(experimental) added framework for filtering all sorts of internals in discourse and consuming by plugins

spec/components/plugin/filter_manager_spec.rb

@@ -0,0 +1,35 @@
+require 'spec_helper'
+require_dependency 'plugin/filter_manager'
+
+describe Plugin::FilterManager do
+  let(:instance){ Plugin::FilterManager.new }
+
+  it "calls registered filters correctly" do
+    instance.register(:added_numbers) do |context,result|
+      context + result + 1
+    end
+
+    instance.register(:added_numbers) do |context,result|
+      context + result + 2
+    end
+
+    instance.apply(:added_numbers, 1, 0).should == 5
+  end
+
+  it "should raise an exception if wrong arity is passed in" do
+    lambda do
+      instance.register(:test) do
+      end
+    end.should raise_exception
+  end
+
+  it "should return the original if no filters exist" do
+    instance.apply(:foo, nil, 42).should == 42
+  end
+
+  it "should raise an exception if no block is passed in" do
+    lambda do
+      instance.register(:test)
+    end.should raise_exception
+  end
+end