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Diffstat (limited to 'spec/ruby/core/hash/transform_keys_spec.rb')
-rw-r--r-- | spec/ruby/core/hash/transform_keys_spec.rb | 110 |
1 files changed, 110 insertions, 0 deletions
diff --git a/spec/ruby/core/hash/transform_keys_spec.rb b/spec/ruby/core/hash/transform_keys_spec.rb new file mode 100644 index 0000000000..379638bd4b --- /dev/null +++ b/spec/ruby/core/hash/transform_keys_spec.rb @@ -0,0 +1,110 @@ +require File.expand_path('../../../spec_helper', __FILE__) + +ruby_version_is "2.5" do + describe "Hash#transform_keys" do + before :each do + @hash = { a: 1, b: 2, c: 3 } + end + + it "returns new hash" do + ret = @hash.transform_keys(&:succ) + ret.should_not equal(@hash) + ret.should be_an_instance_of(Hash) + end + + it "sets the result as transformed keys with the given block" do + @hash.transform_keys(&:succ).should == { b: 1, c: 2, d: 3 } + end + + it "keeps last pair if new keys conflict" do + @hash.transform_keys { |_| :a }.should == { a: 3 } + end + + it "makes both hashes to share values" do + value = [1, 2, 3] + new_hash = { a: value }.transform_keys(&:upcase) + new_hash[:A].should equal(value) + end + + context "when no block is given" do + it "returns a sized Enumerator" do + enumerator = @hash.transform_keys + enumerator.should be_an_instance_of(Enumerator) + enumerator.size.should == @hash.size + enumerator.each(&:succ).should == { b: 1, c: 2, d: 3 } + end + end + + it "returns a Hash instance, even on subclasses" do + klass = Class.new(Hash) + h = klass.new + h[:foo] = 42 + r = h.transform_keys{|v| :"x#{v}"} + r.keys.should == [:xfoo] + r.class.should == Hash + end + end + + describe "Hash#transform_keys!" do + before :each do + @hash = { a: 1, b: 2, c: 3, d: 4 } + @initial_pairs = @hash.dup + end + + it "returns self" do + @hash.transform_keys!(&:succ).should equal(@hash) + end + + it "updates self as transformed values with the given block" do + @hash.transform_keys!(&:to_s) + @hash.should == { 'a' => 1, 'b' => 2, 'c' => 3, 'd' => 4 } + end + + it "does not prevent conflicts between new keys and old ones" do + @hash.transform_keys!(&:succ) + @hash.should == { e: 1 } + end + + it "partially modifies the contents if we broke from the block" do + @hash.transform_keys! do |v| + break if v == :c + v.succ + end + @hash.should == { c: 1, d: 4 } + end + + it "keeps later pair if new keys conflict" do + @hash.transform_keys! { |_| :a }.should == { a: 4 } + end + + context "when no block is given" do + it "returns a sized Enumerator" do + enumerator = @hash.transform_keys! + enumerator.should be_an_instance_of(Enumerator) + enumerator.size.should == @hash.size + enumerator.each(&:upcase).should == { A: 1, B: 2, C: 3, D: 4 } + end + end + + describe "on frozen instance" do + before :each do + @hash.freeze + end + + it "raises a RuntimeError on an empty hash" do + ->{ {}.freeze.transform_keys!(&:upcase) }.should raise_error(RuntimeError) + end + + it "keeps pairs and raises a RuntimeError" do + ->{ @hash.transform_keys!(&:upcase) }.should raise_error(RuntimeError) + @hash.should == @initial_pairs + end + + context "when no block is given" do + it "does not raise an exception" do + @hash.transform_keys!.should be_an_instance_of(Enumerator) + end + end + end + end +end |