chore(0.76): add Yarn constraints to enforce dependency alignment

.github/workflows/microsoft-pr.yml

@@ -63,3 +63,19 @@ jobs:
         run: |
           echo "Target branch: ${{ github.base_ref }}"
           yarn nx release --dry-run --verbose
+  yarn-constraints:
+    name: "Check Yarn Constraints"
+    permissions: {}
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          filter: blob:none
+          fetch-depth: 0
+      - uses: actions/setup-node@v4
+        with:
+          node-version: '22'
+      - name: Install dependencies
+        run: yarn
+      - name: Check constraints
+        run: yarn constraints

docs/Releases.md

@@ -215,3 +215,13 @@ We do this so that our first release will have a proper patch version of 0, as s
 ```
 
 </details>
+
+## Hermes Compatibility (0.74 and above)
+
+*Note: This is only applicable if Hermes is enabled (I.E: `USE_HERMES=1 pod install`.*
+
+React Native macOS updates the patch version automatically for every change that comes through, so our patch number can differ wildly from that of vanilla React Native.
+
+To ensure the best possible Hermes compatibility, we specify a peer dependency in React Native macOS's `package.json` indicating which version of upstream React Native best corresponds with our own version. For example, our 0.74.34 corresponds to upstream's 0.74.7, and we reflect this connection in [this particular version of `package.json`](https://github.com/microsoft/react-native-macos/blob/2db3abeb5d4318fee3abdff4a4d1a68967223135/packages/react-native/package.json#L103).
+
+For stable branches, the existence of this peer dependency is enforced as part of our CIs via [Yarn Constraints](https://yarnpkg.com/features/constraints).

package.json

@@ -56,6 +56,7 @@
     "@tsconfig/node18": "1.0.1",
     "@types/react": "^18.2.6",
     "@typescript-eslint/parser": "^7.1.1",
+    "@yarnpkg/types": "^4.0.1",
     "ansi-styles": "^4.2.1",
     "babel-plugin-minify-dead-code-elimination": "^0.5.2",
     "babel-plugin-syntax-hermes-parser": "0.23.1",
@@ -94,7 +95,7 @@
     "mkdirp": "^0.5.1",
     "node-fetch": "^2.2.0",
     "nullthrows": "^1.1.1",
-    "nx": "21.2.4",
+    "nx": "^21.2.4",
     "prettier": "2.8.8",
     "prettier-plugin-hermes-parser": "0.23.1",
     "react": "18.3.1",

packages/nx-release-version/package.json

@@ -1,6 +1,7 @@
 {
   "name": "@react-native-macos/nx-release-version",
   "version": "0.0.1-dev",
+  "private": true,
   "description": "Nx Release Version Actions for React Native macOS",
   "homepage": "https://github.com/microsoft/react-native-macos/tree/HEAD/packages/nx-release-version#readme",
   "license": "MIT",

packages/rn-tester/package.json

@@ -23,8 +23,8 @@
     "clean-ios": "rm -rf build/generated/ios Pods Podfile.lock"
   },
   "dependencies": {
-    "@react-native/oss-library-example": "0.76.10",
-    "@react-native/popup-menu-android": "workspace:*",
+    "@react-native/oss-library-example": "workspace:*",
+    "@react-native/popup-menu-android": "0.76.9",
     "flow-enums-runtime": "^0.0.6",
     "invariant": "^2.2.4",
     "nullthrows": "^1.1.1"

yarn.config.cjs

@@ -0,0 +1,116 @@
+// @ts-check
+
+/** @type {import('@yarnpkg/types')} */
+const {defineConfig} = require('@yarnpkg/types');
+
+/**
+ * @typedef {import('@yarnpkg/types').Yarn.Constraints.Context} Context
+ * @typedef {import('@yarnpkg/types').Yarn.Constraints.Workspace} Workspace
+ * @typedef {import('@yarnpkg/types').Yarn.Constraints.Dependency} Dependency
+ */
+
+/**
+ * Enforce that react-native-macos declares a peer dependency on react-native on release branches,
+ * except on the main branch, where there is no published version of React Native to align to.
+ * @param {Context} context
+ */
+function expectReactNativePeerDependency({Yarn}) {
+    const rnmWorkspace = Yarn.workspace({ident: 'react-native-macos'});
+    if (!rnmWorkspace) {
+        // Report error on root workspace since react-native-macos doesn't exist
