Merge pull request #44 from Sage/add-index-up-to-date-helper

PF: Add helper method to check if index is up to date

lib/mysql_framework/scripts/base.rb

@@ -50,6 +50,21 @@ def index_exists?(client, table_name, index_name)
         result.count >= 1
       end
 
+      def index_up_to_date?(client, table_name, index_name, columns)
+        result = client.query(<<~SQL)
+          SHOW INDEX FROM #{table_name} WHERE Key_name="#{index_name}";
+        SQL
+
+        return false if result.size != columns.size
+
+        index_columns = result.sort_by { |column| column[:Seq_in_index] }
+        index_columns.each_with_index do |column, i|
+          return false if column[:Column_name] != columns[i]
+        end
+
+        true
+      end
+
       protected
 
       def generate_partition_sql

lib/mysql_framework/version.rb

@@ -1,5 +1,5 @@
 # frozen_string_literal: true
 
 module MysqlFramework
-  VERSION = '2.1.5'
+  VERSION = '2.1.6'
 end

spec/lib/mysql_framework/scripts/base_spec.rb

@@ -86,4 +86,28 @@
       expect(subject.index_exists?(client,'foo','bar')).to eq(false)
     end
   end
+
+  describe '#index_up_to_date?' do
+    before do
+      expect(client).to receive(:query).and_return(
+        [{ Column_name: 'b', Seq_in_index: 2 }, { Column_name: 'a', Seq_in_index: 1 }]
+      )
+    end
+
+    it 'returns true when index is up to date' do
+      expect(subject.index_up_to_date?(client, 'foo', 'bar', ['a', 'b'])).to eq(true)
+    end
+
+    it 'returns false when index is missing a column' do
+      expect(subject.index_up_to_date?(client, 'foo', 'bar', ['a', 'b', 'c'])).to eq(false)
+    end
+
+    it 'returns false when index is having too many columns' do
+      expect(subject.index_up_to_date?(client, 'foo', 'bar', ['a'])).to eq(false)
+    end
+
+    it 'returns false when index has columns in wrong order' do
+      expect(subject.index_up_to_date?(client, 'foo', 'bar', ['b', 'a'])).to eq(false)
+    end
+  end
 end