Add numeral finder methods

lib/active_graph/node/query_methods.rb

@@ -11,14 +11,46 @@ def exists?(node_condition = nil)
         !!result
       end
 
-      # Returns the first node of this class, sorted by ID. Note that this may not be the first node created since Neo4j recycles IDs.
-      def first
-        self.query_as(:n).limit(1).order(n: primary_key).pluck(:n).first
+      # Returns the first node (or first N nodes if a parameter is supplied) of this class, sorted by ID.
+      # Note that this may not be the first node created since Neo4j recycles IDs.
+      def first(limit = 1)
+        find_nth(0, limit)
       end
 
-      # Returns the last node of this class, sorted by ID. Note that this may not be the first node created since Neo4j recycles IDs.
-      def last
-        self.query_as(:n).limit(1).order(n: {primary_key => :desc}).pluck(:n).first
+      # Returns the last node (or last N nodes if a parameter is supplied) of this class, sorted by ID.
+      # Note that this may not be the first node created since Neo4j recycles IDs.
+      def last(limit = 1)
+        find_nth_from_last(0, limit)
+      end
+
+      # Returns the second node of this class, sorted by ID. Note that this may not be the first node created since Neo4j recycles IDs.
+      def second
+        find_nth(1)
+      end
+
+      # Returns the third node of this class, sorted by ID. Note that this may not be the first node created since Neo4j recycles IDs.
+      def third
+        find_nth(2)
+      end
+
+      # Returns the fourth node of this class, sorted by ID. Note that this may not be the first node created since Neo4j recycles IDs.
+      def fourth
+        find_nth(3)
+      end
+
+      # Returns the fifth node of this class, sorted by ID. Note that this may not be the first node created since Neo4j recycles IDs.
+      def fifth
+        find_nth(4)
+      end
+
+      # Returns the third to last node of this class, sorted by ID. Note that this may not be the first node created since Neo4j recycles IDs.
+      def third_to_last
+        find_nth_from_last(2)
+      end
+
+      # Returns the second to last node of this class, sorted by ID. Note that this may not be the first node created since Neo4j recycles IDs.
+      def second_to_last
+        find_nth_from_last(1)
       end
 
       # @return [Integer] number of nodes of this class
@@ -63,6 +95,18 @@ def exists_query_start(node_condition)
           self.query_as(:n)
         end
       end
+
+      def find_nth(index, limit = 1, order = primary_key)
+        if limit == 1
+          self.query_as(:n).order(n: order).limit(limit).skip(index).pluck(:n).first
+        else
+          self.query_as(:n).order(n: order).limit(limit).skip(index).pluck(:n).first(limit)
+        end
+      end
+
+      def find_nth_from_last(index, limit = 1)
+        find_nth(index, limit, {primary_key => :desc})
+      end
     end
   end
 end

spec/e2e/query_proxy_methods_spec.rb

@@ -177,11 +177,21 @@ def destroy_called
     end
   end
 
-  describe 'first and last' do
+  describe 'numeral finder methods (first, last, etc.)' do
     it 'returns different objects' do
-      Student.create
+      5.times { Student.create }
       expect(Student.all.count).to be > 1
       expect(Student.all.first).to_not eq(Student.all.last)
+      expect(Student.all.second).to_not eq(Student.all.second_to_last)
+      expect(Student.all.third).to_not eq(Student.all.third_to_last)
+      expect(Student.all.fourth).to_not eq(Student.all.fifth)
+    end
+
+    it 'allows to specify limit for first and last methods' do
+      Student.create
+      expect(Student.all.count).to be > 1
+      expect(Student.first(2)).to eq([Student.all.first, Student.all.second])
+      expect(Student.last(2)).to eq([Student.all.last, Student.all.second_to_last])
     end
 
     it 'returns objects across multiple associations' do