fix(webpack): enable devtool for dev mode

[clarkdo]

Description

TODO:

• Test dev mode memory usage
• Update doc for default value

[codecov-io]

Codecov Report

Merging #6495 into dev will increase coverage by 0.03%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##              dev    #6495      +/-   ##
==========================================
+ Coverage   95.67%   95.71%   +0.03%     
==========================================
  Files          79       79              
  Lines        2708     2708              
  Branches      699      700       +1     
==========================================
+ Hits         2591     2592       +1     
+ Misses        101      100       -1     
  Partials       16       16

Flag	Coverage Δ
#e2e	100% <ø> (ø)	⬆️
#fixtures	50.59% <100%> (ø)	⬆️
#unit	92.35% <100%> (+0.03%)	⬆️

Impacted Files	Coverage Δ
packages/webpack/src/config/base.js	92% <ø> (-0.08%)	⬇️
packages/webpack/src/config/client.js	98.11% <100%> (+0.03%)	⬆️
packages/vue-renderer/src/renderer.js	94.3% <0%> (+0.81%)	⬆️

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[pimlie]

What exactly is the default value currently? Would it be an idea to just set it to cheap-module-eval-source-map by default as for the server build?

I tried this locally but think the errors are still not as helpful as they can be

[clarkdo]

I think the default value of webpack may have more consideration and try to keep best practice in both readability and performance. And this config can be easily set via nuxt.config as well.

[clarkdo]

The default value is eval in dev mode which includes almost everything in source code

[pimlie]

Looking at https://webpack.js.org/configuration/devtool/, wouldnt it be best for DX to have at least the original source quality by default? eval has the quality generated code which is still not really helpful right?

As you said, if performance is an issue users can always set it back to eval themselves

[pimlie]

LGTM, thanks!