Custom route in Strapi - To get a blog post by slug

custom-post.ts

// src/api/post/routes/custom-post.ts

module.exports = {
  routes: [
    {
      method: 'GET',
      path: '/posts/slug/:slug',
      handler: 'post.findOneBySlug',
      config: {
        policies: [],
        middlewares: [],
        auth: false,
      },
    },
  ],
};

post.ts

// src/api/post/controllers/custom-post.ts

/**
 * post controller
 */

import { factories } from '@strapi/strapi'

export default factories.createCoreController('api::post.post', ({ strapi }) => ({
  async findOneBySlug(ctx) {
    const { slug } = ctx.params;
    const { query } = ctx;

    try {
      const post = await strapi.db.query('api::post.post').findOne({
        where: { slug },
        populate: ['image', 'categories'],
        ...query,
      });

      if (!post) {
        return ctx.notFound(`Post with slug "${slug}" not found`);
      }

      const sanitizedEntity = await this.sanitizeOutput(post, ctx);
      return this.transformResponse(sanitizedEntity);
    } catch (err) {
      ctx.throw(500, err);
    }
  },
}));