add CSV support #27

src/fileUtils.js

@@ -50,5 +50,21 @@ export default {
 
   readFile (path) {
     return fetch(path)
+  },
+
+  readAsArrayBuffer (file) {
+    const fileReader = new FileReader()
+
+    return new Promise((resolve, reject) => {
+      fileReader.onerror = () => {
+        fileReader.abort()
+        reject(new DOMException('Problem parsing input file.'))
+      }
+
+      fileReader.onload = () => {
+        resolve(fileReader.result)
+      }
+      fileReader.readAsArrayBuffer(file)
+    })
   }
 }