feat(bazel): allow for linker mappings and external NPM package extra…

…ction in extract rule

Updates the extract JS module output macro to support:

* The extraction of external NPM package sources
* The forwarding of linker mappings of the specified dependencies.

Both of these things would be needed for extracting full-devmode sources
in a way so that they can be fed into e.g. `esbuild` with proper module
resolution. This is done in `angular/components` for example to speed up
local development as devmode output is already ESM and ESBuild would by
default request both devmoe + prodmode output.

In general this rule is designed to help with the current situation of
still building devmode + prodmode. In the future we can fully remove
this rule if there is only a single output flavor using ESM!.

bazel/extract_js_module_output.bzl

@@ -1,4 +1,5 @@
-load("@build_bazel_rules_nodejs//:providers.bzl", "DeclarationInfo", "JSEcmaScriptModuleInfo", "JSModuleInfo", "JSNamedModuleInfo")
+load("@build_bazel_rules_nodejs//:providers.bzl", "DeclarationInfo", "ExternalNpmPackageInfo", "JSEcmaScriptModuleInfo", "JSModuleInfo", "JSNamedModuleInfo", "node_modules_aspect")
+load("@build_bazel_rules_nodejs//internal/linker:link_node_modules.bzl", "LinkerPackageMappingInfo", "module_mappings_aspect")
 
 """Converts a provider name to its actually Starlark provider instance."""
 
@@ -15,13 +16,25 @@ def _name_to_js_module_provider(name):
 
 def _extract_js_module_output_impl(ctx):
     js_module_provider = _name_to_js_module_provider(ctx.attr.provider)
+    mappings = {}
     depsets = []
+
     for dep in ctx.attr.deps:
         # Include JavaScript sources (including transitive outputs) based on the
         # configured JavaScript module provider.
         if js_module_provider in dep:
             depsets.append(dep[js_module_provider].sources)
 
+        # If external NPM package sources should be included, we also capture the
+        # sources (including transitive external NPM packages).
+        if ctx.attr.include_external_npm_packages and ExternalNpmPackageInfo in dep:
+            depsets.append(dep[ExternalNpmPackageInfo].sources)
+
+        # If we intend to forward linker mappings, capture first-party package
+        # linker mappings and collect them in a dictionary that we will re-expose.
+        if ctx.attr.forward_linker_mappings and LinkerPackageMappingInfo in dep:
+            mappings.update(dep[LinkerPackageMappingInfo].mappings)
+
         # Based on whether declarations should be collected, extract direct
         # and transitive declaration files using the `DeclarationInfo` provider.
         if ctx.attr.include_declarations and DeclarationInfo in dep:
@@ -37,7 +50,10 @@ def _extract_js_module_output_impl(ctx):
 
     sources = depset(transitive = depsets)
 
-    return [DefaultInfo(files = sources)]
+    return [
+        DefaultInfo(files = sources),
+        LinkerPackageMappingInfo(mappings = mappings),
+    ]
 
 """
   Rule that collects declared JavaScript module output files from a list of dependencies
@@ -57,12 +73,32 @@ extract_js_module_output = rule(
     attrs = {
         "deps": attr.label_list(
             allow_files = True,
+            aspects = [module_mappings_aspect, node_modules_aspect],
         ),
         "provider": attr.string(
             doc = "JavaScript module info provider that is used for collecting sources from the dependencies.",
             mandatory = True,
             values = ["JSModuleInfo", "JSNamedModuleInfo", "JSEcmaScriptModuleInfo"],
         ),
+        "forward_linker_mappings": attr.bool(
+            mandatory = True,
+            doc = """
+              Whether linker mappings of the dependencies should be forwarded.
+
+              This can be useful when the sources are put into JavaScript consuming rules
+              where module mappings are relevant. e.g. when passed as `deps` to `esbuild`.
+            """,
+        ),
+        "include_external_npm_packages": attr.bool(
+            mandatory = True,
+            doc = """
+              Whether external NPM package sources should be extracted as well.
+
+              NPM packages can contain arbitrary sources that would be included. e.g. a
+              package could also contain `.json` files that would be extracted here. Also
+              note that there is no separation of the JS-based providers for external packages,
+            """,
+        ),
         "include_declarations": attr.bool(
             mandatory = True,
             doc = "Whether declaration files should be collected from the dependencies.",