Work around internal FB transform require() issue

scripts/rollup/build.js

@@ -10,6 +10,7 @@ const replace = require('rollup-plugin-replace');
 const chalk = require('chalk');
 const boxen = require('boxen');
 const { resolve } = require('path');
+const fixHasteImports = require('./fixHasteImports');
 const {
   createModuleMap,
   getExternalModules,
@@ -181,6 +182,8 @@ function getPlugins(entry, babelOpts, paths, filename, bundleType) {
         stripEnvVariables(false)
       )
     );
+  } else if (bundleType === bundleTypes.FB) {
+    plugins.push(fixHasteImports());
   }
   // this needs to come last or it doesn't report sizes correctly
   plugins.push(

scripts/rollup/fixHasteImports.js

@@ -0,0 +1,51 @@
+const { transform } = require('babel-core');
+
+// This makes sure top-level requires() are bound
+// to variable names matching the module names.
+// This is necessary to stop FB internal require
+// transform from complaining.
+function fixImportsTransform(babel) {
+  const { types: t } = babel;
+  return {
+    visitor: {
+      Program(path) {
+        const topLevelVars = path.node.body.filter(node =>
+          node.type === 'VariableDeclaration' &&
+          node.declarations.length === 1 &&
+          node.declarations[0].init &&
+          node.declarations[0].init.type === 'CallExpression' &&
+          node.declarations[0].init.callee.name === 'require'
+        );
+        topLevelVars.forEach(v => {
+          let moduleName = v.declarations[0].init.arguments[0].value;
+          const slashIndex = moduleName.lastIndexOf('/');
+          if (slashIndex !== -1) {
+            moduleName = moduleName.slice(slashIndex + 1);
+          }
+          const name = v.declarations[0].id.name;
+          if (moduleName === name) {
+            return;
+          }
+          // Names don't match. This means Rollup
+          // already uses this name for another variable
+          // in the global scope. Swap them so that declaration
+          // matches the module name.
+          path.scope.rename(moduleName);
+          path.scope.rename(name, moduleName);
+        });
+      },
+    },
+  };
+}
+
+module.exports = function fixHasteImports() {
+  return {
+    name: 'fix-haste-imports',
+    transformBundle(code) {
+      return transform(code, {
+        compact: false,
+        plugins: [fixImportsTransform],
+      });
+    },
+  };
+};