From 911529fd364eb3ee1b8ecdc568a9fcf38a8b55ca Mon Sep 17 00:00:00 2001
From: Rene Buchmayer <skaillzsupp@gmail.com>
Date: Tue, 11 May 2021 21:35:11 +0200
Subject: [PATCH] feat(builtin): allow bundling ESM output with the pkg_npm
 rule (#2648)

---
 internal/pkg_npm/pkg_npm.bzl          | 12 ++++++++++--
 internal/pkg_npm/test/pkg_npm.spec.js |  3 +++
 2 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/internal/pkg_npm/pkg_npm.bzl b/internal/pkg_npm/pkg_npm.bzl
index 7a84d38145..a4737ef048 100644
--- a/internal/pkg_npm/pkg_npm.bzl
+++ b/internal/pkg_npm/pkg_npm.bzl
@@ -6,7 +6,7 @@ If all users of your library code use Bazel, they should just add your library
 to the `deps` of one of their targets.
 """
 
-load("//:providers.bzl", "DeclarationInfo", "JSModuleInfo", "LinkablePackageInfo", "NODE_CONTEXT_ATTRS", "NodeContextInfo")
+load("//:providers.bzl", "DeclarationInfo", "JSEcmaScriptModuleInfo", "JSModuleInfo", "JSNamedModuleInfo", "LinkablePackageInfo", "NODE_CONTEXT_ATTRS", "NodeContextInfo")
 
 _DOC = """The pkg_npm rule creates a directory containing a publishable npm artifact.
 
@@ -299,7 +299,15 @@ def _pkg_npm(ctx):
         if JSModuleInfo in dep:
             deps_files_depsets.append(dep[JSModuleInfo].sources)
 
-        # Include all transitive declerations
+        # All direct and transitive deps that produce CommonJS modules
+        if JSNamedModuleInfo in dep:
+            deps_files_depsets.append(dep[JSNamedModuleInfo].sources)
+
+        # All direct and transitive deps that produce ES6 modules
+        if JSEcmaScriptModuleInfo in dep:
+            deps_files_depsets.append(dep[JSEcmaScriptModuleInfo].sources)
+
+        # Include all transitive declarations
         if DeclarationInfo in dep:
             deps_files_depsets.append(dep[DeclarationInfo].transitive_declarations)
 
diff --git a/internal/pkg_npm/test/pkg_npm.spec.js b/internal/pkg_npm/test/pkg_npm.spec.js
index bcc22da6b0..2fa978e178 100644
--- a/internal/pkg_npm/test/pkg_npm.spec.js
+++ b/internal/pkg_npm/test/pkg_npm.spec.js
@@ -39,6 +39,9 @@ describe('pkg_npm', () => {
   it('copies declaration files from ts_library', () => {
     expect(readFromPkg('foo.d.ts')).toContain('export declare const a: string;');
   });
+  it('copies ESM files from ts_library', () => {
+    expect(readFromPkg('foo.mjs')).toContain('export const a = \'\';');
+  });
   it('copies data dependencies', () => {
     expect(readFromPkg('data.json')).toEqual('[]');
   });