migrate on webpack built-in logger

[alexander-akait]

Issue description

Migrate on built-in webpack logger API https://webpack.js.org/api/logging/

Technical info

• Webpack Bundle Analyzer version: latest
• Webpack version: any
• Node.js version: any
• npm/yarn version: any
• OS: any

Debug info

Allow to filter and configure logger options from configuration(s) + allow to collect logs from stats

What other Webpack plugins were used?

Irrelevant

[valscion]

This would make webpack-bundle-analyzer only compatible with webpack v4.39.0 and forwards. Right now we're compatible with even webpack v3 if I remember correctly, so this would be a major version bump.

[alexander-akait]

We can't avoid breaking change using:

const logger = logging.getLogger ? logging.getLogger('webpack-bundle-analyzer') : oldLogger;

[valscion]

Ah cool idea! That would be a possible idea.

[jamesgeorge007]

I would love to give it a shot 🙌

[ronakmaheshwari]

Hey! I'd like to take a shot at this one. Before writing code, wanted to check in on a couple of things that touch public API behavior.

Plan: swap the custom Logger for webpack's built-in logger (compiler.getInfrastructureLogger(name)) across BundleAnalyzerPlugin.js and viewer.js. Bonus: this gives us time()/timeEnd() for free, which should help close #499 too.

Two questions:

1. logLevel option — right now it's plugin-local and filters our custom logger. Webpack's built-in logger doesn't have a per-plugin level; it's global via infrastructureLogging.level. I can either wrap the built-in logger to preserve logLevel exactly as-is, or drop our filtering and document that verbosity now follows the user's infrastructureLogging config (more webpack-native, but breaking). Which way would you want to go?

2. CLI mode — src/bin/analyzer.js has no live compiler (it reads a static stats.json), so it can't use the built-in logger. The custom Logger class would stay for CLI only; this migration is plugin-mode only.

Let me know if this tracks, happy to open a PR once I've got a steer on logLevel.

@valscion @alexander-akait

[evenstensberg]

Sure open a pr, should be trivial. Import the logger and remove old logging

[valscion]

Is there a middle ground where we would be able to have backwards-compatible change for one release and then we can later drop the compat support and bump the major version?