Add support for $nor to the Mongoid matcher. (#4552)

Author: saghm

lib/mongoid/matchable.rb

@@ -11,6 +11,7 @@
 require "mongoid/matchable/ne"
 require "mongoid/matchable/nin"
 require "mongoid/matchable/or"
+require "mongoid/matchable/nor"
 require "mongoid/matchable/size"
 require "mongoid/matchable/elem_match"
 require "mongoid/matchable/regexp"
@@ -40,6 +41,7 @@ module Matchable
       "$ne" => Ne,
       "$nin" => Nin,
       "$or" => Or,
+      "$nor" => Nor,
       "$size" => Size
     }.with_indifferent_access.freeze
 
@@ -124,6 +126,7 @@ def matcher(document, key, value)
           case key.to_s
             when "$or" then Or.new(value, document)
             when "$and" then And.new(value, document)
+            when "$nor" then Nor.new(value, document)
             else Default.new(extract_attribute(document, key))
           end
         end

lib/mongoid/matchable/nor.rb

@@ -0,0 +1,37 @@
+# frozen_string_literal: true
+# encoding: utf-8
+module Mongoid
+  module Matchable
+
+    # Defines behavior for handling $nor expressions in embedded documents.
+    class Nor < Default
+
+      # Does the supplied query match the attribute?
+      #
+      # Note: an empty array as an argument to $nor is prohibited by
+      # MongoDB server. Mongoid does allow this and returns false in this case.
+      #
+      # @example Does this match?
+      #   matcher._matches?("$nor" => [ { field => value } ])
+      #
+      # @param [ Array ] conditions The or expression.
+      #
+      # @return [ true, false ] True if matches, false if not.
+      #
+      # @since 6.4.2/7.0.2/7.1.0
+      def _matches?(conditions)
+        if conditions.length == 0
+          # MongoDB does not allow $nor array to be empty, but
+          # Mongoid accepts an empty array for $or which MongoDB also
+          # prohibits
+          return false
+        end
+        conditions.none? do |condition|
+          condition.all? do |key, value|
+            document._matches?(key => value)
+          end
+        end
+      end
+    end
+  end
+end

spec/app/models/array_field.rb

@@ -0,0 +1,7 @@
+# frozen_string_literal: true
+
+class ArrayField
+  include Mongoid::Document
+
+  field :af, type: Array
+end

