Minifying JavaScript with Unicode identifiers next to keywords produces syntax error

[satgo1546]

$ esbuild --version
0.17.7
$ cat index.js
a.π in a
$ esbuild index.js --minify --charset=utf8
a.πin a;
$ node -e 'a.πin a;'
[eval]:1
a.πin a;
      ^

SyntaxError: Unexpected identifier 'a'
    at ...

The same goes for other keywords such as of and instanceof.

Meanwhile, the problem is mitigated by --charset=ascii.

$ esbuild index.js --minify
a.\u03C0 in a;

[evanw]

Thanks for the report. Looks like esbuild is only looking at the previous byte for this, which is incorrect for Unicode. I’ll fix this in the next release.