[Bug]: Make variable substitution corrupts regex (or escaping rules undocumented!)

[ahmedneilhussain]

What happened?

Porting some code from build_bazel_rules_nodejs to use rules_js, I replaced a genrule with js_run_binary. Command line flags containing regexes that worked fine with genrule get corrupted when passed to the args attribute of js_run_binary.

These used to work fine using genrule:

    "--ignore-custom-fragments='/{{[{]?(.*?)[}]?}}/'",
    "--ignore-custom-fragments='/{%(.*?)%}/'",

In js_run_binary they get corrupted, and in fact as it stands cause the shell script runner to blow up before even invoking the binary, I think because the input gets truncated after the first % of the second CLI arg and you get a shell complaint about the unmatched quote.

I presume makefile variable expansion is causing the problem but I would have expected the substitution to behave the same as native genrule?

Version

Development (host) and target OS/architectures: MacOS Ventura 13.3.1a/x86

Output of bazel --version:
bazel 7.0.0-pre.20230316.2

Version of the Aspect rules, or other relevant rules from your
WORKSPACE or MODULE.bazel file:
https://github.com/aspect-build/rules_js/archive/002397780d51735f1a98b362fca7018df31e85ac.tar.gz
(needed to use a commit because a fix for newer syntax of pnpm-lock.yaml files isn't/wasn't yet in a released build).

Language(s) and/or frameworks involved:

How to reproduce

Build a simple node binary that echoes its arguments and pass those in - should be malformed.

Any other information?

No response