Add Array#slice! positive length check and spec

rubinius · Feb 20, 2015 · 7e71609 · 7e71609
1 parent 4417909
commit 7e71609
Show file tree

Hide file tree

Showing 2 changed files with 8 additions and 1 deletion.
diff --git a/kernel/common/array.rb b/kernel/common/array.rb
@@ -1580,7 +1580,8 @@ def slice!(start, length=undefined)
       end
     else
       start = Rubinius::Type.coerce_to_collection_index start
-      length = Rubinius::Type.coerce_to_collection_index length
+      length = Rubinius::Type.coerce_to_collection_length length
+      return nil if length < 0
 
       out = self[start, length]
 

diff --git a/spec/ruby/core/array/slice_spec.rb b/spec/ruby/core/array/slice_spec.rb
@@ -39,6 +39,12 @@
     a.should == []
   end
 
+  it "returns nil if length is negative" do
+    a = [1, 2, 3]
+    a.slice!(2, -1).should == nil
+    a.should == [1, 2, 3]
+  end
+
   it "properly handles recursive arrays" do
     empty = ArraySpecs.empty_recursive_array
     empty.slice(0).should == empty