Add specs for **nil parameter in methods/procs/lambdas

Author: eregon

language/lambda_spec.rb

@@ -286,6 +286,24 @@ def a; 1; end
       end
     end
   end
+
+  evaluate <<-ruby do
+    @a = -> (**nil) { :ok }
+    ruby
+
+    @a.call().should == :ok
+    -> { @a.call(a: 1) }.should raise_error(ArgumentError, 'no keywords accepted')
+    -> { @a.call(**{a: 1}) }.should raise_error(ArgumentError, 'no keywords accepted')
+    -> { @a.call("a" => 1) }.should raise_error(ArgumentError, 'no keywords accepted')
+  end
+
+  evaluate <<-ruby do
+    @a = -> (a, **nil) { a }
+    ruby
+
+    @a.call({a: 1}).should == {a: 1}
+    -> { @a.call(a: 1) }.should raise_error(ArgumentError, 'no keywords accepted')
+  end
 end
 
 describe "A lambda expression 'lambda { ... }'" do
@@ -583,5 +601,23 @@ def m2() yield end
       result = @a.(1, 2, e: 3, g: 4, h: 5, i: 6, &(l = ->{}))
       result.should == [1, 1, [], 2, 3, 2, 4, { h: 5, i: 6 }, l]
     end
+
+    evaluate <<-ruby do
+      @a = lambda { |**nil| :ok }
+      ruby
+
+      @a.call().should == :ok
+      -> { @a.call(a: 1) }.should raise_error(ArgumentError, 'no keywords accepted')
+      -> { @a.call(**{a: 1}) }.should raise_error(ArgumentError, 'no keywords accepted')
+      -> { @a.call("a" => 1) }.should raise_error(ArgumentError, 'no keywords accepted')
+    end
+
+    evaluate <<-ruby do
+      @a = lambda { |a, **nil| a }
+      ruby
+
+      @a.call({a: 1}).should == {a: 1}
+      -> { @a.call(a: 1) }.should raise_error(ArgumentError, 'no keywords accepted')
+    end
   end
 end

language/method_spec.rb

@@ -1100,6 +1100,16 @@ def m(a, b=1, *c, d, e:, f: 2, g:, **k, &l)
       result.should == [1, 1, [], 2, 3, 2, 4, { h: 5, i: 6 }, l]
     end
 
+    evaluate <<-ruby do
+      def m(**nil); :ok; end;
+      ruby
+
+      m().should == :ok
+      -> { m(a: 1) }.should raise_error(ArgumentError, 'no keywords accepted')
+      -> { m(**{a: 1}) }.should raise_error(ArgumentError, 'no keywords accepted')
+      -> { m("a" => 1) }.should raise_error(ArgumentError, 'no keywords accepted')
+    end
+
     evaluate <<-ruby do
       def m(a, **nil); a end;
       ruby

language/proc_spec.rb

@@ -246,4 +246,22 @@
       -> { p.call() }.should raise_error(ArgumentError)
     end
   end
+
+  evaluate <<-ruby do
+    @p = proc { |**nil| :ok }
+    ruby
+
+    @p.call().should == :ok
+    -> { @p.call(a: 1) }.should raise_error(ArgumentError, 'no keywords accepted')
+    -> { @p.call(**{a: 1}) }.should raise_error(ArgumentError, 'no keywords accepted')
+    -> { @p.call("a" => 1) }.should raise_error(ArgumentError, 'no keywords accepted')
+  end
+
+  evaluate <<-ruby do
+    @p = proc { |a, **nil| a }
+    ruby
+
+    @p.call({a: 1}).should == {a: 1}
+    -> { @p.call(a: 1) }.should raise_error(ArgumentError, 'no keywords accepted')
+  end
 end