Viewing github.com/facebook/react/scripts/rollup/wrappers.js

```
'use strict';
```
```
const {resolve} = require('path');
```
```
const {readFileSync} = require('fs');
```

const {signFile, getSigningToken} = require('signedsource');

const {bundleTypes, moduleTypes} = require('./bundles');

```
const {
```
```
  NODE_ES2015,
```
```
  ESM_DEV,
```
```
  ESM_PROD,
```
```
  UMD_DEV,
```
```
  UMD_PROD,
```
```
  UMD_PROFILING,
```
```
  NODE_DEV,
```
```
  NODE_PROD,
```
```
  NODE_PROFILING,
```
```
  BUN_DEV,
```
```
  BUN_PROD,
```
```
  FB_WWW_DEV,
```
```
  FB_WWW_PROD,
```
```
  FB_WWW_PROFILING,
```
```
  RN_OSS_DEV,
```
```
  RN_OSS_PROD,
```
```
  RN_OSS_PROFILING,
```
```
  RN_FB_DEV,
```
```
  RN_FB_PROD,
```
```
  RN_FB_PROFILING,
```
```
  BROWSER_SCRIPT,
```
```
} = bundleTypes;
```
```
const {RECONCILER} = moduleTypes;
```

const USE_STRICT_HEADER_REGEX = /'use strict';\n+/;

function registerInternalModuleStart(globalName) {

  const path = resolve(__dirname, 'wrappers', 'registerInternalModuleBegin.js');

```
  const file = readFileSync(path);
```
```
  return String(file).trim();
```
```
}
```

function registerInternalModuleStop(globalName) {

  const path = resolve(__dirname, 'wrappers', 'registerInternalModuleEnd.js');

```
  const file = readFileSync(path);
```

  // Remove the 'use strict' directive from the footer.

  // This directive is only meaningful when it is the first statement in a file or function.

  return String(file).replace(USE_STRICT_HEADER_REGEX, '').trim();

```
}
```

const license = ` * 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.`;

```
const wrappers = {
```

  /***************** NODE_ES2015 *****************/

  [NODE_ES2015](source, globalName, filename, moduleType) {

```
    return `/**
```
```
 * @license React
```
```
 * ${filename}
```
```
 *
```
```
${license}
```
```
 */
```
```
'use strict';
```
```
${source}`;
```
```
  },
```

  /***************** ESM_DEV *****************/

  [ESM_DEV](source, globalName, filename, moduleType) {

```
    return `/**
```
```
* @license React
```
```
 * ${filename}
```
```
 *
```
```
${license}
```
```
 */
```
```
${source}`;
```
```
  },
```

  /***************** ESM_PROD *****************/

  [ESM_PROD](source, globalName, filename, moduleType) {

```
    return `/**
```
```
* @license React
```
```
 * ${filename}
```
```
 *
```
```
${license}
```
```
 */
```
```
${source}`;
```
```
  },
```

  /***************** BUN_DEV *****************/

  [BUN_DEV](source, globalName, filename, moduleType) {

```
    return `/**
```
```
* @license React
```
```
 * ${filename}
```
```
 *
```
```
${license}
```
```
 */
```
```
${source}`;
```
```
  },
```

  /***************** BUN_PROD *****************/

  [BUN_PROD](source, globalName, filename, moduleType) {

```
    return `/**
```
```
* @license React
```
```
 * ${filename}
```
```
 *
```
```
${license}
```
```
 */
```
```
${source}`;
```
```
  },
```

  /***************** UMD_DEV *****************/

  [UMD_DEV](source, globalName, filename, moduleType) {

```
    return `/**
```
```
 * @license React
```
```
 * ${filename}
```
```
 *
```
```
${license}
```
```
 */
```
```
${source}`;
```
```
  },
```

  /***************** UMD_PROD *****************/

  [UMD_PROD](source, globalName, filename, moduleType) {

```
    return `/**
```
```
 * @license React
```
```
 * ${filename}
```
```
 *
```
```
${license}
```
```
 */
```
```
(function(){${source}})();`;
```
```
  },
```

  /***************** UMD_PROFILING *****************/

  [UMD_PROFILING](source, globalName, filename, moduleType) {

```
    return `/**
```
```
 * @license React
```
```
 * ${filename}
```
```
 *
```
```
${license}
```
```
 */
```
```
(function(){${source}})();`;
```
```
  },
```

