Optimize startup performance

I would like meow to have as little impact on startup performance as possible.

#67 is one way to improve that.

I will also do some profiling with DevTools to see what else can be optimized.

From memory, the

Line 78 in 646f30b

normalizePackageData(pkg);

is pretty slow, so we could defer normalizing the package.json data until the user calls cli.pkg. We only really need the description field ourselves, which doesn't need to be normalized.

I'm open to other ideas and help with this.

I've just profiled a really small CLI app that takes ~2 seconds to run using the V8 profiler. This package came up as first for compile time. As you say, the normalizePackageData is the most expensive, because normalize-package-data even parses the license field (using spdx-expression-parse) and parses all URLs with RegExps.

My suggestion would be to avoid reading the package.json if the user passes a pkg: false option, and the --help and --version flags are not present.

We don’t need the normalize stuff in Meow itself. So we could actually turn it off and only do it on demand if the user accesses the exported .pkg property.