1 files changed, 24 insertions, 2 deletions
diff --git a/spec/ruby/core/proc/parameters_spec.rb b/spec/ruby/core/proc/parameters_spec.rb
index e9bc9a1c57..ac8c6e3560 100644
--- a/spec/ruby/core/proc/parameters_spec.rb
+++ b/spec/ruby/core/proc/parameters_spec.rb
@@ -7,8 +7,8 @@ describe "Proc#parameters" do
 
   it "returns an Array of Arrays for a proc expecting parameters" do
     p = proc {|x| }
-    p.parameters.should be_an_instance_of(Array)
-    p.parameters.first.should be_an_instance_of(Array)
+    p.parameters.should.instance_of?(Array)
+    p.parameters.first.should.instance_of?(Array)
   end
 
   it "sets the first element of each sub-Array to :opt for optional arguments" do
@@ -158,4 +158,26 @@ describe "Proc#parameters" do
   it "returns :nokey for **nil parameter" do
     proc { |**nil| }.parameters.should == [[:nokey]]
   end
+
+  ruby_version_is "3.4"..."4.0" do
+    it "handles the usage of `it` as a parameter" do
+      eval("proc { it }").parameters.should == [[:opt, nil]]
+      eval("lambda { it }").parameters.should == [[:req]]
+    end
+  end
+
+  ruby_version_is "4.0" do
+    it "handles the usage of `it` as a parameter" do
+      eval("proc { it }").parameters.should == [[:opt]]
+      eval("lambda { it }").parameters.should == [[:req]]
+    end
+  end
+
+  ruby_version_is "4.1" do
+    it "returns :noblock for &nil parameter" do
+      eval <<~RUBY
+        proc { |&nil| }.parameters.should == [[:noblock]]
+      RUBY
+    end
+  end
 end