Refactor Blacklight::Document#has? for clarity

lib/blacklight/document.rb

@@ -80,21 +80,29 @@ def _read_attribute(attr)
   # doc.has?(:location_facet, 'Clemons')
   # doc.has?(:id, 'h009', /^u/i)
   def has?(k, *values)
-    return true if key?(k) and values.empty?
-    return false if self[k].nil?
-    target = self[k]
-    if target.is_a?(Array)
-      values.each do |val|
-        return target.any?{|tv| val.is_a?(Regexp) ? (tv =~ val) : (tv==val)}
-      end
+    if !key?(k)
+      false
+    elsif values.empty?
+      self[k].present?
     else
-      return values.any? {|val| val.is_a?(Regexp) ? (target =~ val) : (target == val)}
+      Array(values).any? do |expected|
+        Array(self[k]).any? do |actual|
+          case expected
+          when Regexp
+            actual =~ expected
+          else
+            actual == expected
+          end
+        end
+      end
     end
   end
+  alias_method :has_field?, :has?
 
   def key? k
     _source.key? k
   end
+  alias_method :has_key?, :key?
 
   # helper
   # key is the name of the field

spec/lib/blacklight/document_spec.rb

@@ -0,0 +1,62 @@
+require 'spec_helper'
+
+describe Blacklight::Document do
+  let(:data) { {} }
+  subject do
+    Class.new do
+      include Blacklight::Document
+    end.new(data)
+  end
+
+  describe "#has?" do
+    context "without value constraints" do
+      it "should have the field if the field is in the data" do
+        data[:x] = true
+        expect(subject).to have_field(:x)
+      end
+
+      it "should not have the field if the field is not in the data" do
+        expect(subject).not_to have_field(:x)
+      end
+    end
+
+    context "with regular value constraints" do
+      it "should have the field if the data has that value" do
+        data[:x] = true
+        expect(subject).to have_field(:x, true)
+      end
+
+      it "should not have the field if the data does not have that value" do
+        data[:x] = false
+        expect(subject).not_to have_field(:x, true)
+      end
+
+      it "should allow multiple value constraints" do
+        data[:x] = false
+        expect(subject).to have_field(:x, true, false)
+      end
+
+      it "should support multivalued fields" do
+        data[:x] = ["a", "b", "c"]
+        expect(subject).to have_field(:x, "a")
+      end
+
+      it "should support multivalued fields with an array of value constraints" do
+        data[:x] = ["a", "b", "c"]
+        expect(subject).to have_field(:x, "a", "d")
+      end
+    end
+
+    context "with regexp value constraints" do
+      it "should check if the data matches the constraint" do
+        data[:x] = "the quick brown fox"
+        expect(subject).to have_field(:x, /fox/)
+      end
+
+      it "should support multivalued fields" do
+        data[:x] = ["the quick brown fox", "and the lazy dog"]
+        expect(subject).to have_field(:x, /fox/)
+      end
+    end
+  end
+end