Add helper function to safely extract content type from headers

Author: rubensworks

lib/handlers/put.js

@@ -1,14 +1,15 @@
 module.exports = handler
 
 const debug = require('debug')('solid:put')
+const getContentType = require('../utils').getContentType
 
 async function handler (req, res, next) {
   const ldp = req.app.locals.ldp
   debug(req.originalUrl)
   res.header('MS-Author-Via', 'SPARQL')
 
   try {
-    await ldp.put(req, req, req.headers['content-type'])
+    await ldp.put(req, req, getContentType(req.headers))
     debug('succeded putting the file')
 
     res.sendStatus(201)

lib/utils.js

@@ -9,6 +9,7 @@ module.exports.fullUrlForReq = fullUrlForReq
 module.exports.routeResolvedFile = routeResolvedFile
 module.exports.getQuota = getQuota
 module.exports.overQuota = overQuota
+module.exports.getContentType = getContentType
 
 const fs = require('fs')
 const path = require('path')
@@ -222,3 +223,20 @@ function actualSize (root) {
 function _asyncReadfile (filename) {
   return util.promisify(fs.readFile)(filename, 'utf-8')
 }
+
+/**
+ * Get the content type from a headers object
+ * @param headers An Express headers object
+ * @return {string} A content type string
+ */
+function getContentType (headers) {
+  const headerValue = headers['content-type']
+
+  // Default content type as stated by RFC 822
+  if (!headerValue) {
+    return 'text/plain'
+  }
+
+  // Remove charset suffix
+  return headerValue.split(';')[0]
+}

test/unit/utils-test.js

@@ -70,4 +70,18 @@ describe('Utility functions', function () {
       assert.equal(utils.fullUrlForReq(req), 'https://example.com/resource1?sort=desc')
     })
   })
+
+  describe('getContentType()', () => {
+    it('should default to text/plain', () => {
+      assert.equal(utils.getContentType({}), 'text/plain')
+    })
+
+    it('should get a basic content type', () => {
+      assert.equal(utils.getContentType({ 'content-type': 'text/html' }), 'text/html')
+    })
+
+    it('should get a content type without its charset', () => {
+      assert.equal(utils.getContentType({ 'content-type': 'text/html; charset=us-ascii' }), 'text/html')
+    })
+  })
 })