feat: Add GraphQL fetcher

src/enums.js

@@ -43,6 +43,8 @@ const Fetcher = {
   ACTIVITYPUB: 'activitypub',
   /** DNS module from Node.js */
   DNS: 'dns',
+  /** GraphQL over HTTP requests */
+  GRAPHQL: 'graphql',
   /** Basic HTTP requests */
   HTTP: 'http',
   /** IRC module from Node.js */

src/fetcher/graphql.js

@@ -0,0 +1,80 @@
+/*
+Copyright 2023 Yarmo Mackenbach
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+const axios = require('axios')
+
+/**
+ * @module fetcher/graphql
+ */
+
+/**
+ * The request's timeout value in milliseconds
+ * @constant {number} timeout
+ */
+module.exports.timeout = 5000
+
+/**
+ * Execute a GraphQL query via HTTP request
+ * @function
+ * @async
+ * @param {object} data         - Data used in the request
+ * @param {string} data.url     - The URL pointing at the GraphQL HTTP endpoint
+ * @param {string} data.query   - The GraphQL query to fetch the data containing the proof
+ * @returns {object|string}
+ */
+module.exports.fn = async (data, opts) => {
+  let timeoutHandle
+  const timeoutPromise = new Promise((resolve, reject) => {
+    timeoutHandle = setTimeout(
+      () => reject(new Error('Request was timed out')),
+      data.fetcherTimeout ? data.fetcherTimeout : module.exports.timeout
+    )
+  })
+
+  const fetchPromise = new Promise((resolve, reject) => {
+    if (!data.url) {
+      reject(new Error('No valid URI provided'))
+      return
+    }
+
+    let jsonData
+    try {
+      jsonData = JSON.parse(data.query)
+    } catch (error) {
+      reject(new Error('Invalid GraphQL query object'))
+    }
+
+    axios.post(data.url, jsonData, {
+      headers: {
+        'Content-Type': 'application/json',
+        'User-Agent': `doipjs/${require('../../package.json').version}`
+      },
+      validateStatus: function (status) {
+        return status >= 200 && status < 400
+      }
+    })
+      .then(res => {
+        resolve(res.data)
+      })
+      .catch(e => {
+        reject(e)
+      })
+  })
+
+  return Promise.race([fetchPromise, timeoutPromise]).then((result) => {
+    clearTimeout(timeoutHandle)
+    return result
+  })
+}

src/fetcher/index.js

@@ -16,6 +16,7 @@ limitations under the License.
 
 exports.activitypub = require('./activitypub')
 exports.dns = require('./dns')
+exports.graphql = require('./graphql')
 exports.http = require('./http')
 exports.irc = require('./irc')
 exports.matrix = require('./matrix')