}, nil
 }

cmd/main_test.go

@@ -0,0 +1,37 @@
+package main
+
+import (
+	"net/http/httptest"
+	"testing"
+
+	"github.com/lestrrat-go/jwx/v3/jwk"
+)
+
+func TestWellKnown(t *testing.T) {
+
+	wk := WellKnown("testing")
+
+	req := httptest.NewRequest("GET", "/", nil)
+	w := httptest.NewRecorder()
+
+	wk(w, req)
+	res := w.Result()
+
+	if contentType := res.Header.Get("Content-Type"); contentType != "application/json" {
+		t.Errorf("expected content-type application/json, got %q", contentType)
+	}
+}
+
+func TestJwks(t *testing.T) {
+	wk, _ := Jwks(jwk.NewSet())
+
+	req := httptest.NewRequest("GET", "/", nil)
+	w := httptest.NewRecorder()
+
+	wk(w, req)
+	res := w.Result()
+
+	if contentType := res.Header.Get("Content-Type"); contentType != "application/json" {
+		t.Errorf("expected content-type application/json, got %q", contentType)
+	}
+}