  /***************** NODE_DEV *****************/

  [NODE_DEV](source, globalName, filename, moduleType) {

```
    return `/**
```
```
 * @license React
```
```
 * ${filename}
```
```
 *
```
```
${license}
```
```
 */
```
```
'use strict';
```

if (process.env.NODE_ENV !== "production") {

```
  (function() {
```
```
${source}
```
```
  })();
```
```
}`;
```
```
  },
```

  /***************** NODE_PROD *****************/

  [NODE_PROD](source, globalName, filename, moduleType) {

```
    return `/**
```
```
 * @license React
```
```
 * ${filename}
```
```
 *
```
```
${license}
```
```
 */
```
```
${source}`;
```
```
  },
```

  /***************** NODE_PROFILING *****************/

  [NODE_PROFILING](source, globalName, filename, moduleType) {

```
    return `/**
```
```
 * @license React
```
```
 * ${filename}
```
```
 *
```
```
${license}
```
```
 */
```
```
${source}`;
```
```
  },
```

  /****************** FB_WWW_DEV ******************/

  [FB_WWW_DEV](source, globalName, filename, moduleType) {

```
    return `/**
```
```
${license}
```
```
 *
```
```
 * @noflow
```
```
 * @nolint
```
```
 * @preventMunge
```
```
 * @preserve-invariant-messages
```
```
 */
```
```
'use strict';
```
```
if (__DEV__) {
```
```
  (function() {
```
```
${source}
```
```
  })();
```
```
}`;
```
```
  },
```

  /****************** FB_WWW_PROD ******************/

  [FB_WWW_PROD](source, globalName, filename, moduleType) {

```
    return `/**
```
```
${license}
```
```
 *
```
```
 * @noflow
```
```
 * @nolint
```
```
 * @preventMunge
```
```
 * @preserve-invariant-messages
```
```
 */
```
```
${source}`;
```
```
  },
```

  /****************** FB_WWW_PROFILING ******************/

  [FB_WWW_PROFILING](source, globalName, filename, moduleType) {

```
    return `/**
```
```
${license}
```
```
 *
```
```
 * @noflow
```
```
 * @nolint
```
```
 * @preventMunge
```
```
 * @preserve-invariant-messages
```
```
 */
```
```
${source}`;
```
```
  },
```

  /****************** RN_OSS_DEV ******************/

  [RN_OSS_DEV](source, globalName, filename, moduleType) {

```
    return signFile(`/**
```
```
${license}
```
```
 *
```
```
 * @noflow
```
```
 * @nolint
```
```
 * @providesModule ${globalName}-dev
```
```
 * @preventMunge
```
```
 * ${getSigningToken()}
```
```
 */
```
```
'use strict';
```
```
if (__DEV__) {
```
```
  (function() {
```
```
${source}
```
```
  })();
```
```
}`);
```
```
  },
```

  /****************** RN_OSS_PROD ******************/

  [RN_OSS_PROD](source, globalName, filename, moduleType) {

```
    return signFile(`/**
```
```
${license}
```
```
 *
```
```
 * @noflow
```
```
 * @nolint
```
```
 * @providesModule ${globalName}-prod
```
```
 * @preventMunge
```
```
 * ${getSigningToken()}
```
```
 */
```
```
${source}`);
```
```
  },
```

  /****************** RN_OSS_PROFILING ******************/

  [RN_OSS_PROFILING](source, globalName, filename, moduleType) {

```
    return signFile(`/**
```
```
${license}
```
```
 *
```
```
 * @noflow
```
```
 * @nolint
```

 * @providesModule ${globalName}-profiling

```
 * @preventMunge
```
```
 * ${getSigningToken()}
```
```
 */
```
```
${source}`);
```
```
  },
```

  /****************** RN_FB_DEV ******************/

  [RN_FB_DEV](source, globalName, filename, moduleType) {

```
    return signFile(`/**
```
```
${license}
```
```
 *
```
```
 * @noflow
```
```
 * @nolint
```
```
 * @preventMunge
```
```
 * ${getSigningToken()}
```
```
 */
```
```
'use strict';
```
```
if (__DEV__) {
```
```
  (function() {
```
```
${source}
```
```
  })();
```
```
}`);
```
```
  },
```

  /****************** RN_FB_PROD ******************/

  [RN_FB_PROD](source, globalName, filename, moduleType) {

```
    return signFile(`/**
```
```
${license}
```
```
 *
```
```
 * @noflow
```
```
 * @nolint
```
```
 * @preventMunge
```
```
 * ${getSigningToken()}
```
```
 */
```
```
${source}`);
```
```
  },
```

