export async function extractDependenciesAndSize()

in repo-scripts/size-analysis/analysis-helper.ts [71:171]
94 lines of code
3 McCabe index (conditional complexity)

export async function extractDependenciesAndSize(
  exportName: string,
  jsBundle: string
): Promise<ExportData> {
  const input = tmp.fileSync().name + '.js';
  const externalDepsResolvedOutput = tmp.fileSync().name + '.js';
  const externalDepsNotResolvedOutput = tmp.fileSync().name + '.js';

  const exportStatement = `export { ${exportName} } from '${path.resolve(
    jsBundle
  )}';`;
  fs.writeFileSync(input, exportStatement);

  // Run Rollup on the JavaScript above to produce a tree-shaken build
  const externalDepsResolvedBundle = await rollup.rollup({
    input,
    plugins: [
      resolve({
        mainFields: ['esm2017', 'module', 'main']
      }),
      commonjs()
    ]
  });
  await externalDepsResolvedBundle.write({
    file: externalDepsResolvedOutput,
    format: 'es'
  });
  const externalDepsNotResolvedBundle = await rollup.rollup({
    input,
    // exclude all firebase dependencies and tslib
    external: id => id.startsWith('@firebase') || id === 'tslib'
  });
  await externalDepsNotResolvedBundle.write({
    file: externalDepsNotResolvedOutput,
    format: 'es'
  });
  const dependencies: MemberList = extractAllTopLevelSymbols(
    externalDepsNotResolvedOutput
  );

  const externalDepsResolvedOutputContent = fs.readFileSync(
    externalDepsResolvedOutput,
    'utf-8'
  );
  // Extract size of minified build
  const externalDepsNotResolvedOutputContent = fs.readFileSync(
    externalDepsNotResolvedOutput,
    'utf-8'
  );
  const externalDepsResolvedOutputContentMinimized = await terser.minify(
    externalDepsResolvedOutputContent,
    {
      format: {
        comments: false
      },
      mangle: { toplevel: true },
      compress: false
    }
  );
  const externalDepsNotResolvedOutputContentMinimized = await terser.minify(
    externalDepsNotResolvedOutputContent,
    {
      format: {
        comments: false
      },
      mangle: { toplevel: true },
      compress: false
    }
  );
  const exportData: ExportData = {
    name: '',
    classes: [],
    functions: [],
    variables: [],
    enums: [],
    unknown: [],
    externals: {},
    size: 0,
    sizeWithExtDeps: 0
  };
  exportData.name = exportName;
  for (const key of Object.keys(dependencies) as Array<keyof MemberList>) {
    exportData[key] = dependencies[key];
  }

  exportData.externals = extractExternalDependencies(
    externalDepsNotResolvedOutput
  );
  exportData.size = Buffer.byteLength(
    externalDepsNotResolvedOutputContentMinimized.code!,
    'utf-8'
  );
  exportData.sizeWithExtDeps = Buffer.byteLength(
    externalDepsResolvedOutputContentMinimized.code!,
    'utf-8'
  );
  fs.unlinkSync(input);
  fs.unlinkSync(externalDepsNotResolvedOutput);
  fs.unlinkSync(externalDepsResolvedOutput);
  return exportData;
}