feat: initial version

.changeset/silver-lemons-buy.md

@@ -0,0 +1,5 @@
+---
+"express-rdf-problem-details": major
+---
+
+First release

README.md

@@ -0,0 +1,25 @@
+# express-rdf-problem-details
+
+This package wraps [express-http-problem-details](https://github.com/PDMLab/express-http-problem-details) so that RDF/Linked Data express applications will return Problem documents ([RFC7807](https://tools.ietf.org/html/rfc7807)) as valid JSON-LD.
+
+This is done simply by adding a `Link` header pointing to a JSON-LD `@context`. By default, it's the [context provided by Hydra Community Group](http://www.hydra-cg.com/spec/latest/core/#example-31-rfc-7807-compatible-error-description)
+
+## Usage
+
+```typescript
+import express from 'express'
+import * as error from 'express-rdf-problem-details'
+import { NotFoundMapper } from './error-mappers'
+
+const app = express()
+
+// All params optional
+express.use(error.handler({
+  // change the @context URL
+  context: 'http://example.com/error.jsonld',
+  // additional mappers to customize error documents
+  mappers: [new NotFoundMapper()] 
+}))
+```
+
+Implementing mappers is explained in [PDMLab/express-http-problem-details](https://github.com/PDMLab/express-http-problem-details#example)

index.ts

@@ -1 +1,21 @@
-export default 'foo'
+import type * as express from 'express'
+import { HttpProblemResponse } from 'express-http-problem-details'
+import { DefaultMappingStrategy, IErrorMapper, MapperRegistry } from 'http-problem-details-mapper'
+import setLink from 'set-link'
+
+interface Factory {
+  (arg?: { mappers?: IErrorMapper[]; context?: string }): express.ErrorRequestHandler
+}
+
+export const handler: Factory = ({ mappers = [], context = 'https://www.w3.org/ns/hydra/error' } = {}) => {
+  const registry = mappers.reduce((r, mapper) => r.registerMapper(mapper, true), new MapperRegistry())
+
+  const problemDetailsHandler = HttpProblemResponse({ strategy: new DefaultMappingStrategy(registry) })
+
+  return (err, req, res, next) => {
+    setLink.attach(res)
+
+    res.setLink(context, 'http://www.w3.org/ns/json-ld#context')
+    problemDetailsHandler(err, req, res, next)
+  }
+}

package.json

@@ -1,7 +1,7 @@
 {
-  "name": "ts-template",
+  "name": "express-rdf-problem-details",
+  "description": "hydra-box error handler which returns HTTP Problem Details with JSON-LD context link",
   "version": "0.0.0",
-  "private": true,
   "type": "module",
   "main": "main.js",
   "module": "index.js",
@@ -17,6 +17,11 @@
     "*.js",
     "*.d.ts"
   ],
+  "dependencies": {
+    "express-http-problem-details": "^0.2.1",
+    "http-problem-details-mapper": "^0.1.7",
+    "set-link": "^1.0.0"
+  },
   "devDependencies": {
     "@babel/core": "^7.16.0",
     "@babel/preset-env": "^7.16.0",
@@ -25,9 +30,13 @@
     "@changesets/cli": "^2.17.0",
     "@tpluscode/eslint-config": "^0.3.0",
     "@types/chai": "^4.2.22",
+    "@types/express": "^4.17.13",
+    "@types/http-errors": "^1.8.1",
     "@types/mocha": "^9.0.0",
+    "@types/set-link": "^1",
     "@types/sinon": "^10.0.6",
     "@types/sinon-chai": "^3.2.5",
+    "@types/supertest": "^2.0.11",
     "@typescript-eslint/eslint-plugin": "^5.2.0",
     "@typescript-eslint/parser": "^5.2.0",
     "c8": "^7.10.0",
@@ -38,24 +47,27 @@
     "eslint-plugin-import": "^2.25.2",
     "eslint-plugin-node": "^11.1.0",
     "eslint-plugin-promise": "^5.1.1",
+    "express": "^4.17.1",
     "husky": "^7.0.4",
+    "http-errors": "^1.8.0",
     "lint-staged": "^11.2.6",
     "mocha": "^9.1.3",
     "sinon": "^11.1.2",
     "sinon-chai": "^3.7.0",
     "standard": "^16.0.3",
+    "supertest": "^6.1.6",
     "typescript": "^4.3.4"
   },
   "repository": {
     "type": "git",
-    "url": "git+https://github.com/tpluscode/ts-template.git"
+    "url": "git+https://github.com/hypermedia-app/hydra-box-problem-details.git"
   },
   "author": "Tomasz Pluskiewicz",
   "license": "MIT",
   "bugs": {
-    "url": "https://github.com/tpluscode/ts-template/issues"
+    "url": "https://github.com/hypermedia-app/hydra-box-problem-details/issues"
   },
-  "homepage": "https://github.com/tpluscode/ts-template#readme",
+  "homepage": "https://github.com/hypermedia-app/hydra-box-problem-details#readme",
   "mocha": {
     "watch-files": [
       "./**/*.ts"

test/index.test.ts

@@ -1,9 +1,62 @@
 import { describe, it } from 'mocha'
+import express from 'express'
+import request from 'supertest'
+import { BadRequest } from 'http-errors'
 import { expect } from 'chai'
-import index from '..'
+import * as error from '..'
 
-describe('index', () => {
-  it('exports foo', () => {
-    expect(index).to.eq('foo')
+describe('express-rdf-problem-details', () => {
+  it('sets context link', async () => {
+    // given
+    const app = express()
+    app
+      .use((req, res, next) => next(404))
+      .use(error.handler())
+
+    // when
+    const response = request(app).get('/foo')
+
+    await response.expect('link', /^<https:\/\/www\.w3\.org\/ns\/hydra\/error>/)
+  })
+
+  it('allows customizing mappers', async () => {
+    // given
+    const app = express()
+    app
+      .use((req, res, next) => next(new BadRequest()))
+      .use(error.handler({
+        mappers: [new (class {
+          get error() {
+            return 'BadRequestError'
+          }
+
+          mapError() {
+            return {
+              title: 'something wrong',
+              status: 400,
+            }
+          }
+        })()],
+      }))
+
+    // when
+    const { body } = await request(app).get('/foo')
+
+    expect(body).to.have.property('title', 'something wrong')
+  })
+
+  it('allows changing context', async () => {
+    // given
+    const app = express()
+    app
+      .use((req, res, next) => next(404))
+      .use(error.handler({
+        context: 'https://example.com/error.jsonld',
+      }))
+
+    // when
+    const response = request(app).get('/foo')
+
+    await response.expect('link', /^<https:\/\/example\.com\/error\.jsonld>/)
   })
 })