Extract symbolicateStackTrace into its own module

Summary:
Having a function that symbolicates any given stack trace
is convenient, e.g. in #7459

More cleanup to follow.

Reviewed By: davidaurelio

Differential Revision: D3348616

fbshipit-source-id: 6313ec837869c6080829c811345a06aa1b2dcd21

Libraries/JavaScriptAppEngine/Initialization/symbolicateStackTrace.js

@@ -0,0 +1,32 @@
+/**
+ * Copyright (c) 2015-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ *
+ * @providesModule symbolicateStackTrace
+ * @flow
+ */
+'use strict';
+
+const {fetch} = require('fetch');
+const getDevServer = require('getDevServer');
+
+import type {StackFrame} from 'parseErrorStack';
+
+async function symbolicateStackTrace(stack: Array<StackFrame>): Promise<Array<StackFrame>> {
+  const devServer = getDevServer();
+  if (!devServer.bundleLoadedFromServer) {
+    throw new Error('Bundle was not loaded from the packager');
+  }
+  const response = await fetch(devServer.url + 'symbolicate', {
+    method: 'POST',
+    body: JSON.stringify({stack}),
+  });
+  const json = await response.json();
+  return json.stack;
+}
+
+module.exports = symbolicateStackTrace;