docs(metro-serializer-esbuild): metro-serializer-esbuild requires Metro 0.66.1 (#383)

change/@rnx-kit-metro-config-05f48157-e429-49ec-9f0a-f2cf3100279c.json

@@ -0,0 +1,7 @@
+{
+  "type": "none",
+  "comment": "Updated READMEs to mention that metro-serializer-esbuild requires Metro 0.66.1",
+  "packageName": "@rnx-kit/metro-config",
+  "email": "4123478+tido64@users.noreply.github.com",
+  "dependentChangeType": "none"
+}

change/@rnx-kit-metro-serializer-esbuild-93f281ef-bf67-46b6-a555-278c6b610013.json

@@ -0,0 +1,7 @@
+{
+  "type": "none",
+  "comment": "Updated READMEs to mention that metro-serializer-esbuild requires Metro 0.66.1",
+  "packageName": "@rnx-kit/metro-serializer-esbuild",
+  "email": "4123478+tido64@users.noreply.github.com",
+  "dependentChangeType": "none"
+}

packages/metro-config/README.md

@@ -83,8 +83,8 @@ will come with such helpers.
 If you're feeling adventurous, you can try an experimental Metro serializer
 we've built that adds support for tree shaking:
 [@rnx-kit/metro-serializer-esbuild](https://github.com/microsoft/rnx-kit/tree/main/packages/metro-serializer-esbuild#readme).
-Do note that you will need to be on React Native 0.64 or above, and use an as
-yet unreleased version of Metro.
+Do note that you will need to be on React Native 0.64 or above, and use Metro
+0.66.1.
 
 ### Plugins
 

packages/metro-serializer-esbuild/README.md

@@ -1,6 +1,7 @@
 # @rnx-kit/metro-serializer-esbuild
 
 [![Build](https://github.com/microsoft/rnx-kit/actions/workflows/build.yml/badge.svg)](https://github.com/microsoft/rnx-kit/actions/workflows/build.yml)
+![This plugin is highly experimental](https://img.shields.io/badge/state-experimental-critical)
 [![npm version](https://img.shields.io/npm/v/@rnx-kit/metro-serializer-esbuild)](https://www.npmjs.com/package/@rnx-kit/metro-serializer-esbuild)
 
 ⚠️ **THIS PLUGIN IS HIGHLY EXPERIMENTAL** ⚠️
@@ -8,14 +9,31 @@
 Allow Metro to use [esbuild](https://esbuild.github.io) for bundling and
 serialization.
 
+## Motivation
+
+Metro currently does not implement tree shaking, i.e. it does not attempt to
+remove unused code from the JS bundle. For instance, given this code snippet:
+
+```ts
+import { partition } from "lodash";
+```
+
+Metro will bundle all of `lodash` in your bundle even though you're only using a
+small part of it. In `lodash`'s case, you can add
+[`babel-plugin-lodash`](https://github.com/lodash/babel-plugin-lodash#readme) to
+your Babel config to help Metro strip away some modules, but not all libraries
+will come with such helpers. For more details, see issues
+[#227](https://github.com/facebook/metro/issues/227) and
+[#632](https://github.com/facebook/metro/issues/632).
+
+metro-serializer-esbuild addresses this by letting esbuild take over bundling.
+
 ## Requirements
 
-This plugin currently depends on some unstable features in an as yet unreleased
-version of Metro. The following features are presumed to exist in some form in
-0.67 (or later), but no guarantees are made.
-
-- [`transformer.unstable_disableModuleWrapping`](https://github.com/facebook/metro/commit/598de6f537f4d7286cee89094bcdb7101e8e4f17)
-- [`transformer.unstable_disableNormalizePseudoGlobals`](https://github.com/facebook/metro/commit/5b913fa0cd30ce5b90e2b1f6318454fbdd170708)
+This plugin currently depends on some unstable features introduced in Metro
+[0.66.1](https://github.com/facebook/metro/releases/tag/v0.66.1). Breaking
+changes were introduced in Metro 0.60, so this plugin will not work with React
+Native below 0.64.
 
 ## Usage