1type ReplaceActionResult = string | false | undefined;
2
3interface ReplaceContentOptions {
4callback(content: string): Promise<ReplaceActionResult> | ReplaceActionResult;
5directory?: string;
6globOptions?: fg.Options;
7name?: string;
8pattern: fg.Pattern | fg.Pattern[];
9silent?: boolean;
10}

1async function fixCjsDts() {
2const results = await replaceContent({
3    directory: 'dist',
4    name: 'fix-cjs-dts',
5    pattern: '**/*.d.ts',
6    callback: content => {
7      const { exp, named } =
8        /(?<exp>export (?<named>.+) from 'some-packages';)/u.exec(content)?.groups ?? {};
9      const { exportDefault } =
10        /(?<exportDefault>export \{ somePackage as default \};)/u.exec(content)?.groups ?? {};
11      
12      if (exp && named) {
13      	const statement = `declare namespace SomePackage {
14export ${named.replace('default as somePackage', 'somePackage')};
15
16${exportDefault}
17}
18
19export = SomePackage;`;
20
21        return (
22          content
23            .replace(`\n${exp}`, '')
24            .replace(`\n${exportDefault}`, '') + statement
25        );
26      }
27      
28      return false;
29    }
30});
31
32// results is an array with the replace files content.
33console.log(result);
34}