Micro router for js

micro-router-parser.js

class Router {
  routes = {}
  
  baseUrl = ""
  
  constructor(baseUrl) {
    this.baseUrl = baseUrl
  }
  
  register = (method) => {
    return (pattern, handler) => {
      const path = `${this.baseUrl}${pattern}`
      const placeholders = []
      const body = path.replace(/:(\w+)/g, (_,x) => {
        placeholders.push(x);
        return `(\\w+)`;
      });
      const route = {
        path,
        handler,
        placeholders,
        pattern: new RegExp(`^${body}$`, "i")
      }
      
      if (method in this.routes) {
        this.routes[method].push(route)
      } else {
        this.routes[method] = [route]
      }
      
      return this
    }
  }
  
  match(method, url) {
    if (method in this.routes) {
      const candidates = this.routes[method];
      const match = candidates.find(route => route.pattern.test(url))
      
      if (match) {
        const parsed = match.pattern.exec(url)
        
        const args = parsed.length > 1 
          ? parsed
            .slice(1)
            .reduce(
              (acc, x, i) => ({ ...acc, [match.placeholders[i]]: x }), 
              {}
            )
          : undefined
        
        return match.handler(args)
      }
    }
    
    return null
  }
  
  get = this.register("GET")
  post = this.register("POST")
  put = this.register("PUT")
  patch = this.register("PATCH")
  delete = this.register("DELETE")
}

const baseUrl = "https://foo.com/api"

const router = new Router(baseUrl)

const matcher = router
  .get("/foos", () => ({
    delay: 500,
    status: 200,
    data: [{ id: "id-1", bar: "2" }]
  }))
  .get("/foos/:id", ({ id }) => ({
    delay: 500,
    status: 200,
    data: {
      id: id,
      bar: "asdas"
    }
  }))
  .post("/bars", () => ({
    delay: 100,
    status: 200,
    data: {
      id: "id-1234"
    }
  }))

const match = matcher.match("GET", "https://foo.com/api/foos/ab")

console.log(match)