Get the best checksum URL possible

lib/solr_wrapper/checksum_validator.rb

@@ -25,13 +25,17 @@ def validate!(file)
     private
 
       def checksumurl(suffix)
-        if config.default_download_url == config.static_config.archive_download_url
-          "#{config.default_download_url}.#{suffix}"
+        if remote_checksum?(suffix)
+          config.checksum
         else
-          "http://www.us.apache.org/dist/lucene/solr/#{config.static_config.version}/solr-#{config.static_config.version}.zip.#{suffix}"
+          "http://archive.apache.org/dist/lucene/solr/#{config.static_config.version}/solr-#{config.static_config.version}.zip.#{suffix}"
         end
       end
 
+      def remote_checksum?(alg)
+        config.checksum && config.checksum.match(/http.*#{alg}/, 0)
+      end
+
       def checksum_path(suffix)
         File.join(config.download_dir, File.basename(checksumurl(suffix)))
       end

spec/lib/solr_wrapper/checksum_validator_spec.rb

@@ -0,0 +1,26 @@
+require 'spec_helper'
+
+RSpec.describe SolrWrapper::ChecksumValidator do
+  let(:validator) { described_class.new(settings) }
+  let(:settings) { SolrWrapper::Settings.new(config) }
+  let(:config) { SolrWrapper::Configuration.new(options) }
+
+  describe '#checksumurl' do
+    subject { validator.send(:checksumurl, described_class::ALGORITHM) }
+
+    context 'when the checksum option is not set' do
+      let(:options) { { version: '6.6.0'} }
+      it { is_expected.to eq 'http://archive.apache.org/dist/lucene/solr/6.6.0/solr-6.6.0.zip.sha1' }
+    end
+
+    context 'when the checksum option is not a URL' do
+      let(:options) { { version: '6.6.1', checksum: './just/a/path.sha1'} }
+      it { is_expected.to eq 'http://archive.apache.org/dist/lucene/solr/6.6.1/solr-6.6.1.zip.sha1' }
+    end
+
+    context 'when the checksum option is a URL' do
+      let(:options) { { version: '6.6.2', checksum: 'http://lib-solr-mirror.princeton.edu/dist/lucene/solr/6.6.2/solr-6.6.2.zip.sha1'} }
+      it { is_expected.to eq 'http://lib-solr-mirror.princeton.edu/dist/lucene/solr/6.6.2/solr-6.6.2.zip.sha1' }
+    end
+  end
+end