Implement fetchDocument without async.

Author: RubenVerborgh

lib/handlers/allow.js

@@ -3,7 +3,6 @@ module.exports = allow
 var ACL = require('../acl-checker')
 var $rdf = require('rdflib')
 var url = require('url')
-var async = require('async')
 var utils = require('../utils')
 
 function allow (mode) {
@@ -59,31 +58,30 @@ function allow (mode) {
  */
 function fetchDocument (host, ldp, baseUri) {
   return function fetch (uri, callback) {
-    var graph = $rdf.graph()
-    async.waterfall([
-      function readFile (cb) {
-        // If local request, slice off the initial baseUri
-        // S(uri).chompLeft(baseUri).s
-        var newPath = uri.startsWith(baseUri)
-          ? uri.slice(baseUri.length)
-          : uri
-        // Determine the root file system folder to look in
-        // TODO prettify this
-        var root = !ldp.idp ? ldp.root : ldp.root + host + '/'
-        // Derive the file path for the resource
-        var documentPath = utils.uriToFilename(newPath, root)
-        var documentUri = url.parse(documentPath)
-        documentPath = documentUri.pathname
-        return ldp.readFile(documentPath, cb)
-      },
-      function parseFile (body, cb) {
-        try {
-          $rdf.parse(body, graph, uri, 'text/turtle')
-        } catch (err) {
-          return cb(err, graph)
-        }
-        return cb(null, graph)
-      }
-    ], callback)
+    readFile(uri, host, ldp, baseUri).then(body => {
+      const graph = $rdf.graph()
+      $rdf.parse(body, graph, uri, 'text/turtle')
+      return graph
+    })
+    .then(graph => callback(null, graph), callback)
   }
 }
+
+// Reads the given file, returning its contents
+function readFile (uri, host, ldp, baseUri) {
+  return new Promise((resolve, reject) => {
+    // If local request, slice off the initial baseUri
+    // S(uri).chompLeft(baseUri).s
+    var newPath = uri.startsWith(baseUri)
+      ? uri.slice(baseUri.length)
+      : uri
+    // Determine the root file system folder to look in
+    // TODO prettify this
+    var root = !ldp.idp ? ldp.root : ldp.root + host + '/'
+    // Derive the file path for the resource
+    var documentPath = utils.uriToFilename(newPath, root)
+    var documentUri = url.parse(documentPath)
+    documentPath = documentUri.pathname
+    ldp.readFile(documentPath, (e, c) => e ? reject(e) : resolve(c))
+  })
+}