Add error types on frontend

src/frontend/apis/index.js

 import Promise from 'bluebird';
 import axios from 'axios';
+import { RuntimeError } from '/common/error';
 
 axios.interceptors.response.use(
   response => response.data,
@@ -73,7 +74,7 @@ const TracerApi = {
     if (jsWorker) jsWorker.terminate();
     jsWorker = new Worker('/api/tracers/js');
     jsWorker.onmessage = e => resolve(e.data);
-    jsWorker.onerror = reject;
+    jsWorker.onerror = e => reject(new RuntimeError(e.message));
     jsWorker.postMessage(code);
   }),
   java: POST('/tracers/java'),

src/frontend/common/error.js

+class ApplicationError extends Error {
+  constructor(message) {
+    super(message);
+    this.name = this.constructor.name;
+  }
+}
+
+class CompileError extends ApplicationError {
+}
+
+class RuntimeError extends ApplicationError {
+}
+
+export {
+  ApplicationError,
+  CompileError,
+  RuntimeError,
+};
\ No newline at end of file

src/frontend/core/tracerManager.jsx

@@ -4,6 +4,7 @@ import { extension } from '/common/util';
 import { Array1DData, Array2DData, ChartData, Data, GraphData, LogData } from '/core/datas';
 import { Array1DRenderer, Array2DRenderer, ChartRenderer, GraphRenderer, LogRenderer, Renderer } from '/core/renderers';
 import { TracerApi } from '/apis';
+import { CompileError } from '/common/error';
 
 class TracerManager {
   constructor() {
@@ -158,7 +159,7 @@ class TracerManager {
     if (ext in TracerApi) {
       return TracerApi[ext]({ code: content });
     } else {
-      return Promise.reject(new Error('Language Not Supported'));
+      return Promise.reject(new CompileError('Language Not Supported'));
     }
   }