Basic specs for XPath::Evaluator.

These currently only cover very simple XPath expressions.

spec/oga/xpath/evaluator/paths_spec.rb

@@ -0,0 +1,65 @@
+require 'spec_helper'
+
+describe Oga::XPath::Evaluator do
+  before do
+    @document  = parse('<a><b></b><b></b></a>')
+    @evaluator = described_class.new(@document)
+  end
+
+  context 'absolute paths' do
+    before do
+      @set = @evaluator.evaluate('/a')
+    end
+
+    example 'return a NodeSet instance' do
+      @set.is_a?(Oga::XML::NodeSet).should == true
+    end
+
+    example 'return the right amount of nodes' do
+      @set.length.should == 1
+    end
+
+    example 'return the correct nodes' do
+      @set[0].should == @document.children[0]
+    end
+  end
+
+  context 'relative paths' do
+    before do
+      @set = @evaluator.evaluate('a')
+    end
+
+    example 'return a NodeSet instance' do
+      @set.is_a?(Oga::XML::NodeSet).should == true
+    end
+
+    example 'return the right amount of nodes' do
+      @set.length.should == 1
+    end
+
+    example 'return the correct nodes' do
+      @set[0].should == @document.children[0]
+    end
+  end
+
+  context 'nested paths' do
+    before do
+      @set = @evaluator.evaluate('/a/b')
+    end
+
+    example 'return a NodeSet instance' do
+      @set.is_a?(Oga::XML::NodeSet).should == true
+    end
+
+    example 'return the right amount of rows' do
+      @set.length.should == 2
+    end
+
+    example 'return the correct nodes' do
+      a = @document.children[0]
+
+      @set[0].should == a.children[0]
+      @set[1].should == a.children[1]
+    end
+  end
+end