React - Chrome does not report undefined JavaScript object property. Crashes

Question

Since im building my webapp with React, when i try to set something into an undefined object property, the code processing crashes (reproducible with breakpoint debugging) and no errors are shown in the console log. Also the chrome react extension does not give me any errors.

So to finding a bug is more time consuming that it should be.

let changedJsonResponse = jsonResponse;
changedJsonResponse.data = newTableData; // changedJsonResponse.data is undefined

// throws no error & code proccess crashes

webpack.config.js

const webpack = require('webpack');
const path = require('path');

let config = {
    devtool: 'eval-source-map',
    entry: {
        FooManagement: ['babel-polyfill', './domains/FooManagement/entry.jsx'],
    },
    output: {
        path: path.resolve(__dirname, '../web/react/'),
        filename: '[name].js'
    },
    externals: {
        'jquery': 'window.jQuery',
        'bootbox': 'window.bootbox',
    },
    resolve: {
        alias: {
            alias_shared: path.resolve(__dirname, 'shared'),
        },
    },
    module: {
        rules: [
            {
                test: /\.jsx?$/,
                exclude: [/node_modules/],
                loader: 'babel-loader',
                options: {presets: ['es2015', 'react']}
            },
            {
                test: /\.css/,
                loader: 'style-loader!css-loader'
            }
        ]
    }
};

module.exports = config;

package.json

{
  "author": "myself",
  "version": "0.0.1",
  "description": "",
  "main": "index.jsx",
  "scripts": {
    "watch": "webpack -d --watch",
    "build": "webpack -p"
  },
  "devDependencies": {
    "babel-core": "^6.26.0",
    "babel-loader": "^7.1.2",
    "babel-polyfill": "^6.26.0",
    "babel-preset-es2015": "^6.24.1",
    "babel-preset-react": "^6.24.1",
    "css-loader": "^0.28.7",
    "style-loader": "^0.19.0",
    "webpack": "^3.8.1"
  },
  "dependencies": {
    "axios": "^0.16.2",
    "dateformat": "^3.0.2",
    "is-uuid": "^1.0.2",
    "lodash": "^4.17.4",
    "react": "^16.0.0",
    "react-cropper": "^1.0.1",
    "react-dom": "^16.0.0",
    "react-dropzone": "^4.2.3",
    "react-router-dom": "^4.2.2",
    "react-switchery-component": "0.0.7",
    "uuid": "^3.1.0"
  }
}

Chrome version: 62.0.3202.94

What is the error here changedJsonResponse.data = newTableData; ? — Madhavan.V
– Madhavan.V, Commented Dec 14, 2017 at 7:47
Okay, changedJsonResponse.data is undefined. If changedJsonResponse exists, like { }, then this will work. Am I misunderstood you question? — Madhavan.V
– Madhavan.V, Commented Dec 14, 2017 at 7:49
Like i described in the code block, the property data is undefined. // changedJsonResponse.data is undefined. I noticed that the problem comes also when setting something into an undefined variable. — fabpico
– fabpico, Commented Dec 14, 2017 at 7:49
If changedJsonResponse is some object and changedJsonResponse.data is undefined then changedJsonResponse.data = newTableData will not throw any error. — Prakash Sharma
– Prakash Sharma, Commented Dec 14, 2017 at 7:49
@Prakashsharma Thats the problem. But it should throw an error, the code proccess is also halted then. — fabpico
– fabpico, Commented Dec 14, 2017 at 7:52

fabpico · Accepted Answer · 2018-04-05 11:32:21Z

0

I was able to catch those errors in Axios .catch.

After a while i found the cause of the problem.

answered Apr 5, 2018 at 11:32

fabpico

2,9864 gold badges32 silver badges50 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

React - Chrome does not report undefined JavaScript object property. Crashes

1 Answer 1

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related