MONGOID-4914 Unmask Enumerable#find

lib/mongoid/criteria.rb

@@ -20,9 +20,11 @@ module Mongoid
   # against the database.
   class Criteria
     include Enumerable
+    alias :_enumerable_find :find
     include Contextual
     include Queryable
     include Findable
+    alias :_findable_find :find
     include Inspectable
     include Includable
     include Marshalable
@@ -55,6 +57,40 @@ def ==(other)
       entries == other
     end
 
+    # Call either Findable#find or Enumerable#find based on the given arguments
+    #
+    # If the arguments match Enumerable#find signature, that will be invoked.
+    # Otherwise Findable#find will be invoked
+    #
+    # The signature of Enumerable#find:
+    #
+    #   find(ifnone = nil) { |obj| block } → obj or nil
+    #   find(ifnone = nil) → an_enumerator
+    #
+    # @example Find using a block, invokes Enumerable#find
+    #   criteria.find { |item| item.name == "Depeche Mode" }
+    #
+    # @example Find given a block and a Proc, invokes Enumerable#find
+    #   criteria.find(-> { "Default Band" }) { |item| item.name == "Milwaukee Mode" }
+    #
+    # @example Find given just a Proc, invokes Enumerable#find, returns an Enumerator
+    #   enumerator = criteria.find(-> { "Default Band" })
+    #
+    # @example Find given anything else, invokes Findable#find
+    #   critera.find("1234")
+    #
+    # @return Same return value as either Findable#find or Enumerable#find, depending
+    #   on which one was invoked.
+    #
+    # @since 7.1.1
+    def find(*args, &block)
+      if block_given? || args.first&.is_a?(Proc)
+        _enumerable_find(*args, &block)
+      else
+        _findable_find(*args)
+      end
+    end
+
     # Needed to properly get a criteria back as json
     #
     # @example Get the criteria as json.

spec/mongoid/criteria_spec.rb

@@ -795,6 +795,44 @@
     end
   end
 
+  describe "#find" do
+    let!(:depeche) do
+      Band.create(name: "Depeche Mode")
+    end
+
+    let(:criteria) do
+      Band.where(name: "Depeche Mode")
+    end
+
+    context "when given a block" do
+      it "behaves as enumerable" do
+        result = criteria.find { |c| c.name == "Depeche Mode" }
+        expect(result).to eq(depeche)
+      end
+    end
+
+    context "when given a Proc and a block" do
+      it "behaves as enumerable" do
+        result = criteria.find(-> {"default"}) { |c| c.name == "Not Depeche Mode" }
+        expect(result).to eq("default")
+      end
+    end
+
+    context "when given a Proc" do
+      it "behaves as enumerable" do
+        result = criteria.find(-> {"default"})
+        expect(result).to be_a(Enumerator)
+      end
+    end
+
+    context "when given an id" do
+      it "behaves as findable" do
+        result = criteria.find(depeche.id)
+        expect(result).to eq(depeche)
+      end
+    end
+  end
+
   describe "#find_one_and_update" do
 
     let!(:depeche) do