Fixes #278 filter files by extension

src/backends/github/API.js

@@ -155,7 +155,14 @@ export default class API {
   listFiles(path) {
     return this.request(`${ this.repoURL }/contents/${ path }`, {
       params: { ref: this.branch },
-    });
+    })
+    .then(files => {
+      if (!Array.isArray(files)) {
+        throw new Error(`Cannot list files, path ${path} is not a directory but a ${files.type}`);
+      }
+      return files;
+    })
+    .then(files => files.filter(file => file.type === "file"));
   }
 
   readUnpublishedBranchFile(contentKey) {

src/backends/github/implementation.js

@@ -1,6 +1,7 @@
 import semaphore from "semaphore";
 import AuthenticationPage from "./AuthenticationPage";
 import API from "./API";
+import { fileExtension } from '../../lib/pathHelper'
 
 const MAX_CONCURRENT_DOWNLOADS = 10;
 
@@ -39,8 +40,9 @@ export default class GitHub {
     return Promise.resolve(this.token);
   }
 
-  entriesByFolder(collection) {
+  entriesByFolder(collection, extension) {
     return this.api.listFiles(collection.get("folder"))
+    .then(files => files.filter(fileExtension(file.name) === extension))
     .then(this.fetchFiles);
   }