Hardcode download URLs

When working on cucumber/cucumber-rails#378, we would sometimes see that the builds would be unable to connect to the Geckodriver. On further investigation, this seems to be caused by the Geckodriver not being downloaded in the first place. I think that this is due to GitHub's API rate limiting certain build machines from accessing their API.

A better approach would be to hardcode the URLs for the assets -- since they're easily predicatable -- and then to bump this gem whenever a new release comes out.

geckodriver-helper.gemspec

@@ -20,6 +20,7 @@ described by the WebDriver protocol to communicate with Gecko browsers, such as
 
   s.add_development_dependency "rspec",   "~> 3.0"
   s.add_development_dependency "rake",    "~> 10.0"
+  s.add_development_dependency "http",    "~> 3.0"
 
   s.add_runtime_dependency "archive-zip", "~> 0.7"
 end

lib/geckodriver/helper.rb

@@ -1,5 +1,4 @@
 require 'geckodriver/helper/version'
-require 'geckodriver/helper/gecko_release_page_parser'
 require 'fileutils'
 require 'rbconfig'
 require 'open-uri'
@@ -9,6 +8,7 @@
 
 module Geckodriver
   class Helper
+    DRIVER_VERSION = "v0.20.1".freeze
 
     def run *args
       download
@@ -48,15 +48,18 @@ def update
     end
 
     def download_url
-      GeckoReleasePageParser.new(platform).latest_release
+      extension = platform.include?('win') ? 'zip' : 'tar.gz'
+      "https://github.com/mozilla/geckodriver/releases/download/#{DRIVER_VERSION}/geckodriver-#{DRIVER_VERSION}-#{platform}.#{extension}"
     end
 
     def binary_path
-      if platform == 'win'
-        File.join platform_install_dir, 'geckodriver.exe'
-      else
-        File.join platform_install_dir, 'geckodriver'
-      end
+      exe = if platform.include?('win')
+              'geckodriver.exe'
+            else
+              'geckodriver'
+            end
+
+      File.join platform_install_dir, exe
     end
 
     def platform_install_dir
@@ -72,19 +75,25 @@ def install_dir
     end
 
     def platform
-      cfg = RbConfig::CONFIG
-      case cfg['host_os']
-        when /linux/ then
-          cfg['host_cpu'] =~ /x86_64|amd64/ ? 'linux64' : 'linux32'
-        when /darwin/ then
-          'mac'
+      @platform ||= begin
+        cfg = RbConfig::CONFIG
+        case cfg['host_os']
+        when /linux/
+          append_64_or_32('linux', cfg)
+        when /darwin/
+          'macos'
         else
-          'win'
+          append_64_or_32('win', cfg)
+        end
       end
     end
 
     private
 
+    def append_64_or_32(platform)
+      cfg['host_cpu'] =~ /x86_64|amd64/ ? "#{platform}64" : "#{platform}32"
+    end
+
     def unzip(zipfile)
       Archive::Zip.extract(zipfile, '.', :overwrite => :all)
     end
@@ -106,6 +115,5 @@ def untar(io)
         end
       end
     end
-
   end
 end

lib/geckodriver/helper/version.rb

@@ -1,5 +1,5 @@
 module Geckodriver
   class Helper
-    VERSION = '0.0.5'
+    VERSION = '0.20.1'
   end
 end

spec/helper_spec.rb

@@ -1,21 +1,46 @@
 require 'spec_helper'
+require 'http'
 
 describe Geckodriver::Helper do
   let(:helper) { Geckodriver::Helper.new }
 
+  RSpec::Matchers.define :be_reachable do
+    match do |download_url|
+      response = HTTP.head download_url
+      location = response["Location"]
+      expect(response["Location"]).to include("github-production-release-asset")
+      expect(response["Location"]).to include("s3.amazonaws.com")
+    end
+  end
+
   describe '#binary_path' do
-    context 'on a linux platform' do
+    context 'on a linux32 platform' do
       before { allow(helper).to receive(:platform) { 'linux32' } }
+      it { expect(helper.download_url).to be_reachable }
+      it { expect(helper.binary_path).to match(/geckodriver$/) }
+    end
+
+    context 'on a linux64 platform' do
+      before { allow(helper).to receive(:platform) { 'linux64' } }
+      it { expect(helper.download_url).to be_reachable }
       it { expect(helper.binary_path).to match(/geckodriver$/) }
     end
 
     context 'on a mac platform' do
-      before { allow(helper).to receive(:platform) { 'mac' } }
+      before { allow(helper).to receive(:platform) { 'macos' } }
+      it { expect(helper.download_url).to be_reachable }
       it { expect(helper.binary_path).to match(/geckodriver$/) }
     end
 
-    context 'on a windows platform' do
-      before { allow(helper).to receive(:platform) { 'win' } }
+    context 'on a windows32 platform' do
+      before { allow(helper).to receive(:platform) { 'win32' } }
+      it { expect(helper.download_url).to be_reachable }
+      it { expect(helper.binary_path).to match(/geckodriver\.exe$/) }
+    end
+
+    context 'on a windows64 platform' do
+      before { allow(helper).to receive(:platform) { 'win64' } }
+      it { expect(helper.download_url).to be_reachable }
       it { expect(helper.binary_path).to match(/geckodriver\.exe$/) }
     end
   end