Merge pull request #19 from TingluoHuang/users/tihuang/decodepayload

decode snappy compressed base64 json.

package.json

@@ -13,7 +13,8 @@
  "react-codemirror2": "^7.1.0",
  "react-copy-to-clipboard": "^5.0.2",
  "react-dom": "^16.13.1",
- "react-scripts": "3.4.1"
+ "react-scripts": "3.4.1",
+ "snappyjs": "^0.6.1"
  },
  "scripts": {
  "start": "react-scripts start",

src/components/JSONFormatter/JSONFormatter.jsx

@@ -1,6 +1,8 @@
 import React, { Component } from "react";
 import { MuiThemeProvider, createMuiTheme } from '@material-ui/core/styles';
 import { UnControlled as CodeMirror } from 'react-codemirror2'
+import SnappyJS from 'snappyjs'
+import { Buffer } from "buffer";
 
 const zlib = require('zlib');
 require('codemirror/mode/javascript/javascript');
@@ -61,16 +63,30 @@ export class JSONFormatter extends Component {
 
  formatJSON(input) {
  if (input) {
+ var jsonString = "";
  if (!input.startsWith("0x")) {
- throw new Error("input needs to be a Hex String starts with '0x'.");
+ input = input.replace(/\r?\n|\r/g, "");
+ // check whether the input is a base64 string and then try use snappy to decompress it
+ var base64regex = /^([0-9a-zA-Z+/]{4})*(([0-9a-zA-Z+/]{2}==)|([0-9a-zA-Z+/]{3}=))?$/;
+ if (base64regex.test(input)) {
+ var uncompressed = SnappyJS.uncompress(Buffer.from(input, 'base64'));
+ let utf8decoder = new TextDecoder()
+ jsonString = utf8decoder.decode(uncompressed);
+ }
+ else {
+ throw new Error("input needs to be a Hex String starts with '0x' or valid base64 string.");
+ }
  }
- input = input.substring(2);
- var hex = Buffer.from(input, 'hex');
- if (input.toLowerCase().startsWith("1f8b")) {
- // gzip string, need to unzip first
- hex = zlib.gunzipSync(hex);
+ else {
+ input = input.substring(2);
+ var hex = Buffer.from(input, 'hex');
+ if (input.toLowerCase().startsWith("1f8b")) {
+ // gzip string, need to unzip first
+ hex = zlib.gunzipSync(hex);
+ }
+ jsonString = hex.toString('utf-8');
  }
- var jsonString = hex.toString('utf-8');
+
  var parsedData = JSON.parse(jsonString);
  var outputText = JSON.stringify(parsedData, null, 4);
  return outputText;