diff options
| -rw-r--r-- | lib/range_ext.rb | 6 | ||||
| -rw-r--r-- | spec/lib/range_ext_spec.rb | 28 |
2 files changed, 32 insertions, 2 deletions
diff --git a/lib/range_ext.rb b/lib/range_ext.rb index a6a3bfc5d..e7e0e903f 100644 --- a/lib/range_ext.rb +++ b/lib/range_ext.rb @@ -1,11 +1,15 @@ class Range def intersection(other) - return nil if (self.max < other.min or other.max < self.min) + return nil unless intersect?(other) [self.min, other.min].max..[self.max, other.max].min end alias_method :&, :intersection + def intersect?(other) + self.max > other.min and other.max > self.min + end + def remove(other) return self if (self.max < other.min or other.max < self.min) diff --git a/spec/lib/range_ext_spec.rb b/spec/lib/range_ext_spec.rb index cae637e47..eee488c91 100644 --- a/spec/lib/range_ext_spec.rb +++ b/spec/lib/range_ext_spec.rb @@ -1,6 +1,6 @@ require 'range_ext' RSpec.describe Range do - context "intersection" do + describe "#intersection" do it "is nil (sic) for two distinct ranges" do expect( (1..2).intersection(3..4) ).to be_nil end @@ -16,6 +16,32 @@ RSpec.describe Range do end end + describe "intersect?" do + it 'is true when the given range includes begin' do + expect( (2..4).intersect? (1..3) ).to be_truthy + end + + it 'is true when the given range includes end' do + expect( (2..4).intersect? (3..5) ).to be_truthy + end + + it 'is true when the given range includes both begin and end' do + expect( (2..4).intersect? (1..5) ).to be_truthy + end + + it 'is true when the given range is the same' do + expect( (2..4).intersect? (2..4) ).to be_truthy + end + + it 'is false when the given range is after' do + expect( (2..4).intersect? (5..7) ).to be_falsey + end + + it 'is false when the given range is before' do + expect( (2..4).intersect? (0..2) ).to be_falsey + end + end + context "remove" do it "is unchanged when the given range has no intersection" do expect( (1..2).remove(3..4) ).to eq 1..2 |