Aggressive inlining causes double the optimal filesize

[mbkv]

Bug report or Feature request?
sub optimal output

Version (complete output of terser -V or specific git commit)

terser 5.19.4

Complete CLI command or minify() options used

    const minified = await minifyJS(
      { "router.js": file },
      {
        sourceMap: {
          includeSources: true,
          url: "router.js.map",
        },
      },
    );

terser input

https://github.com/mbkv/mbkv.io/blob/4cc82a16037f418071d4df4072b064a53b54be89/markdown/router.js

terser output or error

https://pastebin.com/tCr6NkBT

Expected result

a prettified version of the pastebin shows that terser is inlining "pushHistory" which effectively causes the entire file size to double. Playing around with router.js, if you remove the inner function, and just do a try/catch, it stops it from trying to inline it which suggests it was not intended

the fix for me is to add module: true to the options

[fabiosantoscode]

I appreciate the report!

This is happening because inline and unused are sometimes out of sync. It seems that inline knows that this const variable will not assign to the global object like a var would, but unused doesn't.

The workaround is to enable the toplevel: true which makes Terser able to remove variables on the top level of the script (IE assume that var a = 1 doesn't create window.a)

[fabiosantoscode]

Minimal repro (default options):

const dropped_func = () => {
  console.log("PASS")
}

export const kept_func = () => {
    dropped_func()
}

[mbkv]

Thanks for looking into it!