Equalized the test load by placing an equal amount of test data in ea…

…ch process. Removed fixtures as the spec now generates the files it needs in /tmp/pspecs.

lib/parallel_specs.rb

@@ -1,42 +1,39 @@
 module ParallelSpecs
   extend self
 
-  #find all specs and partition them into groups
+  # finds all specs and partitions them into groups
   def specs_in_groups(root, num)
     specs = (Dir["#{root}/spec/**/*_spec.rb"]).sort
-
-    groups = []
-    num.times{|i| groups[i]=[]}
+    return [ specs ] if num == 1
+              
+    specs_with_sizes, total_size = find_sizes(specs)
 
-    # TODO:
-    # - test it
-    # - make it work with more than 2
+    groups = []
+    num.times { |i| groups[i] = [] }
 
+    group_size = (total_size / num.to_f)
+
+    i = 0
+    current_size = 0
+    specs_with_sizes.each do |spec|
+      current_size += spec[0]
+      i += 1 if current_size > group_size * (i+1)     
+      groups[i] << spec[1]
+    end
+
+    groups
+  end
+
+  private
+
+  def find_sizes(specs)
     total_size = 0
     specs_with_sizes = []
     specs.each do |file|
       size = File.stat(file).size
       specs_with_sizes << [ size, file ]
       total_size += size
     end
-
-    index = 0
-    current_size = 0
-    specs_with_sizes.each do |spec|
-      current_size += spec[0]
-      if index == 0 && current_size > total_size / 2
-        index += 1
-      end
-      groups[index] << spec[1]
-    end
-
-    groups
-    # 
-    # loop do
-    #   num.times do |i|
-    #     return groups if specs.empty?
-    #     groups[i] << specs.shift
-    #   end
-    # end
+    return specs_with_sizes, total_size    
   end
-end
+end

spec/parallel_specs_spec.rb

@@ -1,19 +1,53 @@
 require File.dirname(__FILE__)+'/spec_helper'
 
-FAKE_RAILS_ROOT = File.dirname(__FILE__)+'/fixtures'
+FAKE_RAILS_ROOT = '/tmp/pspecs/fixtures'
 
 describe ParallelSpecs do
+  def size_of(group)
+    group.inject(0) { |sum, spec| sum += File.stat(spec).size }
+  end
+
   describe :specs_in_groups_of do
+    before :all do
+      system "rm -rf #{FAKE_RAILS_ROOT}; mkdir -p #{FAKE_RAILS_ROOT}/spec/temp"
+
+      1.upto(100) do |i|
+        size = 100 * i
+        File.open("#{FAKE_RAILS_ROOT}/spec/temp/x#{i}_spec.rb", 'w') { |f| f.puts 'x' * size }
+      end
+    end
+
     it "finds all specs" do
-      ParallelSpecs.specs_in_groups(FAKE_RAILS_ROOT,1).should == [["./spec/fixtures/spec/a/x2_spec.rb", "./spec/fixtures/spec/a/x3_spec.rb", "./spec/fixtures/spec/x1_spec.rb", "./spec/fixtures/spec/x4_spec.rb"]]
+      ParallelSpecs.specs_in_groups(FAKE_RAILS_ROOT,1).should == 
+                                    [ Dir["#{FAKE_RAILS_ROOT}/spec/**/*_spec.rb"] ]
     end
 
-    it "partitions them into groups" do
-      ParallelSpecs.specs_in_groups(FAKE_RAILS_ROOT,2).should == [["./spec/fixtures/spec/a/x2_spec.rb", "./spec/fixtures/spec/x1_spec.rb"], ["./spec/fixtures/spec/a/x3_spec.rb", "./spec/fixtures/spec/x4_spec.rb"]]
+    it "partitions them into groups by equal size" do
+      groups = ParallelSpecs.specs_in_groups(FAKE_RAILS_ROOT, 2)
+      groups.size.should == 2
+      group0 = size_of(groups[0])
+      group1 = size_of(groups[1])
+      diff = group0 * 0.1
+      group0.should be_close(group1, diff)
+    end
+
+    it 'should partition correctly with a group size of 4' do
+      groups = ParallelSpecs.specs_in_groups(FAKE_RAILS_ROOT, 4)
+      groups.size.should == 4
+      group_size = size_of(groups[0])
+      diff = group_size * 0.1     
+      group_size.should be_close(size_of(groups[1]), diff)
+      group_size.should be_close(size_of(groups[2]), diff)
+      group_size.should be_close(size_of(groups[3]), diff)
     end
 
-    it "leaves spots empty when spec number does not match" do
-      ParallelSpecs.specs_in_groups(FAKE_RAILS_ROOT,3).should == [["./spec/fixtures/spec/a/x2_spec.rb", "./spec/fixtures/spec/x4_spec.rb"], ["./spec/fixtures/spec/a/x3_spec.rb"], ["./spec/fixtures/spec/x1_spec.rb"]]
+    it 'should partition correctly with an uneven group size' do
+      groups = ParallelSpecs.specs_in_groups(FAKE_RAILS_ROOT, 3)
+      groups.size.should == 3
+      group_size = size_of(groups[0])
+      diff = group_size * 0.1
+      group_size.should be_close(size_of(groups[1]), diff)
+      group_size.should be_close(size_of(groups[2]), diff)
     end
   end
 end