Allow for un-captured route of config.yml (decaporg#1182)

src/actions/config.js

@@ -75,6 +75,21 @@ function parseConfig(data) {
   return config;
 }
 
+async function getConfig(file, isPreloaded) {
+  const response = await fetch(file, { credentials: 'same-origin' });
+  if (response.status !== 200) {
+    if (isPreloaded) return parseConfig('');
+    throw new Error(`Failed to load config.yml (${ response.status })`);
+  }
+  const contentType = response.headers.get('Content-Type') || 'Not-Found';
+  const isYaml = contentType.indexOf('yaml') !== -1;
+  if (!isYaml) {
+    console.log(`Response for ${ file } was not yaml. (Content-Type: ${ contentType })`);
+    if (isPreloaded) return parseConfig('');
+  }
+  return parseConfig(await response.text());
+}
+
 export function configLoaded(config) {
   return {
     type: CONFIG_SUCCESS,
@@ -115,19 +130,12 @@ export function loadConfig() {
 
     try {
       const preloadedConfig = getState().config;
-      const response = await fetch('config.yml', { credentials: 'same-origin' })
-      const requestSuccess = response.status === 200;
-
-      if (!preloadedConfig && !requestSuccess) {
-        throw new Error(`Failed to load config.yml (${ response.status })`);
-      }
-
-      const loadedConfig = parseConfig(requestSuccess ? await response.text() : '');
+      const loadedConfig = await getConfig('config.yml', preloadedConfig && preloadedConfig.size > 1);
 
       /**
        * Merge any existing configuration so the result can be validated.
        */
-      const mergedConfig = mergePreloadedConfig(preloadedConfig, loadedConfig)
+      const mergedConfig = mergePreloadedConfig(preloadedConfig, loadedConfig);
       const config = flow(validateConfig, applyDefaults)(mergedConfig);
 
       dispatch(configDidLoad(config));