Add file to URL mapping.

Author: RubenVerborgh

lib/handlers/resource-mapper.js

@@ -1,20 +1,21 @@
 const URL = require('url')
-const { extensions } = require('mime-types')
+const { types, extensions } = require('mime-types')
 
 // A ResourceMapper maintains the mapping between HTTP URLs and server filenames,
 // following the principles of the “sweet spot” discussed in
 // https://www.w3.org/DesignIssues/HTTPFilenameMapping.html
 class ResourceMapper {
-  constructor ({ rootPath, multiuser }) {
-    this._rootPath = rootPath.replace(/\/+$/, '')
+  constructor ({ rootUrl, rootPath, multiuser }) {
+    this._rootUrl = removeTrailingSlash(rootUrl)
+    this._rootPath = removeTrailingSlash(rootPath)
     this._multiuser = multiuser
   }
 
   // Maps the request for a given resource and representation format to a server file
   async mapUrlToFile ({ url, contentTypes }) {
     // Split the URL into components
     const { pathname } = typeof url === 'string' ? URL.parse(url) : url
-    const urlExtension = /(\.[^/.]+)?$/.exec(pathname)[0]
+    const urlExtension = getExtension(pathname)
     const urlPath = pathname.substr(0, pathname.length - urlExtension.length)
 
     // Sanity checks
@@ -30,6 +31,27 @@ class ResourceMapper {
 
     return { path }
   }
+
+  // Maps a given server file to a URL
+  async mapFileToUrl ({ path }) {
+    // Determine the URL by shopping off everything after the dollar sign
+    const pathname = path.substring(this._rootPath.length).replace(/\$.*/, '')
+    const url = `${this._rootUrl}${pathname}`
+
+    // Determine the content type
+    const extension = getExtension(path)
+    const contentType = types[extension.substr(1)] || 'application/octet-stream'
+
+    return { url, contentType }
+  }
+}
+
+function removeTrailingSlash (path) {
+  return path ? path.replace(/\/+$/, '') : ''
+}
+
+function getExtension (path) {
+  return /(\.[^/.]+)?$/.exec(path)[0]
 }
 
 module.exports = ResourceMapper

test/unit/resource-mapper-test.js

@@ -4,11 +4,13 @@ const { expect } = chai
 chai.use(require('chai-as-promised'))
 
 const itMapsUrl = asserter(mapsUrl)
+const itMapsFile = asserter(mapsFile)
 
 describe('ResourceMapper', () => {
   describe('A ResourceMapper instance for a single-user setup', () => {
+    const rootUrl = 'http://localhost/'
     const rootPath = '/var/www/folder/'
-    const mapper = new ResourceMapper({ rootPath })
+    const mapper = new ResourceMapper({ rootUrl, rootPath })
 
     // PUT base cases from https://www.w3.org/DesignIssues/HTTPFilenameMapping.html
 
@@ -123,6 +125,50 @@ describe('ResourceMapper', () => {
         url: 'http://localhost/space/../bar'
       },
       new Error('Disallowed /.. segment in URL'))
+
+    // File to URL mapping
+
+    itMapsFile(mapper, 'an HTML file',
+      { path: `${rootPath}space/foo.html` },
+      {
+        url: 'http://localhost/space/foo.html',
+        contentType: 'text/html'
+      })
+
+    itMapsFile(mapper, 'a Turtle file',
+      { path: `${rootPath}space/foo.ttl` },
+      {
+        url: 'http://localhost/space/foo.ttl',
+        contentType: 'text/turtle'
+      })
+
+    itMapsFile(mapper, 'an unknown file type',
+      { path: `${rootPath}space/foo.bar` },
+      {
+        url: 'http://localhost/space/foo.bar',
+        contentType: 'application/octet-stream'
+      })
+
+    itMapsFile(mapper, 'an extensionless HTML file',
+      { path: `${rootPath}space/foo$.html` },
+      {
+        url: 'http://localhost/space/foo',
+        contentType: 'text/html'
+      })
+
+    itMapsFile(mapper, 'an extensionless Turtle file',
+      { path: `${rootPath}space/foo$.ttl` },
+      {
+        url: 'http://localhost/space/foo',
+        contentType: 'text/turtle'
+      })
+
+    itMapsFile(mapper, 'an extensionless unknown file type',
+      { path: `${rootPath}space/foo$.bar` },
+      {
+        url: 'http://localhost/space/foo',
+        contentType: 'application/octet-stream'
+      })
   })
 })
 
@@ -154,3 +200,10 @@ function mapsUrl (it, mapper, label, options, files, expected) {
     })
   }
 }
+
+function mapsFile (it, mapper, label, options, expected) {
+  it(`maps ${label}`, async () => {
+    const actual = await mapper.mapFileToUrl(options)
+    expect(actual).to.deep.equal(expected)
+  })
+}