From b282b5363aab1ca578c1fccd5fe72f69f0f42714 Mon Sep 17 00:00:00 2001
From: bergi <bergi@axolotlfarm.org>
Date: Thu, 15 Jul 2021 21:49:01 +0200
Subject: [PATCH] feat: added Headers class to fetch, added .config method to
 fetch

---
 FetchFactory.js           | 38 ++++++++++++++++++----
 package.json              |  1 +
 test/FetchFactory.test.js | 68 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 101 insertions(+), 6 deletions(-)

diff --git a/FetchFactory.js b/FetchFactory.js
index 430f158..bd75ae7 100644
--- a/FetchFactory.js
+++ b/FetchFactory.js
@@ -1,14 +1,40 @@
 import fetch from '@rdfjs/fetch-lite'
 
-class FetchFactory {
-  fetch (url, options = {}) {
-    const factory = typeof this.dataset === 'function' ? this : null
-    const formats = this.formats
+function createFetch (context) {
+  const result = function (url, options = {}) {
+    const factory = typeof context.dataset === 'function' ? context : null
+
+    return fetch(url, {
+      ...options,
+      factory,
+      fetch: context._fetch.fetch,
+      formats: context.formats
+    })
+  }
 
-    return fetch(url, { ...options, factory, formats })
+  result.config = function (key, value) {
+    context._fetch[key] = value
   }
+
+  result.Headers = fetch.Headers
+
+  return result
 }
 
-FetchFactory.exports = ['fetch']
+class FetchFactory {
+  init () {
+    this._fetch = {
+      fetch: null
+    }
+
+    this.fetch = createFetch(this)
+  }
+
+  clone (original) {
+    for (const [key, value] of Object.entries(original._fetch)) {
+      this._fetch[key] = value
+    }
+  }
+}
 
 export default FetchFactory
diff --git a/package.json b/package.json
index 512734c..b1e65e5 100644
--- a/package.json
+++ b/package.json
@@ -39,6 +39,7 @@
     "codecov": "^3.8.2",
     "express-as-promise": "^1.2.0",
     "mocha": "^9.0.2",
+    "nodeify-fetch": "^2.2.1",
     "stricter-standard": "^0.2.0"
   }
 }
diff --git a/test/FetchFactory.test.js b/test/FetchFactory.test.js
index 25f3d46..2bbe11a 100644
--- a/test/FetchFactory.test.js
+++ b/test/FetchFactory.test.js
@@ -1,9 +1,11 @@
 import { strictEqual } from 'assert'
 import rdf from '@rdfjs/data-model'
+import fetch from '@rdfjs/fetch-lite'
 import formats from '@rdfjs/formats-common'
 import toNT from '@rdfjs/to-ntriples'
 import withServer from 'express-as-promise/withServer.js'
 import { describe, it } from 'mocha'
+import nodeFetch from 'nodeify-fetch'
 import DataFactory from '../DataFactory.js'
 import DatasetFactory from '../DatasetFactory.js'
 import Environment from '../Environment.js'
@@ -22,6 +24,19 @@ describe('FetchFactory', () => {
     strictEqual(typeof FetchFactory, 'function')
   })
 
+  describe('.clone', () => {
+    it('should copy the key-value pairs of the config', () => {
+      const env = new Environment([FetchFactory])
+      env._fetch.a = '1'
+      env._fetch.b = {}
+
+      const clone = env.clone()
+
+      strictEqual(clone._fetch.a, env._fetch.a)
+      strictEqual(clone._fetch.b, env._fetch.b)
+    })
+  })
+
   describe('.fetch', () => {
     it('should be a method', () => {
       const env = new Environment([FetchFactory])
@@ -97,5 +112,58 @@ describe('FetchFactory', () => {
         strictEqual(called, true)
       })
     })
+
+    it('should use an alternative fetch implementation if set in the config', async () => {
+      await withServer(async server => {
+        let called = false
+        const customFetch = (url, options) => {
+          called = true
+
+          return nodeFetch(url, options)
+        }
+        const env = new Environment([DataFactory, FetchFactory, FormatsFactory])
+        env.fetch.config('fetch', customFetch)
+        env.formats.import(formats)
+
+        server.app.get('/', (req, res) => {
+          res.set('content-type', 'text/turtle').end(toNT(example.quad))
+        })
+
+        await env.fetch(await server.listen())
+
+        strictEqual(called, true)
+      })
+    })
+  })
+
+  describe('.fetch.config', () => {
+    it('should be a function', () => {
+      const env = new Environment([FetchFactory])
+
+      strictEqual(typeof env.fetch.config, 'function')
+    })
+
+    it('should change the given config value', () => {
+      const value = {}
+      const env = new Environment([FetchFactory])
+
+      env.fetch.config('fetch', value)
+
+      strictEqual(env._fetch.fetch, value)
+    })
+  })
+
+  describe('.fetch.Headers', () => {
+    it('should be a constructor', () => {
+      const env = new Environment([FetchFactory])
+
+      strictEqual(typeof env.fetch.Headers, 'function')
+    })
+
+    it('should be the Headers class from @rdfjs/fetch-lite', () => {
+      const env = new Environment([FetchFactory])
+
+      strictEqual(env.fetch.Headers, fetch.Headers)
+    })
   })
 })