Add test for basic behaviour

test/fetch_multi_by_test.rb

@@ -0,0 +1,61 @@
+require "test_helper"
+
+class FetchMultiByTest < IdentityCache::TestCase
+  NAMESPACE = IdentityCache::CacheKeyGeneration::DEFAULT_NAMESPACE
+
+  def setup
+    super
+    @bob = Item.new
+    @bob.id = 1
+    @bob.title = 'bob'
+
+    @bertha = Item.new
+    @bertha.id = 2
+    @bertha.title = 'bertha'
+  end
+
+  def test_fetch_multi_by_cache_key
+    Item.cache_index :title, unique: false
+
+    @bob.save!
+    @bertha.save!
+
+    assert_equal [@bob], Item.fetch_by_title('bob')
+
+    assert_equal [@bob, @bertha], Item.fetch_multi_by_title(['bob', 'bertha'])
+  end
+
+  def test_fetch_multi_by_unique_cache_key
+    Item.cache_index :title, unique: true
+
+    @bob.save!
+    @bertha.save!
+
+    assert_equal @bob, Item.fetch_by_title('bob')
+
+    assert_equal [@bob, @bertha], Item.fetch_multi_by_title(['bob', 'bertha'])
+  end
+
+  def test_fetch_multi_attribute_by_cache_key
+    Item.cache_attribute :title, by: :id, unique: false
+
+    @bob.save!
+    @bertha.save!
+
+    assert_equal ['bob'], Item.fetch_title_by_id(1)
+
+    assert_equal({ 1 => ['bob'], 2 => ['bertha'] }, Item.fetch_multi_title_by_id([1, 2]))
+  end
+
+
+  def test_fetch_multi_attribute_by_unique_cache_key
+    Item.cache_attribute :title, by: :id, unique: true
+
+    @bob.save!
+    @bertha.save!
+
+    assert_equal 'bob', Item.fetch_title_by_id(1)
+
+    assert_equal({ 1 => 'bob', 2 => 'bertha' }, Item.fetch_multi_title_by_id([1, 2]))
+  end
+end