1 files changed, 95 insertions, 0 deletions
diff --git a/spec/ruby/core/array/shared/keep_if.rb b/spec/ruby/core/array/shared/keep_if.rb
new file mode 100644
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+++ b/spec/ruby/core/array/shared/keep_if.rb
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+require_relative '../../enumerable/shared/enumeratorized'
+require_relative '../shared/iterable_and_tolerating_size_increasing'
+
+describe :keep_if, shared: true do
+  it "deletes elements for which the block returns a false value" do
+    array = [1, 2, 3, 4, 5]
+    array.send(@method) {|item| item > 3 }.should equal(array)
+    array.should == [4, 5]
+  end
+
+  it "returns an enumerator if no block is given" do
+    [1, 2, 3].send(@method).should be_an_instance_of(Enumerator)
+  end
+
+  it "updates the receiver after all blocks" do
+    a = [1, 2, 3]
+    a.send(@method) do |e|
+      a.length.should == 3
+      false
+    end
+    a.length.should == 0
+  end
+
+  before :all do
+    @object = [1,2,3]
+  end
+  it_should_behave_like :enumeratorized_with_origin_size
+
+  describe "on frozen objects" do
+    before :each do
+      @origin = [true, false]
+      @frozen = @origin.dup.freeze
+    end
+
+    it "returns an Enumerator if no block is given" do
+      @frozen.send(@method).should be_an_instance_of(Enumerator)
+    end
+
+    describe "with truthy block" do
+      it "keeps elements after any exception" do
+        -> { @frozen.send(@method) { true } }.should raise_error(Exception)
+        @frozen.should == @origin
+      end
+
+      it "raises a FrozenError" do
+        -> { @frozen.send(@method) { true } }.should raise_error(FrozenError)
+      end
+    end
+
+    describe "with falsy block" do
+      it "keeps elements after any exception" do
+        -> { @frozen.send(@method) { false } }.should raise_error(Exception)
+        @frozen.should == @origin
+      end
+
+      it "raises a FrozenError" do
+        -> { @frozen.send(@method) { false } }.should raise_error(FrozenError)
+      end
+    end
+
+    it "raises a FrozenError on a frozen array only during iteration if called without a block" do
+      enum = @frozen.send(@method)
+      -> { enum.each {} }.should raise_error(FrozenError)
+    end
+  end
+
+  it "does not truncate the array is the block raises an exception" do
+    a = [1, 2, 3]
+    begin
+      a.send(@method) { raise StandardError, 'Oops' }
+    rescue
+    end
+
+    a.should == [1, 2, 3]
+  end
+
+  it "only changes elements before error is raised, keeping the element which raised an error." do
+    a = [1, 2, 3, 4]
+    begin
+      a.send(@method) do |e|
+        case e
+        when 2 then false
+        when 3 then raise StandardError, 'Oops'
+        else true
+        end
+      end
+    rescue StandardError
+    end
+
+    a.should == [1, 3, 4]
+  end
+
+  @value_to_return = -> _ { true }
+  it_should_behave_like :array_iterable_and_tolerating_size_increasing
+end