Should inject banner code after use strict

[anothertempore]

Environment

[email protected], @sentry/[email protected]

Steps to Reproduce

This injection logic should be placed below use strict:

sentry-javascript-bundler-plugins/packages/webpack-plugin/src/index.ts

Lines 157 to 160 in febe9ce

	new BannerPlugin({
	raw: true,
	include: /\.(js|ts|jsx|tsx|mjs|cjs)$/,
	banner: injectionCode,

In our case, TerserPlugin removes all the use strict because it is not at the top of the file.

Possible Solution

A possible solution is to do like below:

new BannerPlugin({
  raw: true,
  include: /\.(js|ts|jsx|tsx|mjs|cjs)$/,
  banner: injectionCode,
  footer: true,
})

However, from webpack side, better not to use BannerPlugin to inject code, it's not designed for this. Can refer to webpack/webpack#18202

[lforst]

Hi, thanks for writing in. We will most likely not dedicate much time to this in the short to medium-term future.

For posterity, I used the banner plugin because it was the most reliable way of injecting stuff at the top of bundles while preserving sourcemaps. We would likely want to build something similar ourselves, but I recall that doing non-trivial code modifications and preserving source maps is a major PITA. I legit couldn't get it to work.