Merge pull request #953 from alphagov/simplify-download-logic

Simplify download link logic

docs/documentation_routes.js

@@ -7,9 +7,6 @@ const express = require('express')
 const marked = require('marked')
 const router = express.Router()
 
-// Local dependencies
-const utils = require('../lib/utils.js')
-
 // Page routes
 
 // Docs index
@@ -34,10 +31,24 @@ router.get('/install/:page', function (req, res) {
   res.render('install_template', { document: html })
 })
 
-// Redirect to the zip of the latest release of the Prototype Kit on GitHub
+// When in 'promo mode', redirect to download the current release zip from
+// GitHub, based on the version number from package.json
+//
+// Otherwise, redirect to the latest release page on GitHub, to avoid just
+// linking to the same version being run by someone referring to the copy of the
+// docs running in their kit
 router.get('/download', function (req, res) {
-  var url = utils.getLatestRelease()
-  res.redirect(url)
+  if (req.app.locals.promoMode === 'true') {
+    const version = require('../package.json').version
+
+    res.redirect(
+      `https://github.com/alphagov/govuk-prototype-kit/archive/v${version}.zip`
+    )
+  } else {
+    res.redirect(
+      'https://github.com/alphagov/govuk-prototype-kit/releases/latest'
+    )
+  }
 })
 
 // Examples - examples post here

lib/utils.js

@@ -7,14 +7,10 @@ const marked = require('marked')
 const path = require('path')
 const portScanner = require('portscanner')
 const inquirer = require('inquirer')
-const request = require('sync-request')
 
 // Local dependencies
 const config = require('../app/config.js')
 
-// Variables
-var releaseUrl = null
-
 // Require core and custom filters, merges to one object
 // and then add the methods to Nunjucks environment
 exports.addNunjucksFilters = function (env) {
@@ -131,38 +127,6 @@ exports.forceHttps = function (req, res, next) {
   next()
 }
 
-// Synchronously get the URL for the latest release on GitHub and cache it
-exports.getLatestRelease = function () {
-  if (releaseUrl !== null) {
-    // Release URL already exists
-    console.log('Release url cached:', releaseUrl)
-    return releaseUrl
-  } else {
-    // Release URL doesn't exist
-    try {
-      console.log('Getting latest release from GitHub')
-
-      var res = request(
-        'GET',
-        'https://api.github.com/repos/alphagov/govuk-prototype-kit/releases/latest',
-        {
-          headers: { 'user-agent': 'node.js' }
-        }
-      )
-      var data = JSON.parse(res.getBody('utf8'))
-
-      // Cache releaseUrl before we return it
-      releaseUrl = `https://github.com/alphagov/govuk-prototype-kit/archive/${data.name}.zip`
-
-      console.log('Release URL is', releaseUrl)
-      return releaseUrl
-    } catch (err) {
-      console.log("Couldn't retrieve release URL")
-      return 'https://github.com/alphagov/govuk-prototype-kit/releases/latest'
-    }
-  }
-}
-
 // Try to match a request to a template, for example a request for /test
 // would look for /app/views/test.html
 // and /app/views/test/index.html