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Diffstat (limited to 'spec/ruby/core/string/comparison_spec.rb')
-rw-r--r-- | spec/ruby/core/string/comparison_spec.rb | 108 |
1 files changed, 108 insertions, 0 deletions
diff --git a/spec/ruby/core/string/comparison_spec.rb b/spec/ruby/core/string/comparison_spec.rb new file mode 100644 index 0000000000..5a0e7fabc3 --- /dev/null +++ b/spec/ruby/core/string/comparison_spec.rb @@ -0,0 +1,108 @@ +# -*- encoding: utf-8 -*- +require File.expand_path('../../../spec_helper', __FILE__) +require File.expand_path('../fixtures/classes.rb', __FILE__) + +describe "String#<=> with String" do + it "compares individual characters based on their ascii value" do + ascii_order = Array.new(256) { |x| x.chr } + sort_order = ascii_order.sort + sort_order.should == ascii_order + end + + it "returns -1 when self is less than other" do + ("this" <=> "those").should == -1 + end + + it "returns 0 when self is equal to other" do + ("yep" <=> "yep").should == 0 + end + + it "returns 1 when self is greater than other" do + ("yoddle" <=> "griddle").should == 1 + end + + it "considers string that comes lexicographically first to be less if strings have same size" do + ("aba" <=> "abc").should == -1 + ("abc" <=> "aba").should == 1 + end + + it "doesn't consider shorter string to be less if longer string starts with shorter one" do + ("abc" <=> "abcd").should == -1 + ("abcd" <=> "abc").should == 1 + end + + it "compares shorter string with corresponding number of first chars of longer string" do + ("abx" <=> "abcd").should == 1 + ("abcd" <=> "abx").should == -1 + end + + it "ignores subclass differences" do + a = "hello" + b = StringSpecs::MyString.new("hello") + + (a <=> b).should == 0 + (b <=> a).should == 0 + end + + it "returns 0 if self and other are bytewise identical and have the same encoding" do + ("ÄÖÜ" <=> "ÄÖÜ").should == 0 + end + + it "returns 0 if self and other are bytewise identical and have the same encoding" do + ("ÄÖÜ" <=> "ÄÖÜ").should == 0 + end + + it "returns -1 if self is bytewise less than other" do + ("ÄÖÛ" <=> "ÄÖÜ").should == -1 + end + + it "returns 1 if self is bytewise greater than other" do + ("ÄÖÜ" <=> "ÄÖÛ").should == 1 + end + + it "ignores encoding difference" do + ("ÄÖÛ".force_encoding("utf-8") <=> "ÄÖÜ".force_encoding("iso-8859-1")).should == -1 + ("ÄÖÜ".force_encoding("utf-8") <=> "ÄÖÛ".force_encoding("iso-8859-1")).should == 1 + end + + it "returns 0 with identical ASCII-compatible bytes of different encodings" do + ("abc".force_encoding("utf-8") <=> "abc".force_encoding("iso-8859-1")).should == 0 + end + + it "compares the indices of the encodings when the strings have identical non-ASCII-compatible bytes" do + xff_1 = [0xFF].pack('C').force_encoding("utf-8") + xff_2 = [0xFF].pack('C').force_encoding("iso-8859-1") + (xff_1 <=> xff_2).should == -1 + (xff_2 <=> xff_1).should == 1 + end +end + +# Note: This is inconsistent with Array#<=> which calls #to_ary instead of +# just using it as an indicator. +describe "String#<=>" do + it "returns nil if its argument provides neither #to_str nor #<=>" do + ("abc" <=> mock('x')).should be_nil + end + + it "uses the result of calling #to_str for comparison when #to_str is defined" do + obj = mock('x') + obj.should_receive(:to_str).and_return("aaa") + + ("abc" <=> obj).should == 1 + end + + it "uses the result of calling #<=> on its argument when #<=> is defined but #to_str is not" do + obj = mock('x') + obj.should_receive(:<=>).and_return(-1) + + ("abc" <=> obj).should == 1 + end + + it "returns nil if argument also uses an inverse comparison for <=>" do + obj = mock('x') + def obj.<=>(other); other <=> self; end + obj.should_receive(:<=>).once + + ("abc" <=> obj).should be_nil + end +end |