swc/ecmascript/minifier/README.md
강동윤 b02e189d07
feat(es/minifier): Implement more rules (#1871)
swc_ecma_codegen:
 - Fix codegen of `U+0028` and `U+0029`. 

swc_ecma_minifier:
 - Implement MVP.

swc_ecma_transforms_base:
 - `fixer`: Handle seq/await in rhs of for-of.
2021-07-30 10:11:27 +09:00

1.2 KiB

Minifier

EcmaScript minifier for the swc project. This is basically a port of terser.

Note

Currently name mangler is very simple. To focus on creating a MVP, I (kdy1) will use simple logic for name mangler and implement the content-aware name mangler after publishing first non-beta version.

Testing

Real-library tests

You can use vscode to see diffs. Select a file from tests/projects/output and select the corresponding file from tests/projects/refs. Then you can right click to see an option to open diff.

Splitting a library test

Extracting only subset from a library test makes development much easier.

Split status:

  • angular-1.2.5
  • backbone-1.1.0
  • jquery-1.9.1
  • jquery.mobile-1.4.2
  • mootools-1.4.5
  • underscore-1.5.2
  • yui-3.12.0

Tests from terser

Tests ported from terser has

  • input.js
  • config.json
  • mangle.json (if name mangling is enabled)
  • output.js (if exists and can be modified if our one is better or due to lack of frequency-aware base54)
  • output.terser.js (if exists)

Copying tests

Replace the content of terser/test/compress.js with it of scripts/compress.js and run npm run test:compress