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Diffstat (limited to 'spec/ruby/core/array/minus_spec.rb')
-rw-r--r-- | spec/ruby/core/array/minus_spec.rb | 87 |
1 files changed, 87 insertions, 0 deletions
diff --git a/spec/ruby/core/array/minus_spec.rb b/spec/ruby/core/array/minus_spec.rb new file mode 100644 index 0000000000..5ef90385eb --- /dev/null +++ b/spec/ruby/core/array/minus_spec.rb @@ -0,0 +1,87 @@ +require File.expand_path('../../../spec_helper', __FILE__) +require File.expand_path('../fixtures/classes', __FILE__) + +describe "Array#-" do + it "creates an array minus any items from other array" do + ([] - [ 1, 2, 4 ]).should == [] + ([1, 2, 4] - []).should == [1, 2, 4] + ([ 1, 2, 3, 4, 5 ] - [ 1, 2, 4 ]).should == [3, 5] + end + + it "removes multiple items on the lhs equal to one on the rhs" do + ([1, 1, 2, 2, 3, 3, 4, 5] - [1, 2, 4]).should == [3, 3, 5] + end + + it "properly handles recursive arrays" do + empty = ArraySpecs.empty_recursive_array + (empty - empty).should == [] + + ([] - ArraySpecs.recursive_array).should == [] + + array = ArraySpecs.recursive_array + (array - array).should == [] + end + + it "tries to convert the passed arguments to Arrays using #to_ary" do + obj = mock('[2,3,3,4]') + obj.should_receive(:to_ary).and_return([2, 3, 3, 4]) + ([1, 1, 2, 2, 3, 4] - obj).should == [1, 1] + end + + it "raises a TypeError if the argument cannot be coerced to an Array by calling #to_ary" do + obj = mock('not an array') + lambda { [1, 2, 3] - obj }.should raise_error(TypeError) + end + + it "does not return subclass instance for Array subclasses" do + (ArraySpecs::MyArray[1, 2, 3] - []).should be_an_instance_of(Array) + (ArraySpecs::MyArray[1, 2, 3] - ArraySpecs::MyArray[]).should be_an_instance_of(Array) + ([1, 2, 3] - ArraySpecs::MyArray[]).should be_an_instance_of(Array) + end + + it "does not call to_ary on array subclasses" do + ([5, 6, 7] - ArraySpecs::ToAryArray[7]).should == [5, 6] + end + + it "removes an item identified as equivalent via #hash and #eql?" do + obj1 = mock('1') + obj2 = mock('2') + obj1.should_receive(:hash).at_least(1).and_return(0) + obj2.should_receive(:hash).at_least(1).and_return(0) + obj1.should_receive(:eql?).at_least(1).and_return(true) + + ([obj1] - [obj2]).should == [] + ([obj1, obj1, obj2, obj2] - [obj2]).should == [] + end + + it "doesn't remove an item with the same hash but not #eql?" do + obj1 = mock('1') + obj2 = mock('2') + obj1.should_receive(:hash).at_least(1).and_return(0) + obj2.should_receive(:hash).at_least(1).and_return(0) + obj1.should_receive(:eql?).at_least(1).and_return(false) + + ([obj1] - [obj2]).should == [obj1] + ([obj1, obj1, obj2, obj2] - [obj2]).should == [obj1, obj1] + end + + it "removes an identical item even when its #eql? isn't reflexive" do + x = mock('x') + x.should_receive(:hash).at_least(1).and_return(42) + x.stub!(:eql?).and_return(false) # Stubbed for clarity and latitude in implementation; not actually sent by MRI. + + ([x] - [x]).should == [] + end + + it "is not destructive" do + a = [1, 2, 3] + a - [] + a.should == [1, 2, 3] + a - [1] + a.should == [1, 2, 3] + a - [1,2,3] + a.should == [1, 2, 3] + a - [:a, :b, :c] + a.should == [1, 2, 3] + end +end |