Run yarn install in action

.bazelversion

@@ -1 +1 @@
-7.0.0rc6
+7.0.2

e2e/bazel_7_litmus/.bazelversion

@@ -0,0 +1 @@
+7.0.2

e2e/bazel_6_litmus/MODULE.bazel → e2e/bazel_7_litmus/MODULE.bazel

@@ -1,5 +1,5 @@
 module(
-    name = "bazel_6_litmus",
+    name = "bazel_7_litmus",
     version = "0.0.0",
     compatibility_level = 0,
 )

e2e/bazel_7_litmus_workspace/.bazelversion

@@ -0,0 +1 @@
+7.0.2

lib/private/extensions/node_modules.bzl

@@ -2,14 +2,13 @@
 `node_modules` module extension implementation.
 """
 
-load("//lib/private:repositories.bzl", "yarn_install", "YARN_INSTALL_ATTRS")
+load("//lib/private:repositories.bzl", "yarn_install", "yarn_install_via_action", "YARN_INSTALL_ATTRS")
 
 visibility(["//lib/private"])
 
 def _node_modules_impl(mctx):
     root_modules = []
     for mod in mctx.modules:
-        # TODO Use mod.is_root to detect root module and include in returns
         for attrs in mod.tags.yarn:
             if mod.is_root:
                 root_modules.append(attrs.name)
@@ -31,6 +30,18 @@ def _node_modules_impl(mctx):
                 host_node_bin = attrs.host_node_bin,
                 host_yarn_bin = attrs.host_yarn_bin,
             )
+        for attrs in mod.tags.yarn_via_action:
+            if mod.is_root:
+                root_modules.append(attrs.name)
+            yarn_install_via_action(
+                name = attrs.name,
+                package_json = attrs.package_json,
+                yarn_lock = attrs.yarn_lock,
+                package_path = attrs.package_path,
+                host_node_bin = attrs.host_node_bin,
+                data = attrs.data,
+                quiet = attrs.quiet,
+            )
 
     return mctx.extension_metadata(
         root_module_direct_deps = root_modules,
@@ -47,7 +58,43 @@ node_modules = module_extension(
                 ),
             }),
             doc = "",
-        )
+        ),
+        # The Plan
+        # 
+        # 1. Repo rule parses package.json and yarn.lock
+        # 2. Repo rule generates `BUILD.bazel` file that calls `yarn_install_via_action`
+        #    This is done so that outputs go to the same directory as the `yarn_install` repo rule.
+        # 3. Existing interface is preserved, work is just deferred to exec stage.
+        "yarn_via_action": tag_class(
+            attrs = {
+                "name": attr.string(
+                    mandatory = True,
+                ),
+                "package_json": attr.label(
+                    allow_single_file = True,
+                    mandatory = True,
+                ),
+                "yarn_lock": attr.label(
+                    allow_single_file = True,
+                    mandatory = True,
+                ),
+                "package_path": attr.string(
+                    mandatory = True,
+                ),
+                "host_node_bin": attr.label(
+                    allow_single_file = True,
+                    mandatory = True,
+                ),
+                "data": attr.label(
+                    allow_files = True,
+                ),
+                "quiet": attr.bool(
+                    default = True,
+                    doc = "Hides output, except in the event of install failure.",
+                ),
+            },
+            doc = "",
+        ),
     },
     doc = "",
 )

lib/private/repositories.bzl

@@ -7,11 +7,13 @@ load("//lib/private:repositories/nodejs_toolchain_configure/impl.bzl", _nodejs_t
 load("//lib/private:repositories/nodejs_toolchains.bzl", _nodejs_toolchains = "nodejs_toolchains")
 load("//lib/private:repositories/yarn_install/attrs.bzl", _YARN_INSTALL_ATTRS = "YARN_INSTALL_ATTRS")
 load("//lib/private:repositories/yarn_install/impl.bzl", _yarn_install = "yarn_install")
+load("//lib/private:repositories/yarn_install_via_action/impl.bzl", _yarn_install_via_action = "yarn_install_via_action")
 
 visibility(["//", "//lib"])
 
 YARN_INSTALL_ATTRS = _YARN_INSTALL_ATTRS
 yarn_install = _yarn_install
+yarn_install_via_action = _yarn_install_via_action
 nodejs_download = _nodejs_download
 nodejs_download_host = _nodejs_download_host
 nodejs_toolchain_configure = _nodejs_toolchain_configure

lib/private/repositories/yarn_install_via_action/impl.bzl

@@ -0,0 +1,52 @@
+"""
+"""
+
+visibility(["//lib/private"])
+
+def _impl(rctx):
+    pass
+    # 1. Resolve `package.json` and `yarn.lock` paths.
+
+    # 2. Process in their original location using API from forked Yarn.
+
+    # 3. Using data from `hoisted` API, generate `BUILD.bazel` file.
+    #    Required targets to match existing API follow.
+    #    - `:node_modules`, catch-all target that includes all dependencies.
+    #      Rule type: `js_library`.
+    #    - `:node_modules/{package_name}`, an alias that allows a subset of outputs to be referenced.
+    #      Rule type: NA, source files.
+    #    - `[{package_scope}/]{package_name}:{package_name}`, normal way packages are referenced
+    #      Rule type: `js_library`.
+    #    - `[{package_scope}/]{package_name}:{package_name}__contents`, implementation detail.
+    #      Rule type: `js_library`.
+    #    - `[{package_scope}/]{package_name}:{package_name}__files`, implementation detail.
+    #      Rule type: `filegroup`.
+    #    - `[{package_scope}/]{package_name}:{package_name}__typings`, implementation detail.
+    #      Rule type: `alias`.
+    #    - `[{package_scope}/]{package_name}:{package_name}__umd`, implementation detail, unused.
+    #      Rule type: `npm_umd_bundle`.
+    #    - `[{package_scope}/]{package_name}:{package_name}__umd_directory_file_path`, implementation detail, unused.
+    #      Rule type: `directory_file_path`.
+
+yarn_install_via_action = repository_rule(
+    implementation = _impl,
+    attrs = {
+        "package_json": attr.label(
+            mandatory = True,
+            allow_single_file = True,
+        ),
+        "yarn_lock": attr.label(
+            mandatory = True,
+            allow_single_file = True,
+        ),
+        "host_node_bin": attr.label(
+            mandatory = True,
+            allow_single_file = True,
+        ),
+    },
+    doc = """
+        Parses `package.json` and `yarn.lock`, extracting data required for the `yarn_install` rule.
+
+        The result is similar to the `yarn_install` repository rule when operating in directory mode.
+    """,
+)