[Strainer] Separate factory from template

test/unit/strainer_template_unit_test.rb

@@ -0,0 +1,82 @@
+# frozen_string_literal: true
+
+require 'test_helper'
+
+class StrainerTemplateUnitTest < Minitest::Test
+  include Liquid
+
+  def test_add_filter_when_wrong_filter_class
+    c = Context.new
+    s = c.strainer
+    wrong_filter = ->(v) { v.reverse }
+
+    exception = assert_raises(TypeError) do
+      s.class.add_filter(wrong_filter)
+    end
+    assert_equal(exception.message, "wrong argument type Proc (expected Module)")
+  end
+
+  module PrivateMethodOverrideFilter
+    private
+
+    def public_filter
+      "overriden as private"
+    end
+  end
+
+  def test_add_filter_raises_when_module_privately_overrides_registered_public_methods
+    strainer = Context.new.strainer
+
+    error = assert_raises(Liquid::MethodOverrideError) do
+      strainer.class.add_filter(PrivateMethodOverrideFilter)
+    end
+    assert_equal('Liquid error: Filter overrides registered public methods as non public: public_filter', error.message)
+  end
+
+  module ProtectedMethodOverrideFilter
+    protected
+
+    def public_filter
+      "overriden as protected"
+    end
+  end
+
+  def test_add_filter_raises_when_module_overrides_registered_public_method_as_protected
+    strainer = Context.new.strainer
+
+    error = assert_raises(Liquid::MethodOverrideError) do
+      strainer.class.add_filter(ProtectedMethodOverrideFilter)
+    end
+    assert_equal('Liquid error: Filter overrides registered public methods as non public: public_filter', error.message)
+  end
+
+  module PublicMethodOverrideFilter
+    def public_filter
+      "public"
+    end
+  end
+
+  def test_add_filter_does_not_raise_when_module_overrides_previously_registered_method
+    strainer = Context.new.strainer
+    with_global_filter do
+      strainer.class.add_filter(PublicMethodOverrideFilter)
+      assert(strainer.class.send(:filter_methods).include?('public_filter'))
+    end
+  end
+
+  def test_add_filter_does_not_include_already_included_module
+    mod = Module.new do
+      class << self
+        attr_accessor :include_count
+        def included(_mod)
+          self.include_count += 1
+        end
+      end
+      self.include_count = 0
+    end
+    strainer = Context.new.strainer
+    strainer.class.add_filter(mod)
+    strainer.class.add_filter(mod)
+    assert_equal(1, mod.include_count)
+  end
+end