Issue facebook#11257 - compare files/folders in package/npm to "files…

…" in package.json, only copy whitelisted files/folders to build (+1 squashed commit)

Squashed commits:
[d400198] handle directories in files list - e.g. "libs/" (+1 squashed commit)
Squashed commits:
[52a4d3b] Add in file check to make sure all entry points have equivalent files in ./npm folder.
Fail the build if any equivalent missing.

scripts/rollup/packaging.js

@@ -6,6 +6,7 @@ const join = require('path').join;
 const resolve = require('path').resolve;
 const Bundles = require('./bundles');
 const asyncCopyTo = require('./utils').asyncCopyTo;
+const glob = require('glob');
 
 const UMD_DEV = Bundles.bundleTypes.UMD_DEV;
 const UMD_PROD = Bundles.bundleTypes.UMD_PROD;
@@ -165,15 +166,47 @@ function copyNodePackageTemplate(packageName) {
     // We already created this package (e.g. due to another entry point).
     return Promise.resolve();
   }
-  // TODO: verify that all copied files are either in the "files"
-  // whitelist or implicitly published by npm.
-  return asyncCopyTo(npmFrom, to).then(() =>
-    Promise.all([
+  fs.mkdirSync(to);
+  const packageJson = resolve(`${from}/package.json`);
+  const whitelistedFiles = fs.existsSync(packageJson)
+    ? require(packageJson).files
+    : null;
+  const npmRootFiles = fs.readdirSync(npmFrom);
+  const packageRootEntries = glob.sync('*.js', {
+    cwd: from,
+  });
+  packageRootEntries.forEach(entry => {
+    // Terminate the build if any entry point in the package root does not have an equivalent in ./npm.
+    // Exceptions: *.fb.js
+    if (!npmRootFiles.includes(entry) && !/.fb.js$/.test(entry)) {
+      console.error(
+        `Entry point ${entry} in package ${packageName} does not have an equivalent in ./npm`
+      );
+      process.exit(1);
+    }
+  });
+  if (whitelistedFiles && whitelistedFiles.length > 0) {
+    let asyncCopyProxies = [];
+    asyncCopyProxies = npmRootFiles.reduce((proxies, file) => {
+      if (
+        whitelistedFiles.includes(file) ||
+        whitelistedFiles.includes(`${file}/`)
+      ) {
+        proxies.push(
+          asyncCopyTo(resolve(`${npmFrom}/${file}`), `${to}/${file}`)
+        );
+      }
+      return proxies;
+    }, asyncCopyProxies);
+    return Promise.all([
+      ...asyncCopyProxies,
       asyncCopyTo(resolve(`${from}/package.json`), `${to}/package.json`),
       asyncCopyTo(resolve(`${from}/README.md`), `${to}/README.md`),
       asyncCopyTo(resolve('./LICENSE'), `${to}/LICENSE`),
-    ])
-  );
+    ]);
+  } else {
+    return Promise.resolve();
+  }
 }
 
 function createNodePackage(bundleType, packageName, filename) {