type: getBytecodeFileType()

in packages/metro-transform-worker/src/index.js [498:604]

• 44 lines of code
• 8 McCabe index (conditional complexity)

      type: getBytecodeFileType(file.type),
    });
  }

  return {
    dependencies,
    output,
  };
}

/**
 * Transforms an asset file
 */
async function transformAsset(
  file: AssetFile,
  context: TransformationContext,
): Promise<TransformResponse> {
  const assetTransformer = require('./utils/assetTransformer');
  const {assetRegistryPath, assetPlugins} = context.config;

  const result = await assetTransformer.transform(
    getBabelTransformArgs(file, context),
    assetRegistryPath,
    assetPlugins,
  );

  const jsFile = {
    ...file,
    type: 'js/module/asset',
    ast: result.ast,
    functionMap: null,
  };

  return transformJS(jsFile, context);
}

/**
 * Transforms a JavaScript file with Babel before processing the file with
 * the generic JavaScript transformation.
 */
async function transformJSWithBabel(
  file: JSFile,
  context: TransformationContext,
): Promise<TransformResponse> {
  const {babelTransformerPath} = context.config;
  // $FlowFixMe[unsupported-syntax] dynamic require
  const transformer: BabelTransformer = require(babelTransformerPath);

  const transformResult = await transformer.transform(
    getBabelTransformArgs(file, context),
  );

  const jsFile: JSFile = {
    ...file,
    ast: transformResult.ast,
    functionMap: transformResult.functionMap ?? null,
  };

  return await transformJS(jsFile, context);
}

async function transformJSON(
  file: JSONFile,
  {options, config, projectRoot}: TransformationContext,
): Promise<TransformResponse> {
  let code =
    config.unstable_disableModuleWrapping === true
      ? JsFileWrapping.jsonToCommonJS(file.code)
      : JsFileWrapping.wrapJson(file.code, config.globalPrefix);
  let map = [];

  // TODO: When we can reuse transformJS for JSON, we should not derive `minify` separately.
  const minify =
    options.minify &&
    options.unstable_transformProfile !== 'hermes-canary' &&
    options.unstable_transformProfile !== 'hermes-stable';

  if (minify) {
    ({map, code} = await minifyCode(
      config,
      projectRoot,
      file.filename,
      code,
      file.code,
      map,
    ));
  }

  let jsType: JSFileType;

  if (file.type === 'asset') {
    jsType = 'js/module/asset';
  } else if (file.type === 'script') {
    jsType = 'js/script';
  } else {
    jsType = 'js/module';
  }

  const output = [
    {
      data: {code, lineCount: countLines(code), map, functionMap: null},
      type: jsType,
    },
  ];

  if (options.runtimeBytecodeVersion != null) {
    output.push({