spec/mongoid/matchable/nor_spec.rb

@@ -0,0 +1,209 @@
+# frozen_string_literal: true
+
+require "spec_helper"
+
+describe Mongoid::Matchable::Nor do
+
+  let(:target) do
+    Person.new
+  end
+
+  let(:matcher) do
+    described_class.new("value", target)
+  end
+
+  describe "#_matches?" do
+
+    context "when provided a simple expression" do
+
+      context "when one of the hashes does not match model" do
+
+        let(:matches) do
+          matcher._matches?(
+            [ { title: "Sir" }, { title: "King" } ]
+          )
+        end
+
+        let(:target) do
+          Person.new(title: 'Queen')
+        end
+
+        it "returns true" do
+          expect(matches).to be true
+        end
+      end
+
+      context "when all of the hashes match different fields in model" do
+        let(:matches) do
+          matcher._matches?(
+            [ { age: 10 }, { title: "King" } ]
+          )
+        end
+
+        let(:target) do
+          Person.new(title: 'King', age: 10)
+        end
+
+        it "returns false" do
+          expect(matches).to be false
+        end
+      end
+
+      context "when one of the hashes matches an array field in model" do
+        let(:matches) do
+          matcher._matches?(
+            [ { af: "Sir" }, { af: "King" } ]
+          )
+        end
+
+        let(:target) do
+          ArrayField.new(af: ['King'])
+        end
+
+        it "returns false" do
+          expect(matches).to be false
+        end
+      end
+
+      context "when none of the hashes matches an array field in model" do
+        let(:matches) do
+          matcher._matches?(
+            [ { af: "Sir" }, { af: "King" } ]
+          )
+        end
+
+        let(:target) do
+          ArrayField.new(af: ['Boo'])
+        end
+
+        it "returns true" do
+          expect(matches).to be true
+        end
+      end
+
+      context "when there are no criteria" do
+
+        it "returns false" do
+          expect(matcher._matches?([])).to be false
+        end
+      end
+
+      # $nor with $not is a double negation.
+      # Whatever the argument of $not is is what the overall condition
+      # is looking for.
+      context "when the expression is a $not" do
+
+        let(:matches) do
+          matcher._matches?([ { title: {:$not => /Foobar/ } }])
+        end
+
+        context "when the value does not match $not argument" do
+
+          let(:target) do
+            Person.new(title: 'test')
+          end
+
+          it "returns false" do
+            expect(matches).to be false
+          end
+        end
+
+        context "when the value matches $not argument" do
+
+          let(:target) do
+            Person.new(title: 'Foobar baz')
+          end
+
+          it "returns true" do
+            expect(matches).to be true
+          end
+        end
+      end
+    end
+
+    context "when provided a complex expression" do
+
+      context "when none of the model values match criteria values" do
+
+        let(:matches) do
+          matcher._matches?(
+            [
+              { title: { "$in" => [ "Sir", "Madam" ] } },
+              { title: "King" }
+            ]
+          )
+        end
+
+        let(:target) do
+          Person.new(title: 'Queen')
+        end
+
+        it "returns true" do
+          expect(matches).to be true
+        end
+      end
+
+      context "when there is a matching value" do
+
+        let(:matches) do
+          matcher._matches?(
+            [
+              { title: { "$in" => [ "Prince", "Madam" ] } },
+              { title: "King" }
+            ]
+          )
+        end
+
+        let(:target) do
+          Person.new(title: 'Prince')
+        end
+
+        it "returns false" do
+          expect(matches).to be false
+        end
+      end
+
+      context "when expression contain multiple fields" do
+
+        let(:matches) do
+          matcher._matches?(
+            [
+              { title: "Sir", age: 23 },
+              { title: "King", age: 100 }
+            ]
+          )
+        end
+
+        context 'and model has different values in all of the fields' do
+          let(:target) do
+            Person.new(title: 'Queen', age: 10)
+          end
+
+          it "returns true" do
+            expect(matches).to be true
+          end
+        end
+
+        context 'and model has identical value in one of the fields' do
+          let(:target) do
+            Person.new(title: 'Queen', age: 23)
+          end
+
+          it "returns true" do
+            expect(matches).to be true
+          end
+        end
+
+        context 'and model has identical values in all of the fields' do
+          let(:target) do
+            Person.new(title: 'Sir', age: 23)
+          end
+
+          it "returns false" do
+            expect(matches).to be false
+          end
+        end
+      end
+    end
+  end
+end

spec/mongoid/matchable_spec.rb

@@ -86,7 +86,7 @@
           let(:selector) do
             { "occupants.0" => "Tim" }
           end
-          
+
           it "returns true" do
             expect(document.locations.first._matches?(selector)).to be true
           end
@@ -774,6 +774,31 @@
         end
       end
 
+      context "with an $nor selector" do
+
+        context "when the attributes match" do
+
+          let(:selector) do
+            { "$nor" => [ { number: 10 }, { number: { "$gt" => 199 } } ] }
+          end
+
+          it "returns true" do
+            expect(document._matches?(selector)).to be true
+          end
+        end
+
+        context "when the attributes do not match" do
+
+          let(:selector) do
+            { "$nor" => [ { number: 10 }, { number: { "$gt" => 99 } } ] }
+          end
+
+          it "returns false" do
+            expect(document._matches?(selector)).to be false
+          end
+        end
+      end
+
       context "with a $size selector" do
 
         context "when the attributes match" do