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Diffstat (limited to 'spec/ruby/core/hash/assoc_spec.rb')
-rw-r--r-- | spec/ruby/core/hash/assoc_spec.rb | 50 |
1 files changed, 50 insertions, 0 deletions
diff --git a/spec/ruby/core/hash/assoc_spec.rb b/spec/ruby/core/hash/assoc_spec.rb new file mode 100644 index 0000000000..0b10720b6f --- /dev/null +++ b/spec/ruby/core/hash/assoc_spec.rb @@ -0,0 +1,50 @@ +require File.expand_path('../../../spec_helper', __FILE__) + +describe "Hash#assoc" do + before :each do + @h = {apple: :green, orange: :orange, grape: :green, banana: :yellow} + end + + it "returns an Array if the argument is == to a key of the Hash" do + @h.assoc(:apple).should be_an_instance_of(Array) + end + + it "returns a 2-element Array if the argument is == to a key of the Hash" do + @h.assoc(:grape).size.should == 2 + end + + it "sets the first element of the Array to the located key" do + @h.assoc(:banana).first.should == :banana + end + + it "sets the last element of the Array to the value of the located key" do + @h.assoc(:banana).last.should == :yellow + end + + it "only returns the first matching key-value pair for identity hashes" do + # Avoid literal String keys in Hash#[]= due to https://bugs.ruby-lang.org/issues/12855 + h = {}.compare_by_identity + k1 = 'pear' + h[k1] = :red + k2 = 'pear' + h[k2] = :green + h.size.should == 2 + h.keys.grep(/pear/).size.should == 2 + h.assoc('pear').should == ['pear', :red] + end + + it "uses #== to compare the argument to the keys" do + @h[1.0] = :value + 1.should == 1.0 + @h.assoc(1).should == [1.0, :value] + end + + it "returns nil if the argument is not a key of the Hash" do + @h.assoc(:green).should be_nil + end + + it "returns nil if the argument is not a key of the Hash even when there is a default" do + Hash.new(42).merge!( foo: :bar ).assoc(42).should be_nil + Hash.new{|h, k| h[k] = 42}.merge!( foo: :bar ).assoc(42).should be_nil + end +end |