require File.expand_path('../../../spec_helper', __FILE__) require File.expand_path('../fixtures/classes', __FILE__) require File.expand_path('../shared/iteration', __FILE__) require File.expand_path('../../enumerable/shared/enumeratorized', __FILE__) describe "Hash#keep_if" do it "yields two arguments: key and value" do all_args = [] { 1 => 2, 3 => 4 }.keep_if { |*args| all_args << args } all_args.should == [[1, 2], [3, 4]] end it "keeps every entry for which block is true and returns self" do h = { a: 1, b: 2, c: 3, d: 4 } h.keep_if { |k,v| v % 2 == 0 }.should equal(h) h.should == { b: 2, d: 4 } end it "removes all entries if the block is false" do h = { a: 1, b: 2, c: 3 } h.keep_if { |k,v| false }.should equal(h) h.should == {} end it "returns self even if unmodified" do h = { 1 => 2, 3 => 4 } h.keep_if { true }.should equal(h) end it "raises a #{frozen_error_class} if called on a frozen instance" do lambda { HashSpecs.frozen_hash.keep_if { true } }.should raise_error(frozen_error_class) lambda { HashSpecs.empty_frozen_hash.keep_if { false } }.should raise_error(frozen_error_class) end it_behaves_like :hash_iteration_no_block, :keep_if it_behaves_like :enumeratorized_with_origin_size, :keep_if, { 1 => 2, 3 => 4, 5 => 6 } end