fix: nerf property access to better support Editor test harness

src/core/index.js

@@ -131,6 +131,9 @@ module.exports = function SwaggerUI(opts) {
   var system = store.getSystem()
 
   const downloadSpec = (fetchedConfig) => {
+      if(typeof constructorConfig !== "object") {
+        return system
+      }
     let localConfig = system.specSelectors.getLocalConfig ? system.specSelectors.getLocalConfig() : {}
     let mergedConfig = deepExtend({}, localConfig, constructorConfig, fetchedConfig || {}, queryConfig)
 
@@ -140,7 +143,10 @@ module.exports = function SwaggerUI(opts) {
     }
 
     store.setConfigs(mergedConfig)
-    system.configsActions.loaded()
+
+    if(system.configsActions) {
+      system.configsActions.loaded()
+    }
 
     if (fetchedConfig !== null) {
       if (!queryConfig.url && typeof mergedConfig.spec === "object" && Object.keys(mergedConfig.spec).length) {

src/core/plugins/spec/wrap-actions.js

@@ -12,7 +12,7 @@ export const updateJsonSpec = (ori, {specActions}) => (...args) => {
 
   // Trigger resolution of any path-level $refs.
   const [json] = args
-  const pathItems = get(json, ["paths"])
+  const pathItems = get(json, ["paths"]) || {}
   const pathItemKeys = Object.keys(pathItems)
 
   pathItemKeys.forEach(k => {