Ruby 2.7: extend logic

spec/ruby/core/integer/element_reference_spec.rb

@@ -131,16 +131,10 @@
           0b000001[-3, 4].should == 0b1000
         end
 
-        it "ignores negative upper boundary" do
-          0b101001101[1..-1].should == 0b10100110
-          0b101001101[1..-2].should == 0b10100110
-          0b101001101[1..-3].should == 0b10100110
-        end
-
         it "ignores upper boundary smaller than lower boundary" do
           0b101001101[4..1].should == 0b10100
           0b101001101[4..2].should == 0b10100
-          0b101001101[4..3].should == 0b10100
+          0b101001101[-4..-5].should == 0b1010011010000
         end
 
         it "raises FloatDomainError if any boundary is infinity" do

src/main/ruby/truffleruby/core/integer.rb

@@ -88,20 +88,16 @@ def [](index, len = undefined)
       num = self >> range.begin
       mask = mask(range, len)
 
-      return num if range.end < 0
-      return num if range.end < range.begin
-      num & mask
+      range.end < range.begin ? num : num & mask
     elsif Primitive.nil? range.end
-      start = range.begin
 
-      return self >> start
+      return self >> range.begin
     else
       result = self & mask(range, range.end)
-      raise ArgumentError, 'The beginless range for Integer#[] results in infinity' if result != 0
+      raise ArgumentError, 'The beginless range for Integer#[] results in infinity' if result != 0 && range.end >= 0
 
-      result
+      0
     end
-
   end
 
   private def validate_range(index)

test/mri/excludes/TestInteger.rb

@@ -11,5 +11,4 @@
 exclude :test_floor, "needs investigation"
 exclude :test_pow, "needs investigation"
 exclude :test_truncate, "needs investigation"
-exclude :test_Integer_with_invalid_exception, "needs investigation"
-exclude :test_aref, "needs investigation"
+exclude :test_Integer_with_invalid_exception, "needs investigation"