Make circular argument reference a SyntaxError instead of a warning

Fixes [Bug #10314]

3 files changed, 85 insertions, 34 deletions

diff --git a/spec/ruby/language/block_spec.rb b/spec/ruby/language/block_spec.rb
index e5c9fcb762..6f92383af8 100644
--- a/spec/ruby/language/block_spec.rb
+++ b/spec/ruby/language/block_spec.rb
@@ -876,20 +876,38 @@ describe "Post-args" do
     end
 
     describe "with a circular argument reference" do
-      it "shadows an existing local with the same name as the argument" do
-        a = 1
-        -> {
-          @proc = eval "proc { |a=a| a }"
-        }.should complain(/circular argument reference/)
-        @proc.call.should == nil
+      ruby_version_is ''...'2.7' do
+        it "warns and uses a nil value when there is an existing local variable with same name" do
+          a = 1
+          -> {
+            @proc = eval "proc { |a=a| a }"
+          }.should complain(/circular argument reference/)
+          @proc.call.should == nil
+        end
+
+        it "warns and uses a nil value when there is an existing method with same name" do
+          def a; 1; end
+          -> {
+            @proc = eval "proc { |a=a| a }"
+          }.should complain(/circular argument reference/)
+          @proc.call.should == nil
+        end
       end
 
-      it "shadows an existing method with the same name as the argument" do
-        def a; 1; end
-        -> {
-          @proc = eval "proc { |a=a| a }"
-        }.should complain(/circular argument reference/)
-        @proc.call.should == nil
+      ruby_version_is '2.7' do
+        it "raises a SyntaxError if using an existing local with the same name as the argument" do
+          a = 1
+          -> {
+            @proc = eval "proc { |a=a| a }"
+          }.should raise_error(SyntaxError)
+        end
+
+        it "raises a SyntaxError if there is an existing method with the same name as the argument" do
+          def a; 1; end
+          -> {
+            @proc = eval "proc { |a=a| a }"
+          }.should raise_error(SyntaxError)
+        end
       end
 
       it "calls an existing method with the same name as the argument if explicitly using ()" do
diff --git a/spec/ruby/language/def_spec.rb b/spec/ruby/language/def_spec.rb
index 82813bd36c..fc5693a2f0 100644
--- a/spec/ruby/language/def_spec.rb
+++ b/spec/ruby/language/def_spec.rb
@@ -177,17 +177,32 @@ describe "An instance method with a default argument" do
     foo(2,3,3).should == [2,3,[3]]
   end
 
-  it "shadows an existing method with the same name as the local" do
-    def bar
-      1
+  ruby_version_is ''...'2.7' do
+    it "warns and uses a nil value when there is an existing local method with same name" do
+      def bar
+        1
+      end
+      -> {
+        eval "def foo(bar = bar)
+          bar
+        end"
+      }.should complain(/circular argument reference/)
+      foo.should == nil
+      foo(2).should == 2
+    end
+  end
+
+  ruby_version_is '2.7' do
+    it "raises a syntaxError an existing method with the same name as the local variable" do
+      def bar
+        1
+      end
+      -> {
+        eval "def foo(bar = bar)
+          bar
+        end"
+      }.should raise_error(SyntaxError)
     end
-    -> {
-      eval "def foo(bar = bar)
-        bar
-      end"
-    }.should complain(/circular argument reference/)
-    foo.should == nil
-    foo(2).should == 2
   end
 
   it "calls a method with the same name as the local when explicitly using ()" do
diff --git a/spec/ruby/language/lambda_spec.rb b/spec/ruby/language/lambda_spec.rb
index 5fa7fa6bfa..ddd0b574b3 100644
--- a/spec/ruby/language/lambda_spec.rb
+++ b/spec/ruby/language/lambda_spec.rb
@@ -267,20 +267,38 @@ describe "A lambda literal -> () { }" do
     end
 
     describe "with circular optional argument reference" do
-      it "shadows an existing local with the same name as the argument" do
-        a = 1
-        -> {
-          @proc = eval "-> (a=a) { a }"
-        }.should complain(/circular argument reference/)
-        @proc.call.should == nil
+      ruby_version_is ''...'2.7' do
+        it "warns and uses a nil value when there is an existing local variable with same name" do
+          a = 1
+          -> {
+            @proc = eval "-> (a=a) { a }"
+          }.should complain(/circular argument reference/)
+          @proc.call.should == nil
+        end
+
+        it "warns and uses a nil value when there is an existing method with same name" do
+          def a; 1; end
+          -> {
+            @proc = eval "-> (a=a) { a }"
+          }.should complain(/circular argument reference/)
+          @proc.call.should == nil
+        end
       end
 
-      it "shadows an existing method with the same name as the argument" do
-        def a; 1; end
-        -> {
-          @proc = eval "-> (a=a) { a }"
-        }.should complain(/circular argument reference/)
-        @proc.call.should == nil
+      ruby_version_is '2.7' do
+        it "raises a SyntaxError if using an existing local with the same name as the argument" do
+          a = 1
+          -> {
+            @proc = eval "-> (a=a) { a }"
+          }.should raise_error(SyntaxError)
+        end
+
+        it "raises a SyntaxError if there is an existing method with the same name as the argument" do
+          def a; 1; end
+          -> {
+            @proc = eval "-> (a=a) { a }"
+          }.should raise_error(SyntaxError)
+        end
       end
 
       it "calls an existing method with the same name as the argument if explicitly using ()" do