Koa route helper & example (#5)

examples/express/routes/users/[id]/likes/index.js

@@ -1,3 +1,3 @@
 module.exports.get = (req, res) => {
-  res.send({ userId: req.params.id, likes: ['a', 'b', 'c' ]})
+  res.send({ userId: req.params.id, likes: ['a', 'b', 'c' ] })
 }

examples/koa/index.js

@@ -0,0 +1,14 @@
+const Koa = require('koa')
+const soda = require('soda')
+const app = new Koa()
+
+async function startup() {
+  const sodaRouter = await soda.withKoaRouter('./routes')
+  app
+    .use(sodaRouter.routes())
+    .use(sodaRouter.allowedMethods())
+
+  app.listen(5555)
+  console.log('Server listening on :5555')
+}
+startup()

examples/koa/package.json

@@ -0,0 +1,17 @@
+{
+  "name": "soda-example-koa",
+  "version": "0.0.0",
+  "description": "",
+  "main": "index.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "author": "",
+  "license": "MIT",
+  "repository": "tmarshall/soda",
+  "dependencies": {
+    "@koa/router": "^12.0.0",
+    "koa": "^2.13.4",
+    "soda": "latest"
+  }
+}

examples/koa/routes/index.js

@@ -0,0 +1,6 @@
+module.exports.get = (ctx, next) => {
+  ctx.body = {
+    success: true,
+    page: 'root',
+  }
+}

examples/koa/routes/users/[id]/index.js

@@ -0,0 +1,5 @@
+module.exports.get = (ctx, next) => {
+  ctx.body = {
+    userId: parseInt(ctx.params.id, 10),
+  }
+}

examples/koa/routes/users/[id]/likes/[likeId].js

@@ -0,0 +1,3 @@
+module.exports.get = (ctx, next) => {
+  ctx.body = { userId: ctx.params.id, likeId: ctx.params.likeId }
+}

examples/koa/routes/users/[id]/likes/index.js

@@ -0,0 +1,3 @@
+module.exports.get = (ctx, next) => {
+  ctx.body = { userId: ctx.params.id, likes: ['a', 'b', 'c' ] }
+}

examples/koa/routes/users/index.js

@@ -0,0 +1,14 @@
+const mockQuery = () => new Promise((resolve) => resolve([{
+  id: 1,
+  name: 'Tim',
+}, {
+  id: 2,
+  name: 'Cosmo'
+}]))
+
+module.exports.get = async (ctx, next) => {
+  const users = await mockQuery()
+  ctx.body = {
+    users,
+  }
+}

readme.md

@@ -212,3 +212,31 @@ startup()
 ### Routes in Express
 
 Any route filepath like `routes/accounts/[accountId].js` will get converted to an Express route path like `/routes/accounts/:accountId`.
+
+## Koa middleware
+
+Want to use [Koa](https://koajs.com/)? No problem.
+
+```js
+const Koa = require('koa')
+const soda = require('soda')
+const app = new Koa()
+
+async function startup() {
+  // `withKoaRouter` takes the same arguments as `soda.serve`
+  const sodaRouter = await soda.withKoaRouter('./routes')
+  app
+    .use(sodaRouter.routes())
+    .use(sodaRouter.allowedMethods())
+
+  app.listen(5555)
+  console.log('Server listening on :5555')
+}
+startup()
+```
+
+### Routes in Koa
+
+`withKoaRouter` uses [the `@koa/router` package](https://www.npmjs.com/package/koa-router). The return value is an instance of the Koa router.
+
+Any route filepath like `routes/accounts/[accountId].js` will get converted to a Koa route path like `/routes/accounts/:accountId`.

src/index.ts

@@ -6,6 +6,7 @@ import serve from './serve'
 import walkRoutes from './walkRoutes'
 import walkMiddleware from './walkMiddleware'
 import withExpress from './withExpress'
+import withKoaRouter from './withKoaRouter'
 
 export interface SodaRequest extends IncomingMessage {
   params: Record<string, string | number>
@@ -34,4 +35,5 @@ module.exports = {
   serve,
   walkRoutes,
   withExpress,
+  withKoaRouter,
 }

src/withExpress.ts

@@ -1,6 +1,6 @@
 import type { DefineRoute, RouteVerbKey } from './walkRoutes'
 
-import walkRoutes, { ParamTypes } from './walkRoutes'
+import walkRoutes from './walkRoutes'
 import walkMiddleware from './walkMiddleware'
 
 interface RouteDefinition {
@@ -9,15 +9,6 @@ interface RouteDefinition {
   func: Function
 }
 
-const typedParamAttributes = {
-  [ParamTypes.string]: {
-    mutator: (paramString: string) => paramString,
-  },
-  [ParamTypes.number]: {
-    mutator: (paramString: string) => Number(paramString)
-  },
-}
-
 const defineRoute: DefineRoute<RouteDefinition> = ({ verb, routePath, func }) => {
   const pathParamCheck = new RegExp(`/\\[(?<paramName>[a-zA-Z_$][a-zA-Z0-9_$]*)\\](?=/|$)`, 'g')
 

src/withKoaRouter.ts

@@ -0,0 +1,56 @@
+import type { DefineRoute, RouteVerbKey } from './walkRoutes'
+
+import walkRoutes from './walkRoutes'
+import walkMiddleware from './walkMiddleware'
+
+interface RouteDefinition {
+  verb: RouteVerbKey
+  path: string
+  func: Function
+}
+
+const defineRoute: DefineRoute<RouteDefinition> = ({ verb, routePath, func }) => {
+  const pathParamCheck = new RegExp(`/\\[(?<paramName>[a-zA-Z_$][a-zA-Z0-9_$]*)\\](?=/|$)`, 'g')
+
+  if (!pathParamCheck.test(routePath)) {
+    return {
+      verb,
+      path: routePath,
+      func,
+    }
+  }
+
+  const parts = routePath.split(pathParamCheck)
+  let resultExpressPath = ''
+
+  for (let i = 0; i < parts.length; i++) {
+    if (i % 2 === 0) {
+      resultExpressPath += parts[i]
+      continue
+    }
+
+    const paramName = parts[i]
+    resultExpressPath += `/:${paramName}`
+  }
+
+  return {
+    verb,
+    path: resultExpressPath,
+    func,
+  }
+}
+
+export default async function withKoaRouter(routesDirpath?: string, middlewareDirpath?: string) {
+  const Router = require('@koa/router')
+
+  const middleware = await walkMiddleware(middlewareDirpath)
+  const routes = await walkRoutes<RouteDefinition>(routesDirpath, middleware, defineRoute)
+
+  const koaRouter = new Router()
+
+  for (let routeDef of routes) {
+    koaRouter[routeDef.verb](routeDef.path, routeDef.func)
+  }
+
+  return koaRouter
+}