Fix const_get naming and write test for filter

Author: Kevin Paulisse

lib/octocatalog-diff/catalog-diff/filter.rb

@@ -22,14 +22,14 @@ def self.apply_filters(result, filter_names, options = {})
       # @param filter_class_name [String] Filter class name (from `filter` subdirectory)
       # @param options [Hash] Additional options (optional) to pass to filtered? method
       def self.filter(result, filter_class_name, options = {})
-        filter_class_name = [self.class.name.to_s, filter_class_name].join('::')
-        clazz = Kernel.get_const(filter_class_name)
+        filter_class_name = [name.to_s, filter_class_name].join('::')
+        clazz = Kernel.const_get(filter_class_name)
         result.reject! { |item| clazz.filtered?(item, options) }
       end
 
       # Inherited: Construct a default `filtered?` method for the subclass via inheritance.
       # Each subclass must implement this method, so the default method errors.
-      def self.filtered?(_item, _options)
+      def self.filtered?(_item, _options = {})
         raise "No `filtered?` method is implemented in #{self.class.name}"
       end
     end

spec/octocatalog-diff/tests/catalog-diff/filter_spec.rb

@@ -0,0 +1,41 @@
+# frozen_string_literal: true
+
+require_relative '../spec_helper'
+require OctocatalogDiff::Spec.require_path('/catalog-diff/filter')
+
+describe OctocatalogDiff::CatalogDiff::Filter do
+  before(:each) do
+    @class_1 = double
+    @class_2 = double
+    allow(Kernel).to receive(:const_get).with('OctocatalogDiff::CatalogDiff::Filter::Fake1').and_return(@class_1)
+    allow(Kernel).to receive(:const_get).with('OctocatalogDiff::CatalogDiff::Filter::Fake2').and_return(@class_2)
+  end
+
+  describe '#apply_filters' do
+    it 'should call self.filter() with appropriate options for each class' do
+      result = [false]
+      options = { 'Fake1' => { foo: 'bar' } }
+      classes = %w(Fake1 Fake2)
+      expect(@class_1).to receive(:'filtered?').with(false, foo: 'bar').and_return(false)
+      expect(@class_2).to receive(:'filtered?').with(false, {}).and_return(false)
+      expect { described_class.apply_filters(result, classes, options) }.not_to raise_error
+      expect(result).to eq([false])
+    end
+  end
+
+  describe '#filter' do
+    it 'should call .filtered?() in a class and remove matching items' do
+      result = [false, true]
+      expect(@class_1).to receive(:'filtered?').with(false, {}).and_return(false)
+      expect(@class_1).to receive(:'filtered?').with(true, {}).and_return(true)
+      expect { described_class.filter(result, 'Fake1') }.not_to raise_error
+      expect(result).to eq([false])
+    end
+  end
+
+  describe '#filtered?' do
+    it 'should raise error' do
+      expect { described_class.filtered?([]) }.to raise_error(RuntimeError, /No `filtered\?` method is implemented/)
+    end
+  end
+end