Calling find with nil should raise a proper exception

lib/mongoid/criteria.rb

@@ -298,7 +298,7 @@ def search(*args)
     #
     # @since 2.0.0
     def raise_invalid
-      raise Errors::InvalidOptions.new(:calling_document_find_with_nil_is_invalid, {})
+      raise Errors::InvalidFind.new
     end
 
     protected

lib/mongoid/errors.rb

@@ -5,6 +5,7 @@
 require "mongoid/errors/invalid_collection"
 require "mongoid/errors/invalid_database"
 require "mongoid/errors/invalid_field"
+require "mongoid/errors/invalid_find"
 require "mongoid/errors/invalid_options"
 require "mongoid/errors/invalid_type"
 require "mongoid/errors/mixed_relations"

lib/mongoid/errors/invalid_find.rb

@@ -0,0 +1,19 @@
+# encoding: utf-8
+module Mongoid #:nodoc
+  module Errors #:nodoc
+
+    # Raised when invalid arguments are passed to #find.
+    class InvalidFind < MongoidError
+
+      # Create the new invalid find error.
+      #
+      # @example Create the error.
+      #   InvalidFind.new
+      #
+      # @since 2.2.0
+      def initialize
+        super(translate("calling_document_find_with_nil_is_invalid", {}))
+      end
+    end
+  end
+end

spec/unit/mongoid/criteria_spec.rb

@@ -945,6 +945,15 @@
 
     context "with a single argument" do
 
+      context "when the arg is nil" do
+
+        it "adds the id selector" do
+          expect {
+            criteria.search(nil)
+          }.to raise_error(Mongoid::Errors::InvalidFind)
+        end
+      end
+
       context "when the arg is a string" do
 
         let(:id) do

spec/unit/mongoid/errors/invalid_find_spec.rb

@@ -0,0 +1,17 @@
+require "spec_helper"
+
+describe Mongoid::Errors::InvalidFind do
+
+  describe "#message" do
+
+    let(:error) do
+      described_class.new
+    end
+
+    it "returns the warning find with nil" do
+      error.message.should include(
+        "Calling Document#find with nil is invalid"
+      )
+    end
+  end
+end