added tests for module candidate API

lib/pry/code.rb

@@ -68,6 +68,10 @@ class Pry
       # Attempt to extract the source code for module (or class) `mod`.
       #
       # @param [Module, Class] mod The module (or class) of interest.
+      # @param [Fixnum, nil] start_line The line number to start on, or nil to use the
+      #   method's original line numbers.
+      # @param [Fixnum] candidate_rank The module candidate (by rank)
+      #   to use (see `Pry::WrappedModule::Candidate` for more information).
       # @return [Code]
       def from_module(mod, start_line=nil, candidate_rank=0)
         candidate = Pry::WrappedModule(mod).candidate(candidate_rank)

lib/pry/module_candidate.rb

@@ -6,8 +6,7 @@ class Pry
 
     # This class represents a single candidate for a module/class definition.
     # It provides access to the source, documentation, line and file
-    # for a monkeypatch (reopening) of a class/module. All candidates
-    # are
+    # for a monkeypatch (reopening) of a class/module.
     class Candidate
       include Pry::Helpers::DocumentationHelpers
       extend Forwardable
@@ -25,6 +24,7 @@ class Pry
       def_delegators :@wrapper, *to_delegate
       private *to_delegate
 
+      # @raise [Pry::CommandError] If `rank` is out of bounds.
       # @param [Pry::WrappedModule] wrapper The associated
       #   `Pry::WrappedModule` instance that owns the candidates.
       # @param [Fixnum] rank The rank of the candidate to
@@ -35,7 +35,9 @@ class Pry
       def initialize(wrapper, rank)
         @wrapper = wrapper
 
-        if rank > (number_of_candidates - 1)
+        if number_of_candidates <= 0
+          raise CommandError, "Cannot find a definition for #{name} module!"
+        elsif rank > (number_of_candidates - 1)
           raise CommandError, "No such module candidate. Allowed candidates range is from 0 to #{number_of_candidates - 1}"
         end
 

lib/pry/wrapped_module.rb

@@ -175,7 +175,7 @@ class Pry
     # the candidate API gives you access to the module definition
     # representing each of those reopenings.
     # @raise [Pry::CommandError] If the `rank` is out of range. That
-    # is greater than `number_of_candidates - 1`.
+    #   is greater than `number_of_candidates - 1`.
     # @param [Fixnum] rank
     # @return [Pry::WrappedModule::Candidate]
     def candidate(rank)

test/candidate_helper1.rb

@@ -0,0 +1,11 @@
+# rank 0
+class CandidateTest
+  def test1
+  end
+
+  def test2
+  end
+
+  def test3
+  end
+end

test/candidate_helper2.rb

@@ -0,0 +1,8 @@
+# rank 1
+class CandidateTest
+  def test4
+  end
+
+  def test5
+  end
+end

test/test_wrapped_module.rb

@@ -8,6 +8,91 @@ describe Pry::WrappedModule do
     end
   end
 
+  describe "candidates" do
+    before do
+      class Host
+        source_files = [File.join(File.dirname(__FILE__), "candidate_helper1.rb"),
+                        File.join(File.dirname(__FILE__), "candidate_helper2.rb")]
+
+        source_files.each do |file|
+          binding.eval File.read(file), file, 1
+        end
+
+        # rank 2
+        class CandidateTest
+          def test6
+          end
+        end
+      end
+    end
+
+    describe "number_of_candidates" do
+      it 'should return the correct number of candidates' do
+        Pry::WrappedModule(Host::CandidateTest).number_of_candidates.should == 3
+      end
+    end
+
+    describe "ordering of candidates" do
+      it 'should return class with largest number of methods as primary candidate' do
+        Pry::WrappedModule(Host::CandidateTest).candidate(0).file.should =~ /helper1/
+      end
+
+      it 'should return class with second largest number of methods as second ranked candidate' do
+        Pry::WrappedModule(Host::CandidateTest).candidate(1).file.should =~ /helper2/
+      end
+
+      it 'should return class with third largest number of methods as third ranked candidate' do
+        Pry::WrappedModule(Host::CandidateTest).candidate(2).file.should =~ /#{__FILE__}/
+      end
+
+      it 'should raise when trying to access non-existent candidate' do
+        lambda { Pry::WrappedModule(Host::CandidateTest).candidate(3) }.should.raise Pry::CommandError
+      end
+    end
+
+    describe "source" do
+      it 'should return primary candidates source by default' do
+        wm = Pry::WrappedModule(Host::CandidateTest)
+        wm.source.should == wm.candidate(0).source
+      end
+
+      it 'should return source for highest ranked candidate' do
+        Pry::WrappedModule(Host::CandidateTest).candidate(0).source.should =~ /test1/
+      end
+
+      it 'should return source for second ranked candidate' do
+        Pry::WrappedModule(Host::CandidateTest).candidate(1).source.should =~ /test4/
+      end
+
+      it 'should return source for third ranked candidate' do
+        Pry::WrappedModule(Host::CandidateTest).candidate(2).source.should =~ /test6/
+      end
+    end
+
+    describe "doc" do
+      it 'should return primary candidates doc by default' do
+        wm = Pry::WrappedModule(Host::CandidateTest)
+        wm.doc.should == wm.candidate(0).doc
+      end
+
+      it 'should return doc for highest ranked candidate' do
+        Pry::WrappedModule(Host::CandidateTest).candidate(0).doc.should =~ /rank 0/
+      end
+
+      it 'should return doc for second ranked candidate' do
+        Pry::WrappedModule(Host::CandidateTest).candidate(1).doc.should =~ /rank 1/
+      end
+
+      it 'should return doc for third ranked candidate' do
+        Pry::WrappedModule(Host::CandidateTest).candidate(2).doc.should =~ /rank 2/
+      end
+    end
+
+    after do
+      Object.remove_const(:Host)
+    end
+  end
+
   describe ".method_prefix" do
     before do
       Foo = Class.new