[Bug]: `module.resolveFully` cannot work with remote execution

[Olsworn]

What happened?

Running the swc transpiler through ts_project with module.resolveFully set to true in .swcrc leads to different outputs when remote execution is enabled than when running locally.

This is due to only passing the file to transpile as input to the swc_action, and not the other source files / transpiled files from dependencies.

Version

bazel: 9.0.0
aspect_rules_ts: 3.8.6
aspect_rules_swc: 2.6.2
Os: Linux x86_64

How to reproduce

Have a `.ts` file import a file from a directory with an index file, set resolveFully to true in .swcrc.

main.ts:

import { something } from "./folder";
console.log(something);


folder/index.ts:

const something: string = "something";
export { something };


Without remote execution:
main.js:

import { something } from "./folder/index.js";
console.log(something);


With remote execution:
main.js:

import { something } from "./folder";
console.log(something);

Any other information?

This case is a bit tricky to handle, as a fix might impact performance.

[jbedard]

We can't do this by default, that would destroy performance. Do you have a suggestion for how you'd want to accomplish this? My suggestion would be to never do this 😅

[Olsworn]

Possibly making such a behavior "opt-in"?

I see two different cases:

1. The imported module is part of the same project (I believe should be the most common case)
2. The imported module is part of dependencies

For 1. adding an option to the rule to pass all files from "srcs" to the input array.

It could be an option to pass to the transpiler through partial.make

partial.make(
  _swc,
  ...
  opt_in_param = True,
  ...
)

Then do something akin to this:

diff --git swc/private/swc.bzl swc/private/swc.bzl
index 1d6f910..04589e6 100644
--- swc/private/swc.bzl
+++ swc/private/swc.bzl
@@ -323,6 +323,9 @@ def _swc_impl(ctx):
             },
         })])
 
+    if ctx.attr.opt_in_param or ctx.attr.output_dir:
+        inputs.extend(ctx.files.srcs)
+
     if ctx.attr.output_dir:
         if len(ctx.attr.srcs) != 1:
             fail("Under output_dir, there must be a single entry in srcs")
@@ -330,8 +333,6 @@ def _swc_impl(ctx):
             fail("Under output_dir, the srcs must be directories, not files")
         output_dir = ctx.actions.declare_directory(ctx.attr.out_dir if ctx.attr.out_dir else ctx.label.name)
 
-        inputs.extend(ctx.files.srcs)
-
         output_sources = [output_dir]
 
         args.add_all(["--out-dir", output_dir], expand_directories = False)

For 2. I do not have an idea that wouldn't destroy performance, so relying on an option such as jsc.rewriteRelativeImportExtensions instead is a preferred approach.

Either way I believe these should be documented somewhere.

[jbedard]

I think I'd just want to add support for swc(data) that gets appended to the inputs 100% of the time. Then if a user wants to pass the same array of srcs as data as well then they can do so. I would highly discourage and never document such a thing though.