fix: respond with JSON Resource Descriptor Content-Type per RFC7033

routers/web/webfinger.go

@@ -118,4 +118,5 @@ func WebfingerQuery(ctx *context.Context) {
 		Aliases: aliases,
 		Links:   links,
 	})
+	ctx.Resp.Header().Set("Content-Type", "application/jrd+json")
 }

tests/integration/webfinger_test.go

@@ -48,6 +48,7 @@ func TestWebfinger(t *testing.T) {
 
 	req := NewRequest(t, "GET", fmt.Sprintf("/.well-known/webfinger?resource=acct:%s@%s", user.LowerName, appURL.Host))
 	resp := MakeRequest(t, req, http.StatusOK)
+	assert.Equal(t, resp.Header().Get("Content-Type"), "application/jrd+json")
 
 	var jrd webfingerJRD
 	DecodeJSON(t, resp, &jrd)