1 files changed, 68 insertions, 0 deletions
diff --git a/spec/ruby/core/set/divide_spec.rb b/spec/ruby/core/set/divide_spec.rb
new file mode 100644
index 0000000000..409a22df75
--- /dev/null
+++ b/spec/ruby/core/set/divide_spec.rb
@@ -0,0 +1,68 @@
+require_relative '../../spec_helper'
+
+describe "Set#divide" do
+  it "divides self into a set of subsets based on the blocks return values" do
+    set = Set["one", "two", "three", "four", "five"].divide { |x| x.length }
+    set.map { |x| x.to_a.sort }.sort.should == [["five", "four"], ["one", "two"], ["three"]]
+  end
+
+  it "yields each Object to the block" do
+    ret = []
+    Set["one", "two", "three", "four", "five"].divide { |x| ret << x }
+    ret.sort.should == ["five", "four", "one", "three", "two"]
+  end
+
+  it "returns an enumerator when not passed a block" do
+    ret = Set[1, 2, 3, 4].divide
+    ret.should.is_a?(Enumerator)
+    ret.each(&:even?).should == Set[Set[1, 3], Set[2, 4]]
+  end
+end
+
+describe "Set#divide when passed a block with an arity of 2" do
+  it "divides self into a set of subsets based on the blocks return values" do
+    set = Set[1, 3, 4, 6, 9, 10, 11].divide { |x, y| (x - y).abs == 1 }
+    set.map{ |x| x.to_a.sort }.sort.should == [[1], [3, 4], [6], [9, 10, 11]]
+  end
+
+  ruby_version_is "4.0" do
+    it "yields each two Object to the block" do
+      ret = []
+      Set[1, 2].divide { |x, y| ret << [x, y] }
+      ret.sort.should == [[1, 2], [2, 1]]
+    end
+  end
+
+  ruby_version_is ""..."4.0" do
+    it "yields each two Object to the block" do
+      ret = []
+      Set[1, 2].divide { |x, y| ret << [x, y] }
+      ret.sort.should == [[1, 1], [1, 2], [2, 1], [2, 2]]
+    end
+  end
+
+  it "returns an enumerator when not passed a block" do
+    ret = Set[1, 2, 3, 4].divide
+    ret.should.is_a?(Enumerator)
+    ret.each { |a, b| (a + b).even? }.should == Set[Set[1, 3], Set[2, 4]]
+  end
+end
+
+describe "Set#divide when passed a block with an arity of > 2" do
+  it "only uses the first element if the arity > 2" do
+    set = Set["one", "two", "three", "four", "five"].divide do |x, y, z|
+      y.should == nil
+      z.should == nil
+      x.length
+    end
+    set.map { |x| x.to_a.sort }.sort.should == [["five", "four"], ["one", "two"], ["three"]]
+  end
+
+  it "only uses the first element if the arity = -1" do
+    set = Set["one", "two", "three", "four", "five"].divide do |*xs|
+      xs.size.should == 1
+      xs.first.length
+    end
+    set.map { |x| x.to_a.sort }.sort.should == [["five", "four"], ["one", "two"], ["three"]]
+  end
+end