Merge pull request #1479 from nevinera/nev--1478--include-with-no-args-should-fail

Require an argument for the Include matcher

Author: JonRowe

Changelog.md

@@ -7,6 +7,7 @@ Bug Fixes:
   (Eric Mueller, #1455)
 * Use `RSpec.warning` for an expectation warning rather than `Kernel.warn`. (Jon Rowe, #1472)
 * Prevent mismatched use of block and value matchers in compound expectations. (Phil Pirozhkov, #1476)
+* Raise an error when passing no arguments to the `include` matcher. (Eric Mueller, #1479)
 
 Enhancements:
 

lib/rspec/matchers/built_in/include.rb

@@ -13,6 +13,7 @@ class Include < BaseMatcher # rubocop:disable Metrics/ClassLength
 
         # @api private
         def initialize(*expecteds)
+          raise(ArgumentError, 'include() is not supported, please supply an argument') if expecteds.empty?
           @expecteds = expecteds
         end
 

spec/rspec/matchers/built_in/include_spec.rb

@@ -161,6 +161,12 @@ def hash.send; :sent; end
     end
   end
 
+  describe "expect(...).to include(with_no_args)" do
+    it "fails correctly" do
+      expect { expect([1, 2, 3]).to include }.to raise_error(ArgumentError)
+    end
+  end
+
   describe "expect(...).to include(with_one_arg)" do
     it_behaves_like "an RSpec value matcher", :valid_value => [1, 2], :invalid_value => [1] do
       let(:matcher) { include(2) }