Codegen Buck: fork schema generator target for FB vs OSS via rn_codegen_cli()

Summary:
Introduced a helper macro `rn_codegen_cli()` that defines ":write_to_json" and ":rn_codegen" targets differently based on the environment. When run at FB, it uses FB-specific setup. When run in OSS as a standalone repo, we use `yarn install` and `yarn run build` directly, then use `node` to run the output CLI.

This way, the same target can be used in both environments on other Buck targets.

Motivation: we need this to define rn_codegen_modules() to use codegen to produce Java TurboModule specs, that can be built by CircleCI (we build ReactAndroid via Buck as well). That way we can finally removed the checked-in .java spec files.

Changelog: [Internal]

Reviewed By: hramos

Differential Revision: D24442468

fbshipit-source-id: b1e5fce275100cfe3a1b3ae6d61c1c6d4b25651b

packages/react-native-codegen/BUCK

@@ -1,7 +1,9 @@
 load("//tools/build_defs:fb_native_wrapper.bzl", "fb_native")
 load("//tools/build_defs/oss:rn_defs.bzl", "ANDROID", "APPLE", "IOS", "IS_OSS_BUILD", "react_native_root_target", "react_native_target", "rn_android_library", "rn_xplat_cxx_library")
 load("//tools/build_defs/third_party:yarn_defs.bzl", "yarn_workspace")
-load(":DEFS.bzl", "rn_codegen_components", "rn_codegen_modules")
+load(":DEFS.bzl", "rn_codegen_cli", "rn_codegen_components", "rn_codegen_modules")
+
+rn_codegen_cli()
 
 SETUP_ENV_DEPS = [] if IS_OSS_BUILD else [
     "//xplat/js:setup_env",
@@ -23,32 +25,6 @@ fb_native.sh_test(
     visibility = ["PUBLIC"],
 )
 
-fb_native.sh_binary(
-    name = "write_to_json",
-    main = "src/cli/combine/combine_js_to_schema.sh",
-    resources = [
-        "src/cli/combine/combine-js-to-schema.js",
-        "src/cli/combine/combine_js_to_schema.sh",
-        ":yarn-workspace",
-    ] + SETUP_ENV_DEPS,
-    visibility = ["PUBLIC"],
-)
-
-fb_native.sh_binary(
-    name = "rn_codegen",
-    main = "buck_tests/generate-tests.sh",
-    resources = glob(
-        [
-            "buck_tests/**/*.js",
-            "src/**/*.js",
-        ],
-    ) + [
-        "buck_tests/generate-tests.js",
-        "package.json",
-    ] + SETUP_ENV_DEPS,
-    visibility = ["PUBLIC"],
-)
-
 fb_native.genrule(
     name = "codegen_tests_schema",
     srcs = glob(

packages/react-native-codegen/DEFS.bzl

@@ -6,6 +6,7 @@ load(
     "APPLE",
     "CXX",
     "IOS",
+    "IS_OSS_BUILD",
     "MACOSX",
     "YOGA_CXX_TARGET",
     "fb_apple_library",
@@ -23,6 +24,87 @@ load(
     "rn_xplat_cxx_library",
 )
 
+# Call this in the react-native-codegen/BUCK file
+def rn_codegen_cli():
+    if not IS_OSS_BUILD:
+        # FB Internal Setup
+        fb_native.sh_binary(
+            name = "write_to_json",
+            main = "src/cli/combine/combine_js_to_schema.sh",
+            resources = [
+                "src/cli/combine/combine-js-to-schema.js",
+                "src/cli/combine/combine_js_to_schema.sh",
+                ":yarn-workspace",
+                "//xplat/js:setup_env",
+            ],
+            visibility = ["PUBLIC"],
+        )
+
+        fb_native.sh_binary(
+            name = "rn_codegen",
+            main = "buck_tests/generate-tests.sh",
+            resources = native.glob(
+                [
+                    "buck_tests/**/*.js",
+                    "src/**/*.js",
+                ],
+            ) + [
+                "buck_tests/generate-tests.js",
+                "package.json",
+                "//xplat/js:setup_env",
+            ],
+            visibility = ["PUBLIC"],
+        )
+    else:
+        # OSS setup, assumes yarn and node (v12.0.0+) are installed.
+        fb_native.genrule(
+            name = "setup_cli",
+            srcs = native.glob([
+                "scripts/**/*",
+                "src/**/*",
+            ], exclude = [
+                "__tests__/**/*",
+            ]) + [
+                ".babelrc",
+                ".prettierrc",
+                "package.json",
+            ],
+            out = "build",
+            bash = r"""
+                set -euo pipefail
+                mkdir -p "$OUT"
+                cp -r "$SRCDIR/" "$OUT/"
+                cd "$OUT"
+                yarn install 2> >(grep -v '^warning' 1>&2)
+                yarn run build
+            """,
+        )
+
+        fb_native.sh_binary(
+            name = "write_to_json",
+            main = "scripts/buck-oss/combine_js_to_schema.sh",
+            resources = [
+                ":setup_cli",
+            ],
+            visibility = ["PUBLIC"],
+        )
+
+        # TODO: This doesn't work yet...
+        fb_native.sh_binary(
+            name = "rn_codegen",
+            main = "buck_tests/generate-tests.sh",
+            resources = native.glob(
+                [
+                    "buck_tests/**/*.js",
+                    "src/**/*.js",
+                ],
+            ) + [
+                "buck_tests/generate-tests.js",
+                "package.json",
+            ],
+            visibility = ["PUBLIC"],
+        )
+
 def rn_codegen_modules(
         native_module_spec_name,
         name = "",

packages/react-native-codegen/scripts/buck-oss/combine_js_to_schema.sh

@@ -0,0 +1,15 @@
+#!/bin/bash
+# Copyright (c) Facebook, Inc. and its affiliates.
+#
+# This source code is licensed under the MIT license found in the
+# LICENSE file in the root directory of this source tree.
+
+# Note: To be invoked by Buck sh_binary() in OSS environment.
+# DO NOT USE outside of Buck!
+
+set -e
+set -u
+
+pushd "$BUCK_DEFAULT_RUNTIME_RESOURCES" >/dev/null
+node "build/lib/cli/combine/combine-js-to-schema-cli.js" "$@"
+popd >/dev/null