index.ts

import { TsGeneratorPlugin, TFileDesc } from "../../../../src/publicApi";
import { join } from "path";

const generateType = (name: string, type: string): string => `export const ${name}: ${type}`;

export class JsonPlugin extends TsGeneratorPlugin {
  name = "JsonPlugin";

  transformFile({ path, contents }: TFileDesc): TFileDesc {
    const outputFileName = `${path}.d.ts`;

    const json = JSON.parse(contents);

    // assume that json is 1 level nested structure
    const nameTypePairs = Object.keys(json).map((k) => {
      const value = json[k];
      const valueType = typeof value;

      return [k, valueType] as [string, string];
    });

    const types = nameTypePairs.map(([name, type]) => generateType(name, type)).join("\n");

    return {
      contents: types,
      path: outputFileName,
    };
  }

  beforeRun(): TFileDesc {
    return {
      path: join(this.ctx.cwd, "before.ts"),
      contents: `export default "before"`,
    };
  }

  afterRun(): TFileDesc {
    return {
      path: join(this.ctx.cwd, "after.ts"),
      contents: `export default "after"`,
    };
  }
}