proc.c: proc without block

* proc.c (proc_new): promoted lambda/proc/Proc.new with no block
  in a method called with a block to a warning/error.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@66772 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 19 insertions, 5 deletions

diff --git a/spec/ruby/core/kernel/proc_spec.rb b/spec/ruby/core/kernel/proc_spec.rb
index d9c09117e7..2c0e7988f9 100644
--- a/spec/ruby/core/kernel/proc_spec.rb
+++ b/spec/ruby/core/kernel/proc_spec.rb
@@ -36,14 +36,28 @@ describe "Kernel.proc" do
 end
 
 describe "Kernel#proc" do
-  it "uses the implicit block from an enclosing method" do
-    def some_method
-      proc
+  ruby_version_is ""..."2.7" do
+    it "uses the implicit block from an enclosing method" do
+      def some_method
+        proc
+      end
+
+      prc = some_method { "hello" }
+
+      prc.call.should == "hello"
     end
+  end
 
-    prc = some_method { "hello" }
+  ruby_version_is "2.7" do
+    it "can be created when called with no block" do
+      def some_method
+        proc
+      end
 
-    prc.call.should == "hello"
+      -> {
+        some_method { "hello" }
+      }.should complain(/tried to create Proc object without a block/)
+    end
   end
 
   it "needs to be reviewed for spec completeness"