Followed source map instructions, but line numbers are wrong, etc

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Package + Version

• @sentry/node - 5.18.1
• @sentry/integrations - 5.18.1
• @sentry/webpack-plugin - 1.11.1

Description

I’ve followed the instructions on source maps to the best of my knowledge. I’m trying this out with a Serverless Framework setup.

It’s quite an improvement over how reporting looked before I followed the steps, but the line number is totally wrong and the module name is missing. There’s also still remnants of webpack variable names.

https://sentry.io/organizations/reelcrafter/issues/1749922899/?project=5298557

webpack.config.js

const path = require("path");
// eslint-disable-next-line import/no-unresolved
const slsw = require("serverless-webpack");
const SentryPlugin = require("@sentry/webpack-plugin");

module.exports = {
  entry: slsw.lib.entries,
  devtool: "source-map",
  output: {
    libraryTarget: "commonjs",
    filename: "[name].js",
    path: path.join(__dirname, ".webpack"),
  },
  mode: "development",
  target: "node",
  module: {
    rules: [
      {
        test: /\.js$/, // include .js files
        enforce: "pre", // preload the jshint loader
        exclude: /node_modules/, // exclude any and all files in the node_modules folder
        include: __dirname,
        use: [
          {
            loader: "babel-loader",
          },
        ],
      },
    ],
  },
  plugins: [
    new SentryPlugin({
      release: process.env.RELEASE,
      include: "./.webpack",
    }),
  ],
};

test.js

import * as Sentry from "@sentry/node";
import { RewriteFrames } from "@sentry/integrations";

Sentry.init({
  dsn: "https://xx",
  release: process.env.RELEASE,
  integrations: [new RewriteFrames()],
});

/**
 ...
*/

[kamilogorek]

WARNING in configuration. The ‘mode’ option has not been set, webpack will fallback to ‘production’ for this value. Set ‘mode’ option to ‘development’ or ‘production’ to enable defaults for each environment.

😶

I found the main issue. It’s TerserPlugin messing around with the source code.

optimization: {
  minimize: false,
},

Add this to your webpack config and you should be good no matter what mode is set! (this is the only change I did base on your current repo state).

You can play around with TerserPlugin default options to find which exactly is the culprit if you want to use it nonetheless - https://webpack.js.org/plugins/terser-webpack-plugin/#terseroptions

BTW, I appreciate all your time and help! Don’t worry, I’m a paid Sentry customer. 😆

Anytime, I’m curious myself what’s going in here 😄

[ipetrini]

For anyone who might still have problems with the source map line numbers while using Terser plugin, I could get it working properly by disabling the following compress options in terserOptions:

compress: {
  conditionals: false,
  sequences: false
}