Merge pull request #113 from DiannaHohensee/MONGOID-3639

MONGOID-3639 add merging of selectors with either '$nor' or '$nin' operators, rather than overwriting

lib/origin/selector.rb

@@ -18,7 +18,9 @@ class Selector < Smash
     def merge!(other)
       other.each_pair do |key, value|
         if value.is_a?(Hash) && self[key.to_s].is_a?(Hash)
-          value = self[key.to_s].merge(value)
+          value = self[key.to_s].merge(value) do |_key, old_val, new_val|
+            multi_value?(_key) ? (old_val + new_val).uniq : new_val
+          end
         end
         if multi_selection?(key)
           value = (self[key.to_s] || []).concat(value)
@@ -154,7 +156,7 @@ def evolve_hash(serializer, value)
       end
     end
 
-    # Determines if the selection is a multi-select, like an $and or $or
+    # Determines if the selection is a multi-select, like an $and or $or or $nor
     # selection.
     #
     # @api private
@@ -168,7 +170,23 @@ def evolve_hash(serializer, value)
     #
     # @since 1.0.0
     def multi_selection?(key)
-      key =~ /\$and|\$or/
+      key =~ /\$and|\$or|\$nor/
+    end
+
+    # Determines if the selection operator takes a list. Returns true for $in and $nin.
+    #
+    # @api private
+    #
+    # @example Does the selection operator take multiple values?
+    #   selector.multi_value?("$nin")
+    #
+    # @param [ String ] key The key to check.
+    #
+    # @return [ true, false ] If the key is $in or $nin.
+    #
+    # @since 2.1.1
+    def multi_value?(key)
+      key =~ /\$nin|\$in/
     end
   end
 end

spec/origin/selectable_spec.rb

@@ -2520,7 +2520,7 @@ def localized?
 
       it "adds the $nor selector" do
         expect(selection.selector).to eq({
-          "$nor" => [{ field: [ 1, 2 ] }]
+          "$nor" => [{"field" => [ 1, 2 ] }]
         })
       end
 
@@ -2540,8 +2540,8 @@ def localized?
         it "adds the $nor selector" do
           expect(selection.selector).to eq({
             "$nor" => [
-              { first: [ 1, 2 ] },
-              { second: [ 3, 4 ] }
+              { "first" => [ 1, 2 ] },
+              { "second" => [ 3, 4 ] }
             ]
           })
         end
@@ -2560,8 +2560,8 @@ def localized?
         it "appends both $nor expressions" do
           expect(selection.selector).to eq({
             "$nor" => [
-              { first: [ 1, 2 ] },
-              { first: [ 3, 4 ] }
+              { "first" => [ 1, 2 ] },
+              { "first" => [ 3, 4 ] }
             ]
           })
         end
@@ -2583,8 +2583,8 @@ def localized?
         it "adds the $nor selectors" do
           expect(selection.selector).to eq({
             "$nor" => [
-              { first: [ 1, 2 ] },
-              { second: [ 3, 4 ] }
+              { "first" => [ 1, 2 ] },
+              { "second" => [ 3, 4 ] }
             ]
           })
         end
@@ -2603,8 +2603,8 @@ def localized?
         it "appends both $nor expressions" do
           expect(selection.selector).to eq({
             "$nor" => [
-              { first: [ 1, 2 ] },
-              { first: [ 3, 4 ] }
+              { "first" => [ 1, 2 ] },
+              { "first" => [ 3, 4 ] }
             ]
           })
         end

spec/origin/selector_spec.rb

@@ -42,6 +42,34 @@
       end
     end
 
+    context "when selector contains a $nin" do
+
+      let(:initial) do
+        { "$nin" => ["foo"] }
+      end
+
+      before do
+        selector["field"] = initial
+      end
+
+      context "when merging in a new $nin" do
+
+        let(:other) do
+          { "field" => { "$nin" => ["bar"] } }
+        end
+
+        before do
+          selector.merge!(other)
+        end
+
+        it "combines the two $nin queries into one" do
+          expect(selector).to eq({
+            "field" => { "$nin" => ["foo", "bar"] }
+          })
+        end
+      end
+    end
+
     context "when selector is not nested" do
 
       before do
@@ -117,6 +145,34 @@
         end
       end
     end
+
+    context "when the selector contains a $nor" do
+
+      let(:initial) do
+        [{ "value" => 1 }]
+      end
+
+      before do
+        selector["$nor"] = initial
+      end
+
+      context "when merging in a new $nor" do
+
+        let(:other) do
+          [{ "value" => 2 }]
+        end
+
+        before do
+          selector.merge!({ "$nor" => other })
+        end
+
+        it "combines the two $nor queries into one" do
+          expect(selector).to eq({
+            "$nor" => initial + other
+          })
+        end
+      end
+    end
   end
 
   describe "#__deep_copy__" do