Extract a TypeScript type from a Swagger Spec website

swagger-to-ts.js

/* Used to extract a from a Swagger API spec */
function generateTypeScriptInterface(targetDef, definitions) {
  if (typeof targetDef === 'string') {
    definitions =
      definitions ||
      window.__defs__ ||
      (window.__defs__ = JSON.parse(document.querySelector('body pre').textContent).definitions);

    targetDef = definitions[targetDef];
  }

  if (!targetDef) throw Error('No valid type found!');

  const body = JSON.stringify(
    Object.fromEntries(
      Object.entries(targetDef.properties).map(([propName, typeDef]) => [
        propName,
        typeDef.type === 'integer'
          ? 'number'
          : typeDef.type
          ? typeDef.type === 'array'
            ? `${typeDef.items.type || typeDef.items.$ref}[]`
            : typeDef.type === 'string'
            ? typeDef.enum
              ? typeDef.enum.map(i => `'${i}'`).join('|')
              : 'string'
            : typeDef.type
          : typeDef.$ref,
      ]),
    ),
  )
    .replace(/#\/definitions\//g, '')
    .replace(/"?(')"?/g, '$1')
    .replace(/"(string|number|boolean)"/g, '$1');

  return `export interface ${targetDef.title} ${body}`;
}