replace deprecated request critical issue

lib/webid/lib/get.js

@@ -1,27 +1,35 @@
 module.exports = get
 
-const request = require('request')
+const fetch = require('node-fetch')
 const url = require('url')
 
 function get (webid, callback) {
-  const uri = url.URL(webid)
-  const options = {
-    url: uri,
-    method: 'GET',
-    headers: {
-      Accept: 'text/turtle, application/ld+json'
-    }
+  let uri
+  try {
+    uri = new url.URL(webid)
+  } catch (err) {
+    return callback(new Error('Invalid WebID URI: ' + webid + ': ' + err.message))
   }
 
-  request(options, function (err, res, body) {
-    if (err) {
-      return callback(new Error('Failed to fetch profile from ' + uri.href + ': ' + err))
-    }
-
-    if (res.statusCode !== 200) {
-      return callback(new Error('Failed to retrieve WebID from ' + uri.href + ': HTTP ' + res.statusCode))
-    }
+  const headers = {
+    Accept: 'text/turtle, application/ld+json'
+  }
 
-    callback(null, body, res.headers['content-type'])
-  })
+  fetch(uri.href, { method: 'GET', headers })
+    .then(async res => {
+      if (!res.ok) {
+        return callback(new Error('Failed to retrieve WebID from ' + uri.href + ': HTTP ' + res.status))
+      }
+      const contentType = res.headers.get('content-type')
+      let body
+      if (contentType && contentType.includes('json')) {
+        body = JSON.stringify(await res.json(), null, 2)
+      } else {
+        body = await res.text()
+      }
+      callback(null, body, contentType)
+    })
+    .catch(err => {
+      return callback(new Error('Failed to fetch profile from ' + uri.href + ': ' + err))
+    })
 }