build: bring in local packages properly during turbo prune

During turbo prune, turbo brings in the necessary local package dirs,
and figures out the pruned package.json needed. We would need to also
bring along the package dependency js files somehow which turbo doesn't
seem to handle internally for local packages.

This PR is to explitly copy these local package files across during the
build_node_modules step after turbo prune.

Future improvements:
- figure how to simply do this directly with turbo and local packages

toolchains/workspace-pnpm/build_node_modules.py

@@ -9,6 +9,23 @@
 import sys
 import tempfile
 
+def copy_dir_except_node_modules(src, dst):
+    """
+    Copy all directories, subdirectories, and files from 'src' to 'dst',
+    excluding any 'node_modules' directories.
+    """
+    for root, dirs, files in os.walk(src):
+        if 'node_modules' in dirs:
+            dirs.remove('node_modules')
+
+        for file in files:
+            src_path = os.path.join(root, file)
+            dst_path = os.path.join(dst, os.path.relpath(src_path, src))
+
+            os.makedirs(os.path.dirname(dst_path), exist_ok=True)
+            shutil.copy2(src_path, dst_path)
+
+
 if __name__ == "__main__":
     parser = argparse.ArgumentParser(description=__doc__)
     parser.add_argument(
@@ -25,6 +42,10 @@
         action="store_true",
         help="Only install production node modules",
     )
+    parser.add_argument(
+        "--local-packages-path",
+        help="Path to vendored npm package dependencies",
+    )
     parser.add_argument(
         "out_path",
         help="Path to output tree of `node_modules`",
@@ -65,6 +86,11 @@
             print(f"Failed to successfully run: {turbo_cmd}")
             sys.exit(1)
 
+        if args.local_packages_path:
+            copy_dir_except_node_modules(
+                os.path.join(tempdir, "full", args.local_packages_path),
+                os.path.join(tempdir, "json", args.local_packages_path),
+            )
         shutil.copy(
             os.path.join(tempdir, "pnpm-lock.yaml"),
             os.path.join(tempdir, "json", "pnpm-lock.yaml"),

toolchains/workspace-pnpm/macros.bzl

@@ -153,6 +153,10 @@ def build_node_modules_impl(ctx: AnalysisContext) -> list[DefaultInfo]:
         cmd.add("--prod-only")
         identifier += "--prod "
 
+    if ctx.attrs.local_packages:
+        cmd.add("--local-packages-path")
+        cmd.add(ctx.attrs.local_packages)
+
     cmd.add(out.as_output())
     cmd.hidden([ctx.attrs.workspace])
 
@@ -176,6 +180,10 @@ build_node_modules = rule(
             default = False,
             doc = "Only install production dependencies"
         ),
+        "local_packages": attrs.string(
+            default = "lib",
+            doc = """NPM vendored dependencies directory""",
+        ),
         "_python_toolchain": attrs.toolchain_dep(
             default = "toolchains//:python",
             providers = [PythonToolchainInfo],