Extract content type from headers when fetching remote graphs

Author: rubensworks

lib/ldp.js

@@ -9,15 +9,14 @@ const error = require('./http-error')
 const stringToStream = require('./utils').stringToStream
 const serialize = require('./utils').serialize
 const overQuota = require('./utils').overQuota
+const getContentType = require('./utils').getContentType
 const extend = require('extend')
 const rimraf = require('rimraf')
 const ldpContainer = require('./ldp-container')
 const parse = require('./utils').parse
 const fetch = require('node-fetch')
 const { promisify } = require('util')
 
-const DEFAULT_REMOTE_CONTENT_TYPE = 'text/turtle'
-
 const RDF_MIME_TYPES = [
   'text/turtle',            // .ttl
   'text/n3',                // .n3
@@ -286,9 +285,7 @@ class LDP {
     }
     const body = await response.text()
 
-    const contentType = options.contentType || DEFAULT_REMOTE_CONTENT_TYPE
-
-    return promisify(parse)(body, uri, contentType)
+    return promisify(parse)(body, uri, getContentType(response.headers))
   }
 
   /**

lib/utils.js

@@ -226,11 +226,11 @@ function _asyncReadfile (filename) {
 
 /**
  * Get the content type from a headers object
- * @param headers An Express headers object
+ * @param headers An Express or Fetch API headers object
  * @return {string} A content type string
  */
 function getContentType (headers) {
-  const headerValue = headers['content-type']
+  const headerValue = headers.get ? headers.get('content-type') : headers['content-type']
 
   // Default content type as stated by RFC 822
   if (!headerValue) {

test/unit/utils-test.js

@@ -72,16 +72,35 @@ describe('Utility functions', function () {
   })
 
   describe('getContentType()', () => {
-    it('should default to text/plain', () => {
-      assert.equal(utils.getContentType({}), 'text/plain')
-    })
+    describe('for Express headers', () => {
+      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 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')
+      })
     })
 
-    it('should get a content type without its charset', () => {
-      assert.equal(utils.getContentType({ 'content-type': 'text/html; charset=us-ascii' }), 'text/html')
+    describe('for Fetch API headers', () => {
+      it('should default to text/plain', () => {
+        // eslint-disable-next-line no-undef
+        assert.equal(utils.getContentType(new Headers({})), 'text/plain')
+      })
+
+      it('should get a basic content type', () => {
+        // eslint-disable-next-line no-undef
+        assert.equal(utils.getContentType(new Headers({'content-type': 'text/html'})), 'text/html')
+      })
+
+      it('should get a content type without its charset', () => {
+        // eslint-disable-next-line no-undef
+        assert.equal(utils.getContentType(new Headers({'content-type': 'text/html; charset=us-ascii'})), 'text/html')
+      })
     })
   })
 })