[Bugfix] fail readURL on http code > 399

openapi3/swagger_loader.go

@@ -113,6 +113,9 @@ func (swaggerLoader *SwaggerLoader) readURL(location *url.URL) ([]byte, error) {
 			return nil, err
 		}
 		defer resp.Body.Close()
+		if resp.StatusCode > 399 {
+			return nil, fmt.Errorf("request returned status code %d", resp.StatusCode)
+		}
 		return ioutil.ReadAll(resp.Body)
 	}
 	if location.Scheme != "" || location.Host != "" || location.RawQuery != "" {

openapi3/swagger_loader_http_error_test.go

@@ -0,0 +1,55 @@
+package openapi3
+
+import (
+	"fmt"
+	"net/http"
+	"net/http/httptest"
+	"net/url"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestLoadFromRemoteURLFailsWithHttpError(t *testing.T) {
+	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(http.StatusBadRequest)
+		fmt.Fprint(w, "")
+	}))
+	defer ts.Close()
+
+	spec := []byte(`
+{
+    "openapi": "3.0.0",
+    "info": {
+        "title": "",
+        "version": "1"
+    },
+    "paths": {
+        "/test": {
+            "post": {
+                "responses": {
+                    "default": {
+                        "description": "test",
+                        "headers": {
+                            "X-TEST-HEADER": {
+                                "$ref": "` + ts.URL + `/components.openapi.json#/components/headers/CustomTestHeader"
+                            }
+                        }
+                    }
+                }
+            }
+        }
+    }
+}`)
+
+	loader := NewSwaggerLoader()
+	loader.IsExternalRefsAllowed = true
+	swagger, err := loader.LoadSwaggerFromDataWithPath(spec, &url.URL{Path: "testdata/testfilename.openapi.json"})
+
+	require.Nil(t, swagger)
+	require.EqualError(t, err, fmt.Sprintf("error resolving reference \"%s/components.openapi.json#/components/headers/CustomTestHeader\": request returned status code 400", ts.URL))
+
+	swagger, err = loader.LoadSwaggerFromData(spec)
+	require.Nil(t, swagger)
+	require.EqualError(t, err, fmt.Sprintf("error resolving reference \"%s/components.openapi.json#/components/headers/CustomTestHeader\": request returned status code 400", ts.URL))
+}