+        Yarn.workspace().error('react-native-macos workspace must exist in the monorepo');
+        return;
+    }
+
+    // Check if react-native-macos version is 1000.0.0 - implying we are on the main branch
+    const isMainBranch = rnmWorkspace.manifest.version === '1000.0.0';
+    if (!isMainBranch) {
+        const rnPeerDependency = rnmWorkspace.pkg.peerDependencies.get('react-native');
+        if (!rnPeerDependency) {
+            rnmWorkspace.error('react-native-macos must declare a peer dependency on react-native on release branches');
+        }
+    }
+}
+
+/**
+ * Enforce that all @react-native/ scoped packages use the same version
+ * as the react-native peer dependency declared in react-native-macos.
+ * On the main branch, enforce that we use workspace:* for @react-native/ packages.
+ * @param {Context} context
+ */
+function enforceReactNativeVersionConsistency({Yarn}) {
+    const rnmWorkspace = Yarn.workspace({ident: 'react-native-macos'});
+    if (!rnmWorkspace) {
+        // Report error on root workspace since react-native-macos doesn't exist
+        Yarn.workspace().error('react-native-macos workspace must exist in the monorepo');
+        return;
+    }
+
+    // Check if react-native-macos version is 1000.0.0 - implying we are on the main branch
+    const isMainBranch = rnmWorkspace.manifest.version === '1000.0.0';
+
+    let targetVersion;
+    if (isMainBranch) {
+        // On main branch, use workspace:* for @react-native/ packages
+        targetVersion = 'workspace:*';
+    } else {
+        const rnPeerDependency = rnmWorkspace.pkg.peerDependencies.get('react-native');
+        if (!rnPeerDependency) {
+            rnmWorkspace.error('react-native-macos must declare a peer dependency on react-native on release branches');
+            return;
+        }
+        targetVersion = rnPeerDependency;
+    }    // Enforce this version on all @react-native/ scoped packages across all workspaces
+    for (const dependency of Yarn.dependencies()) {
+        if (dependency.ident.startsWith('@react-native/')) {
+            // Check if the target package is private (not published)
+            const targetWorkspace = Yarn.workspace({ident: dependency.ident});
+            const isPrivatePackage = targetWorkspace && targetWorkspace.manifest.private;
+
+            if (isPrivatePackage) {
+                // Private packages should always use workspace:* since they're not published
+                dependency.update('workspace:*');
+            } else {
+                dependency.update(targetVersion);
+            }
+        }
+    }
+}
+
+/**
+ * Enforce that all @react-native-macos/ scoped packages use the same version
+ * as react-native-macos, but only for non-private packages.
+ * @param {Context} context
+ */
+function enforceReactNativeMacosVersionConsistency({Yarn}) {
+    const rnmWorkspace = Yarn.workspace({ident: 'react-native-macos'});
+    if (!rnmWorkspace) {
+        // Report error on root workspace since react-native-macos doesn't exist
+        Yarn.workspace().error('react-native-macos workspace must exist in the monorepo');
+        return;
+    }
+
+    const targetVersion = rnmWorkspace.manifest.version;
+    if (!targetVersion) {
+        rnmWorkspace.error('react-native-macos must have a version');
+        return;
+    }
+
+    // Enforce this version on all non-private @react-native-macos/ scoped packages
+    for (const workspace of Yarn.workspaces()) {
+        const isReactNativeMacosScoped = workspace.ident && workspace.ident.startsWith('@react-native-macos/');
+        const isPrivate = workspace.manifest.private;
+
+        if (isReactNativeMacosScoped && !isPrivate) {
+            workspace.set('version', targetVersion);
+        }
+    }
+}
+
+module.exports = defineConfig({
+  constraints: async ctx => {
+    expectReactNativePeerDependency(ctx);
+    enforceReactNativeVersionConsistency(ctx);
+    enforceReactNativeMacosVersionConsistency(ctx);
+  },
+});