methods on array subclass return array instance

[kuei0221]

HI, here is a spec for #823,

The following methods now return Array instances instead of
subclass instances when called on subclass instances:
[Bug #6087]

Array#drop
Array#drop_while
Array#flatten
Array#slice!
Array#slice / Array#[]
Array#take
Array#take_while
Array#uniq
Array#*

This PR will add spec to cover drop, drop_while, take, take_while, slice!
Other methods are already covered with spec:

Array#flatten

spec/core/array/flatten_spec.rb

Lines 78 to 96 in 7526ccb

	ruby_version_is ''...'3.0' do
	it "returns subclass instance for Array subclasses" do
	ArraySpecs::MyArray[].flatten.should be_an_instance_of(ArraySpecs::MyArray)
	ArraySpecs::MyArray[1, 2, 3].flatten.should be_an_instance_of(ArraySpecs::MyArray)
	ArraySpecs::MyArray[1, [2], 3].flatten.should be_an_instance_of(ArraySpecs::MyArray)
	ArraySpecs::MyArray[1, [2, 3], 4].flatten.should == ArraySpecs::MyArray[1, 2, 3, 4]
	[ArraySpecs::MyArray[1, 2, 3]].flatten.should be_an_instance_of(Array)
	end
	end
	ruby_version_is '3.0' do
	it "returns Array instance for Array subclasses" do
	ArraySpecs::MyArray[].flatten.should be_an_instance_of(Array)
	ArraySpecs::MyArray[1, 2, 3].flatten.should be_an_instance_of(Array)
	ArraySpecs::MyArray[1, [2], 3].flatten.should be_an_instance_of(Array)
	ArraySpecs::MyArray[1, [2, 3], 4].flatten.should == [1, 2, 3, 4]
	[ArraySpecs::MyArray[1, 2, 3]].flatten.should be_an_instance_of(Array)
	end
	end

Array#slice

spec/core/array/shared/slice.rb

Lines 393 to 450 in 7526ccb

	describe "with a subclass of Array" do
	before :each do
	ScratchPad.clear
	@array = ArraySpecs::MyArray[1, 2, 3, 4, 5]
	end
	ruby_version_is ''...'3.0' do
	it "returns a subclass instance with [n, m]" do
	@array.send(@method, 0, 2).should be_an_instance_of(ArraySpecs::MyArray)
	end
	it "returns a subclass instance with [-n, m]" do
	@array.send(@method, -3, 2).should be_an_instance_of(ArraySpecs::MyArray)
	end
	it "returns a subclass instance with [n..m]" do
	@array.send(@method, 1..3).should be_an_instance_of(ArraySpecs::MyArray)
	end
	it "returns a subclass instance with [n...m]" do
	@array.send(@method, 1...3).should be_an_instance_of(ArraySpecs::MyArray)
	end
	it "returns a subclass instance with [-n..-m]" do
	@array.send(@method, -3..-1).should be_an_instance_of(ArraySpecs::MyArray)
	end
	it "returns a subclass instance with [-n...-m]" do
	@array.send(@method, -3...-1).should be_an_instance_of(ArraySpecs::MyArray)
	end
	end
	ruby_version_is '3.0' do
	it "returns a Array instance with [n, m]" do
	@array.send(@method, 0, 2).should be_an_instance_of(Array)
	end
	it "returns a Array instance with [-n, m]" do
	@array.send(@method, -3, 2).should be_an_instance_of(Array)
	end
	it "returns a Array instance with [n..m]" do
	@array.send(@method, 1..3).should be_an_instance_of(Array)
	end
	it "returns a Array instance with [n...m]" do
	@array.send(@method, 1...3).should be_an_instance_of(Array)
	end
	it "returns a Array instance with [-n..-m]" do
	@array.send(@method, -3..-1).should be_an_instance_of(Array)
	end
	it "returns a Array instance with [-n...-m]" do
	@array.send(@method, -3...-1).should be_an_instance_of(Array)
	end
	end

Array#uniq

spec/core/array/uniq_spec.rb

Lines 131 to 141 in 7526ccb

	ruby_version_is ''...'3.0' do
	it "returns subclass instance on Array subclasses" do
	ArraySpecs::MyArray[1, 2, 3].uniq.should be_an_instance_of(ArraySpecs::MyArray)
	end
	end
	ruby_version_is '3.0' do
	it "returns Array instance on Array subclasses" do
	ArraySpecs::MyArray[1, 2, 3].uniq.should be_an_instance_of(Array)
	end
	end

Array#*

spec/core/array/multiply_spec.rb

Lines 79 to 93 in 7526ccb

	ruby_version_is ''...'3.0' do
	it "returns a subclass instance" do
	(@array * 0).should be_an_instance_of(ArraySpecs::MyArray)
	(@array * 1).should be_an_instance_of(ArraySpecs::MyArray)
	(@array * 2).should be_an_instance_of(ArraySpecs::MyArray)
	end
	end
	ruby_version_is '3.0' do
	it "returns an Array instance" do
	(@array * 0).should be_an_instance_of(Array)
	(@array * 1).should be_an_instance_of(Array)
	(@array * 2).should be_an_instance_of(Array)
	end
	end

Thanks 👍

[eregon]

Looks great, thank you!

Sorry for the late review.