Remove .npmignore files from other packages, add lint check (#50786)

Summary:
Pull Request resolved: #50786

Follows #50784. Having any `.npmignore` files is a gotcha — remove and replace with `package.json#files`.

Changelog: [Internal]

Reviewed By: cortinico

Differential Revision: D73193257

fbshipit-source-id: de715d74195e4f53c817c11f244a61c79b8ce5bc

Author: huntie

.github/actions/lint/action.yml

@@ -29,6 +29,9 @@ runs:
     - name: Lint java
       shell: bash
       run: ./.github/workflow-scripts/exec_swallow_error.sh yarn lint-java --check
+    - name: Lint file structure
+      shell: bash
+      run: ./.github/workflow-scripts/lint_files.sh
     - name: Verify not committing repo after running build
       shell: bash
       run: yarn run build --check

.github/workflow-scripts/lint_files.sh

@@ -0,0 +1,12 @@
+#!/bin/bash
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+#
+# This source code is licensed under the MIT license found in the
+# LICENSE file in the root directory of this source tree.
+
+set -e
+
+if git ls-files | grep -E '\.npmignore$'; then
+  echo "Error: Found unexpected .npmignore file(s). Please use package.json#files instead."
+  exit 1
+fi

packages/assets/.npmignore

@@ -18,5 +18,14 @@
   "bugs": "https://github.com/facebook/react-native/issues",
   "engines": {
     "node": ">=18"
-  }
+  },
+  "files": [
+    "path-support.js",
+    "registry.js",
+    "README.md",
+    "!**/__docs__/**",
+    "!**/__fixtures__/**",
+    "!**/__mocks__/**",
+    "!**/__tests__/**"
+  ]
 }

packages/assets/package.json

@@ -15,5 +15,13 @@
     "normalize-colors",
     "react-native"
   ],
-  "bugs": "https://github.com/facebook/react-native/issues"
+  "bugs": "https://github.com/facebook/react-native/issues",
+  "files": [
+    "index.js",
+    "README.md",
+    "!**/__docs__/**",
+    "!**/__fixtures__/**",
+    "!**/__mocks__/**",
+    "!**/__tests__/**"
+  ]
 }

packages/normalize-color/.npmignore

@@ -19,5 +19,15 @@
   "bugs": "https://github.com/facebook/react-native/issues",
   "engines": {
     "node": ">=18"
-  }
+  },
+  "files": [
+    "console.js",
+    "error-guard.js",
+    "index.js",
+    "README.md",
+    "!**/__docs__/**",
+    "!**/__fixtures__/**",
+    "!**/__mocks__/**",
+    "!**/__tests__/**"
+  ]
 }

packages/normalize-color/package.json

@@ -2,7 +2,6 @@
   "name": "@react-native/babel-preset",
   "version": "0.80.0-main",
   "description": "Babel preset for React Native applications",
-  "main": "src/index.js",
   "repository": {
     "type": "git",
     "url": "git+ssh://git@github.com/facebook/react-native.git"
@@ -13,6 +12,18 @@
     "react-native"
   ],
   "license": "MIT",
+  "engines": {
+    "node": ">=18"
+  },
+  "main": "src/index.js",
+  "files": [
+    "src",
+    "README.md",
+    "!**/__docs__/**",
+    "!**/__fixtures__/**",
+    "!**/__mocks__/**",
+    "!**/__tests__/**"
+  ],
   "dependencies": {
     "@babel/core": "^7.25.2",
     "@babel/plugin-proposal-export-default-from": "^7.24.7",
@@ -62,8 +73,5 @@
   },
   "peerDependencies": {
     "@babel/core": "*"
-  },
-  "engines": {
-    "node": ">=18"
   }
 }

packages/polyfills/.npmignore

@@ -2,7 +2,6 @@
   "name": "@react-native/metro-babel-transformer",
   "version": "0.80.0-main",
   "description": "Babel transformer for React Native applications.",
-  "main": "src/index.js",
   "repository": {
     "type": "git",
     "url": "git+ssh://git@github.com/facebook/react-native.git",
@@ -14,6 +13,18 @@
     "metro"
   ],
   "license": "MIT",
+  "engines": {
+    "node": ">=18"
+  },
+  "main": "src/index.js",
+  "files": [
+    "src",
+    "README.md",
+    "!**/__docs__/**",
+    "!**/__fixtures__/**",
+    "!**/__mocks__/**",
+    "!**/__tests__/**"
+  ],
   "dependencies": {
     "@babel/core": "^7.25.2",
     "@react-native/babel-preset": "0.80.0-main",
@@ -22,8 +33,5 @@
   },
   "peerDependencies": {
     "@babel/core": "*"
-  },
-  "engines": {
-    "node": ">=18"
   }
 }

packages/polyfills/package.json

@@ -3,10 +3,6 @@
   "version": "0.80.0-main",
   "description": "Virtualized lists for React Native.",
   "license": "MIT",
-  "exports": {
-    ".": "./index.js",
-    "./package.json": "./package.json"
-  },
   "repository": {
     "type": "git",
     "url": "git+https://github.com/facebook/react-native.git",
@@ -23,6 +19,21 @@
   "engines": {
     "node": ">=18"
   },
+  "exports": {
+    ".": "./index.js",
+    "./package.json": "./package.json"
+  },
+  "files": [
+    "index.js",
+    "index.d.ts",
+    "Lists",
+    "README.md",
+    "Utilities",
+    "!**/__docs__/**",
+    "!**/__fixtures__/**",
+    "!**/__mocks__/**",
+    "!**/__tests__/**"
+  ],
   "dependencies": {
     "invariant": "^2.2.4",
     "nullthrows": "^1.1.1"