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Diffstat (limited to 'spec/ruby/core/hash/dig_spec.rb')
-rw-r--r-- | spec/ruby/core/hash/dig_spec.rb | 68 |
1 files changed, 68 insertions, 0 deletions
diff --git a/spec/ruby/core/hash/dig_spec.rb b/spec/ruby/core/hash/dig_spec.rb new file mode 100644 index 0000000000..237c407e91 --- /dev/null +++ b/spec/ruby/core/hash/dig_spec.rb @@ -0,0 +1,68 @@ +require File.expand_path('../../../spec_helper', __FILE__) + +ruby_version_is '2.3' do + describe "Hash#dig" do + + it "returns #[] with one arg" do + h = { 0 => false, a: 1 } + h.dig(:a).should == 1 + h.dig(0).should be_false + h.dig(1).should be_nil + end + + it "returns the nested value specified by the sequence of keys" do + h = { foo: { bar: { baz: 1 } } } + h.dig(:foo, :bar, :baz).should == 1 + h.dig(:foo, :bar, :nope).should be_nil + h.dig(:foo, :baz).should be_nil + h.dig(:bar, :baz, :foo).should be_nil + end + + it "returns the nested value specified if the sequence includes an index" do + h = { foo: [1, 2, 3] } + h.dig(:foo, 2).should == 3 + end + + it "returns nil if any intermediate step is nil" do + h = { foo: { bar: { baz: 1 } } } + h.dig(:foo, :zot, :xyz).should == nil + end + + it "raises an ArgumentError if no arguments provided" do + lambda { { the: 'borg' }.dig() }.should raise_error(ArgumentError) + end + + it "handles type-mixed deep digging" do + h = {} + h[:foo] = [ { bar: [ 1 ] }, [ obj = Object.new, 'str' ] ] + def obj.dig(*args); [ 42 ] end + + h.dig(:foo, 0, :bar).should == [ 1 ] + h.dig(:foo, 0, :bar, 0).should == 1 + h.dig(:foo, 1, 1).should == 'str' + # MRI does not recurse values returned from `obj.dig` + h.dig(:foo, 1, 0, 0).should == [ 42 ] + h.dig(:foo, 1, 0, 0, 10).should == [ 42 ] + end + + it "raises TypeError if an intermediate element does not respond to #dig" do + h = {} + h[:foo] = [ { bar: [ 1 ] }, [ nil, 'str' ] ] + lambda { h.dig(:foo, 0, :bar, 0, 0) }.should raise_error(TypeError) + lambda { h.dig(:foo, 1, 1, 0) }.should raise_error(TypeError) + end + + it "calls #dig on the result of #[] with the remaining arguments" do + h = { foo: { bar: { baz: 42 } } } + h[:foo].should_receive(:dig).with(:bar, :baz).and_return(42) + h.dig(:foo, :bar, :baz).should == 42 + end + + it "respects Hash's default" do + default = {bar: 42} + h = Hash.new(default) + h.dig(:foo).should equal default + h.dig(:foo, :bar).should == 42 + end + end +end |