Prevent npm from ignoring .gitignore

.gitignore

@@ -11,7 +11,11 @@ npm-debug.log
 ios/
 android/
 
+# don't commit this since is auto-generated when packing or publishing
+templates/boilerplate/.npmignore
+
 # ignore these in case the app was run directly from templates/boilerplate
+# also add these to bin/prepack.js
 /templates/boilerplate/bun.lockb
 /templates/boilerplate/yarn.lock
 /templates/boilerplate/package-lock.json

bin/prepack.js

@@ -0,0 +1,37 @@
+#!/usr/bin/env node
+
+import fs from 'fs-extra';
+
+// npm will not package the .gitignore file in templates/boilerplate/.gitignore
+// by default. The solution is to create a .npmignore file that npm will use
+// instead of the .gitignore file, and tell it to include the .gitignore file.
+// We want everything in the .gitignore file to also be in the .npmignore file
+// so we can ensure we don't accidentally package files that should be ignored.
+// This script is run prior to packaging the library for npm (see package.json
+// "prepack" script) and generates the .npmignore from the .gitignore to ensure
+// they are always in sync.
+//
+// Also include any lock files or other files that shouldn't be included in the
+// .gitignore file but that we want to ensure are not packaged to npm. These
+// files can also be added to the root gitignore file to ensure they're also
+// excluded from git
+function copyGitIgnoreToNpmIgnore() {
+  const gitIgnore = './templates/boilerplate/.gitignore';
+  const npmIgnore = './templates/boilerplate/.npmignore';
+
+  fs.copySync(gitIgnore, npmIgnore);
+
+  fs.appendFileSync(
+    npmIgnore,
+    `
+// # Prevent NPM from ignoring the .gitignore file
+!.gitignore
+bun.lockb
+yarn.lock
+package-lock.json
+pnpm-lock.yaml
+`,
+  );
+}
+
+copyGitIgnoreToNpmIgnore();

package.json

@@ -2,7 +2,7 @@
   "name": "create-belt-app",
   "author": "thoughtbot, Inc.",
   "license": "MIT",
-  "version": "0.3.0",
+  "version": "0.3.1",
   "description": "React Native Expo project starter and generator CLI",
   "type": "module",
   "exports": "./dist/index.js",
@@ -19,6 +19,7 @@
     "package.json"
   ],
   "scripts": {
+    "prepack": "node ./bin/prepack.js",
     "build": "tsup",
     "dev": "tsup --watch",
     "clean": "rm -rf dist node_modules",

templates/boilerplate/.gitignore

@@ -1,5 +1,7 @@
 # Learn more https://docs.github.com/en/get-started/getting-started-with-git/ignoring-files
 
+## ATTENTION: Files ignored here must be mirrored in the sibling .npmignore file
+
 # dependencies
 node_modules/