  /****************** RN_FB_PROFILING ******************/

  [RN_FB_PROFILING](source, globalName, filename, moduleType) {

```
    return signFile(`/**
```
```
${license}
```
```
 *
```
```
 * @noflow
```
```
 * @nolint
```
```
 * @preventMunge
```
```
 * ${getSigningToken()}
```
```
 */
```
```
${source}`);
```
```
  },
```
```
};
```
```
const reconcilerWrappers = {
```

  /***************** NODE_DEV (reconciler only) *****************/

  [NODE_DEV](source, globalName, filename, moduleType) {

```
    return `/**
```
```
 * @license React
```
```
 * ${filename}
```
```
 *
```
```
${license}
```
```
 */
```
```
'use strict';
```

if (process.env.NODE_ENV !== "production") {

  module.exports = function $$$reconciler($$$config) {

```
    var exports = {};
```
```
${source}
```
```
    return exports;
```
```
  };
```

  module.exports.default = module.exports;

  Object.defineProperty(module.exports, "__esModule", { value: true });

```
}
```
```
`;
```
```
  },
```

  /***************** NODE_PROD (reconciler only) *****************/

  [NODE_PROD](source, globalName, filename, moduleType) {

```
    return `/**
```
```
 * @license React
```
```
 * ${filename}
```
```
 *
```
```
${license}
```
```
 */
```

module.exports = function $$$reconciler($$$config) {

```
    var exports = {};
```
```
${source}
```
```
    return exports;
```
```
};
```

module.exports.default = module.exports;

Object.defineProperty(module.exports, "__esModule", { value: true });

```
`;
```
```
  },
```

  /***************** NODE_PROFILING (reconciler only) *****************/

  [NODE_PROFILING](source, globalName, filename, moduleType) {

```
    return `/**
```
```
 * @license React
```
```
 * ${filename}
```
```
 *
```
```
${license}
```
```
 */
```

module.exports = function $$$reconciler($$$config) {

```
    var exports = {};
```
```
${source}
```
```
    return exports;
```
```
};
```

module.exports.default = module.exports;

Object.defineProperty(module.exports, "__esModule", { value: true });

```
`;
```
```
  },
```
```
};
```
```
function wrapBundle(
```
```
  source,
```
```
  bundleType,
```
```
  globalName,
```
```
  filename,
```
```
  moduleType,
```
```
  wrapWithModuleBoundaries
```
```
) {
```
```
  if (wrapWithModuleBoundaries) {
```
```
    switch (bundleType) {
```
```
      case NODE_DEV:
```
```
      case NODE_PROFILING:
```
```
      case FB_WWW_DEV:
```
```
      case FB_WWW_PROFILING:
```
```
      case RN_OSS_DEV:
```
```
      case RN_OSS_PROFILING:
```
```
      case RN_FB_DEV:
```
```
      case RN_FB_PROFILING:
```

        // Remove the 'use strict' directive from source.

        // The module start wrapper will add its own.

        // This directive is only meaningful when it is the first statement in a file or function.

        source = source.replace(USE_STRICT_HEADER_REGEX, '');

        // Certain DEV and Profiling bundles should self-register their own module boundaries with DevTools.

        // This allows the Timeline to de-emphasize (dim) internal stack frames.

```
        source = `
```

          ${registerInternalModuleStart(globalName)}

```
          ${source}
```

          ${registerInternalModuleStop(globalName)}

```
        `;
```
```
        break;
```
```
    }
```
```
  }
```
```
  if (bundleType === BROWSER_SCRIPT) {
```

    // Bundles of type BROWSER_SCRIPT get sent straight to the browser without

    // additional processing. So we should exclude any extra wrapper comments.

```
    return source;
```
```
  }
```
```
  if (moduleType === RECONCILER) {
```

    // Standalone reconciler is only used by third-party renderers.

```
    // It is handled separately.
```

    const wrapper = reconcilerWrappers[bundleType];

    if (typeof wrapper !== 'function') {

```
      throw new Error(
```

        `Unsupported build type for the reconciler package: ${bundleType}.`

```
      );
```
```
    }
```

    return wrapper(source, globalName, filename, moduleType);

```
  }
```
```
  // All the other packages.
```

  const wrapper = wrappers[bundleType];

```
  if (typeof wrapper !== 'function') {
```

    throw new Error(`Unsupported build type: ${bundleType}.`);

```
  }
```

  return wrapper(source, globalName, filename, moduleType);

```
}
```
```
module.exports = {
```
```
  wrapBundle,
```
```
};
```