1 files changed, 51 insertions, 0 deletions
diff --git a/spec/ruby/library/pathname/relative_path_from_spec.rb b/spec/ruby/library/pathname/relative_path_from_spec.rb
new file mode 100644
index 0000000000..b3bc85e307
--- /dev/null
+++ b/spec/ruby/library/pathname/relative_path_from_spec.rb
@@ -0,0 +1,51 @@
+require File.expand_path('../../../spec_helper', __FILE__)
+require 'pathname'
+
+describe "Pathname#relative_path_from" do
+  def relative_path_str(dest, base)
+    Pathname.new(dest).relative_path_from(Pathname.new(base)).to_s
+  end
+
+  it "raises an error when the two paths do not share a common prefix" do
+    lambda { relative_path_str('/usr', 'foo') }.should raise_error(ArgumentError)
+  end
+
+  it "raises an error when the base directory has .." do
+    lambda { relative_path_str('a', '..') }.should raise_error(ArgumentError)
+  end
+
+  it "retuns a path relative from root" do
+    relative_path_str('/usr', '/').should == 'usr'
+  end
+
+  it 'returns 1 level up when both paths are relative' do
+    relative_path_str('a', 'b').should == '../a'
+    relative_path_str('a', 'b/').should == '../a'
+  end
+
+  it 'returns a relative path when both are absolute' do
+    relative_path_str('/a', '/b').should == '../a'
+  end
+
+  it "returns a path relative to the current directory" do
+    relative_path_str('/usr/bin/ls', '/usr').should == 'bin/ls'
+  end
+
+  it 'returns a . when base and dest are the same' do
+    relative_path_str('/usr', '/usr').should == '.'
+  end
+
+  it 'returns the same directory with a non clean base that matches the current dir' do
+    relative_path_str('/usr', '/stuff/..').should == 'usr'
+  end
+
+  it 'returns a relative path with a non clean base that matches a different dir' do
+    relative_path_str('/usr', '/stuff/../foo').should == '../usr'
+  end
+
+  it 'returns current and pattern when only those patterns are used' do
+    relative_path_str('.', '.').should == '.'
+    relative_path_str('..', '..').should == '.'
+    relative_path_str('..', '.').should == '..'
+  end
+end