📄 Added templates example project

README.md

@@ -10,12 +10,13 @@
 [![Dependencies](https://img.shields.io/badge/dependencies-0-success)](https://www.npmjs.com/package/@moducate/houston?activeTab=dependencies)
 [![Tree-shakeable](https://img.shields.io/badge/esm-tree--shakeable-success)](#)
 
-- 📃 **Fully compliant.** Fully compliant with the [RFC 7807 specification](https://datatracker.ietf.org/doc/html/rfc7807)!
+- 📋 **Fully compliant.** Fully compliant with the [RFC 7807 specification](https://datatracker.ietf.org/doc/html/rfc7807)!
+- ⚙ **Configurable.** Supports [custom JSON stringify functions](#optionsstringify)!
+- 📃 **Support for templating.** Create [template functions](#templates) to generate errors from parameters!
 - 🐁 **Tiny.** Total bundle size comes in at [< 300B minified + gzipped](https://bundlephobia.com/package/moducate/houston)!
 - 💡 **Lightweight.** Tiny (see above), zero dependencies, and tree-shakeable!
 - 💪 **TypeScript.** Fully typed and self-documenting!
 - 🎉 **Support for Node.js >=10.24!**
-- ⚙ **Configurable.** Supports [custom JSON stringify functions](#optionsstringify)!
 
 ## 🚀 Quick Start
 
@@ -47,7 +48,7 @@ You can create error templates using the exported `withTemplate` function:
 const { withTemplate } = require("@moducate/houston");
 const app = require("express")();
 
-const [withUserNotFound, rawUserNotFound] = withTemplate<{ userId: number }>(({ userId }) => ({
+const [withUserNotFound, rawUserNotFound] = withTemplate(({ userId }) => ({
   type: "https://example.com/user-not-found",
   status: 404,
   instance: `/users/${userId}`,
@@ -76,6 +77,19 @@ const [, withNotFound] = withTemplate(() => ({ type: "https://example.com/not-fo
 // => Returns the raw function for transforming an object
 ```
 
+### 💪 TypeScript
+
+`withTemplate` supports TypeScript generics so you can have type definitions for your template's parameters:
+
+```ts
+const [withUserNotFound] = withTemplate<{ userId: number }>(({ userId }) => ({
+  type: "https://example.com/user-not-found",
+  status: 404,
+  instance: `/users/${userId}`,
+}));
+// => withUserNotFound's second parameter (`params`) now has the type `{ userId: number }`
+```
+
 ## 🏷 MIME Type
 
 The exported `mime` constant can be used to obtain the media/MIME type for RFC 7807 JSON errors.
@@ -156,6 +170,10 @@ app.get("/not-found", (_, reply) => {
 
 See the `examples/fast-json-stringify` directory for an example project using Houston with Fastify and fast-json-stringify.
 
+### Templates
+
+See the `examples/templates` directory for an example project using Houston's templating functionality with Express.
+
 ## ⚖ License
 
 Houston is licensed under the [`MIT License`](LICENSE).

examples/templates/package.json

@@ -0,0 +1,8 @@
+{
+  "name": "templates",
+  "private": true,
+  "dependencies": {
+    "express": "^4.17.1",
+    "@moducate/houston": "../.."
+  }
+}

examples/templates/server.js

@@ -0,0 +1,39 @@
+const { withTemplate } = require('@moducate/houston')
+const app = require('express')()
+
+const books = [
+  {
+    id: '1',
+    name: 'The Da Vinci Code',
+    author: 'Dan Brown',
+    publisher: 'Transworld'
+  },
+  {
+    id: '2',
+    name: 'Harry Potter and the Deathly Hallows',
+    author: 'J.K. Rowling',
+    publisher: 'Bloomsbury'
+  }
+]
+
+const [withBookNotFound] = withTemplate(({ bookId }) => ({
+  type: 'https://express.example.com/not-found',
+  status: 404,
+  instance: `/books/${bookId}`,
+  title: 'Book not found.',
+  detail: `No book was found with the ID '${bookId}'.`,
+}))
+
+app.get('/books', (_, res) => {
+  return res.json(books)
+})
+
+app.get('/books/:id', ({ params }, res) => {
+  const book = books.find(x => x.id === params.id)
+  if (book) {
+    return res.json(book)
+  }
+  return withBookNotFound(res, { bookId: params.id })
+})
+
+app.listen(3000)