add integrative tests for typed_value for booleans

first charge of tests.

I intend those to fail for postgres, but can't verify that locally, so travis
will have to do it for me.

If you see this build failing for the newly added specs: This is intentional!

spec/models/custom_value_spec.rb

@@ -0,0 +1,58 @@
+#-- copyright
+# OpenProject is a project management system.
+# Copyright (C) 2012-2015 the OpenProject Foundation (OPF)
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2013 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See doc/COPYRIGHT.rdoc for more details.
+#++
+
+require 'spec_helper'
+
+describe CustomValue do
+  let(:format) { 'bool' }
+  let(:custom_field) { FactoryGirl.create(:custom_field, field_format: format) }
+  subject { FactoryGirl.create(:custom_value, custom_field: custom_field, value: value) }
+
+  describe '#typed_value' do
+    before do
+      # we are testing the database-side integratively here
+      # databases might choose to store values in weird and unexpected formats (e.g. booleans)
+      subject.reload
+    end
+
+    describe 'boolean custom value' do
+      let(:format) { 'bool' }
+      let(:value) { true }
+
+      context 'is true' do
+        it { expect(subject.typed_value).to eql(true) }
+      end
+
+      context 'is false' do
+        let(:value) { false }
+
+        it { expect(subject.typed_value).to eql(false) }
+      end
+    end
+  end
+end