kdy1 / minifier-test-script

minifier-test-script

try.mjs is a script to help debugging swc minifier. The script creates a commit for each combination of minifier options. It first disables one option at a time, and it then disables two options at a time.

If your app is broken with default config but it works with specific option disabled, it means there's a bug related to the specific option. The swc minifier is 20K+ LoCs so looking at all code is impractical, but if the scope is reduced to a single option, we can debug it.

Options

--dry-run                       Show operations without actually applying it.
--upstream-branch=<name>        Use <name> as the **prefix** of the name of upstream branch.
--dir=<path/to/dir>             Run operations in <path/to/dir>. Useful for monorepos. Can be specified multiple time to use multiple next.js applications.

Steps

1. Modify next.config.js

Add

const compressConfig = require("./swc-compress.json");

to the top and add

{
  experimental: {
    swcMinifyDebugOptions: {
      compress: compressConfig,
    }
  }
}

to your export.

2. Run script

Run try.mjs using absolute path, like ~/src/minifier-test-script/try.mjs.