Identifier source mapping incorrect

[DylanPiercey]

When debugging a typescript file the identifiers do not seem to be mapping back correctly.

Disabling esbuilds minification (https://github.com/esbuild-kit/core-utils/blob/develop/src/esbuild/index.ts#L32) resolves the issue for me.

This is possibly an esbuild issue, but I wonder if it makes sense to turn off minification here for now, or maybe just to use the minifyWhitespace: true option instead which also works fine.

[DylanPiercey]

FYI @privatenumber it seems this issue is in fact with esbuild evanw/esbuild#1296 (comment). Id say it'd be good for now to turn off identifier minification to allow for proper debugging. Happy to put up a pr if you like.

[privatenumber]

Thanks for the report!

Do you mind providing a quick reproduction (inline code snippets is fine)? I'd like to investigate the problem.

[DylanPiercey]

@privatenumber if you create a file with any identifiers and run it with a debugger it will not let you hover over and inspect those identifiers.

Eg

test.ts

const abc = 1;

debugger;
console.log(abc);

Then running tsx --inspect ./test.ts and using whatever debugger you want you'll see if you hover over abc it will not show it's value. If you disable the minify option passed to esbuild you will be able to see the value.

Here you can see the variable got minified to c for me, but not reflected in the debugger:

But if I manually change the minify options in my node_modules for this package, I'll see:

[DylanPiercey]

Again the issue is technically with esbuild, but w/o the workaround here it makes debugging harder.

[privatenumber]

I'm OK with swapping minify and keepNames out with minifyWhitespace and minifySyntax.

I'm looking to add a small test to test against this behavior though and I can't think of one. I am using new Error().stack, but I'm not sure if source-map-support uses the names property in the stack.

Do you have any ideas?

[DylanPiercey]

@privatenumber the best I can come up with is to test against an error that includes the identifier name in the message, eg assignment before initialization like this:

test.ts

(() => abc = 1)();
let abc;

tsx ./test.ts

Yields

./test.ts:1
(() => abc = 1)();
       ^

ReferenceError: Cannot access 'a' before initialization

Removing the minify: true changes the error message to the actual identifier like this:

./test.ts:1
(() => abc = 1)();
       ^

ReferenceError: Cannot access 'abc' before initialization

[privatenumber]

@DylanPiercey Thanks!

@AisonSu I'll create a contributing guide later to explain how to set these up without a mono repo and why I didn't choose a mono repo.

[privatenumber]

FYI I'm considering re-enabling this now that esbuild supports names via evanw/esbuild#1296

[DylanPiercey]

👍