1 files changed, 27 insertions, 10 deletions
diff --git a/spec/ruby/core/array/unshift_spec.rb b/spec/ruby/core/array/unshift_spec.rb
index 9467a1a6df..c190db4d02 100644
--- a/spec/ruby/core/array/unshift_spec.rb
+++ b/spec/ruby/core/array/unshift_spec.rb
@@ -1,12 +1,12 @@
-require File.expand_path('../../../spec_helper', __FILE__)
-require File.expand_path('../fixtures/classes', __FILE__)
+require_relative '../../spec_helper'
+require_relative 'fixtures/classes'
 
 describe "Array#unshift" do
   it "prepends object to the original array" do
     a = [1, 2, 3]
-    a.unshift("a").should equal(a)
+    a.unshift("a").should.equal?(a)
     a.should == ['a', 1, 2, 3]
-    a.unshift().should equal(a)
+    a.unshift.should.equal?(a)
     a.should == ['a', 1, 2, 3]
     a.unshift(5, 4, 3)
     a.should == [5, 4, 3, 'a', 1, 2, 3]
@@ -25,9 +25,13 @@ describe "Array#unshift" do
     a.should == [3, 4]
   end
 
+  it "returns self" do
+    a = [1, 2, 3]
+    a.unshift("a").should.equal?(a)
+  end
+
   it "quietly ignores unshifting nothing" do
-    [].unshift().should == []
-    [].unshift(*[]).should == []
+    [].unshift.should == []
   end
 
   it "properly handles recursive arrays" do
@@ -39,12 +43,25 @@ describe "Array#unshift" do
     array[0..5].should == [:new, 1, 'two', 3.0, array, array]
   end
 
-  it "raises a RuntimeError on a frozen array when the array is modified" do
-    lambda { ArraySpecs.frozen_array.unshift(1) }.should raise_error(RuntimeError)
+  it "raises a FrozenError on a frozen array when the array is modified" do
+    -> { ArraySpecs.frozen_array.unshift(1) }.should.raise(FrozenError)
   end
 
   # see [ruby-core:23666]
-  it "raises a RuntimeError on a frozen array when the array would not be modified" do
-    lambda { ArraySpecs.frozen_array.unshift    }.should raise_error(RuntimeError)
+  it "raises a FrozenError on a frozen array when the array would not be modified" do
+    -> { ArraySpecs.frozen_array.unshift }.should.raise(FrozenError)
+  end
+
+  # https://github.com/truffleruby/truffleruby/issues/2772
+  it "doesn't rely on Array#[]= so it can be overridden" do
+    subclass = Class.new(Array) do
+      def []=(*)
+        raise "[]= is called"
+      end
+    end
+
+    array = subclass.new
+    array.unshift(1)
+    array.should == [1]
   end
 end