Add ExampleFilter class

spec/example_filter_spec.cr

@@ -0,0 +1,85 @@
+require "./spec_helper"
+
+def new_filter(criterion)
+  criteria = ["BOGUS", -1, criterion, /^$/, Spectator::Source.new(__FILE__, __LINE__)]
+  Spectator::ExampleFilter.new(criteria)
+end
+
+describe Spectator::ExampleFilter do
+  describe "#includes?" do
+    context "with a matching Regex" do
+      it "is true" do
+        example = new_runnable_example
+        regex = Regex.new(Regex.escape(example.what))
+        filter = new_filter(regex)
+        filter.includes?(example).should be_true
+      end
+    end
+
+    context "with a non-matching Regex" do
+      it "is false" do
+        example = new_runnable_example
+        regex = /BOGUS/
+        filter = new_filter(regex)
+        filter.includes?(example).should be_false
+      end
+    end
+
+    context "with a String equal to the name" do
+      it "is true" do
+        example = new_runnable_example
+        filter = new_filter(example.to_s)
+        filter.includes?(example).should be_true
+      end
+    end
+
+    context "with a String different than the name" do
+      it "is false" do
+        example = new_runnable_example
+        filter = new_filter("FAKE")
+        filter.includes?(example).should be_false
+      end
+    end
+
+    context "with a matching source location" do
+      it "is true" do
+        example = new_runnable_example
+        filter = new_filter(example.source)
+        filter.includes?(example).should be_true
+      end
+    end
+
+    context "with a non-matching source location" do
+      it "is false" do
+        example = new_runnable_example
+        source = Spectator::Source.new(__FILE__, __LINE__)
+        filter = new_filter(source)
+        filter.includes?(example).should be_false
+      end
+    end
+
+    context "with a matching source line" do
+      it "is true" do
+        example = new_runnable_example
+        filter = new_filter(example.source.line)
+        filter.includes?(example).should be_true
+      end
+    end
+
+    context "with a non-matching source line" do
+      it "is false" do
+        example = new_runnable_example
+        line = example.source.line + 5
+        filter = new_filter(line)
+        filter.includes?(example).should be_false
+      end
+    end
+
+    context "with an empty criteria" do
+      it "is true" do
+        filter = Spectator::ExampleFilter.new
+        filter.includes?(new_runnable_example).should be_true
+      end
+    end
+  end
+end