[Proposal] consolidating @swc/cli entrypoint for features

[kwonoj]

Description

This proposal attempts to describe proposals for potential changes to @swc/cli's entrypoint.

Currently, @swc/cli offers differently named entrypoint for individual features. swc is for the main transpiler, spack (to be renamed to swcpack in v2) is for the bundler.

Instead of adding each entrypoint name for the each features, I'd like to propose consolidate swc as single entrypoint for any cli command execution. Each features can be represented as subcommand instead. Think how git works with its subcommand.

Illustrated example

All of subcommands are pseudo, subject to change and only being used for example illustration.

• top-level command

$> swc // same as swc --help
$> swc --help

... list of subcommands and its description

For easier migration, V2 will prints out deprecated warning and forward args to swc compile. V3 will actually deprecate code paths to let top-level invocation for the compilation.

• Invoke compiler

// Identical to existing swc/cli commandline flags
swc compile --help
swc compile ./file.js
swc compile ...

• Invoke bundler

swc bundle --help
swc bundle ./file.js

Pros

• Single entrypoint to cli, no need to have new names for each features
• Easily extendable subcommand when adapt new features

Cons

• Slightly more complex args handling logics, but I guess pushing forward Reimplement CLI in rust #1589 fully (making cli in fully-rust, does not invoke node.js at all) would allow better args parser.

[kdy1]

I love this idea. We can add minify too.

[kwonoj]

I'll start some work on the rust side for non-breaking changes to support these. Can slowly migrate things over @swc/cli for v2 and beyond once we have it.