Add CachingTools::HashCaching to simplify the creation of nested, autofilling hashes.

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@4059 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

1 files changed, 81 insertions, 0 deletions

diff --git a/activesupport/test/caching_tools_test.rb b/activesupport/test/caching_tools_test.rb
new file mode 100644
index 0000000000..9f3e42e496
--- /dev/null
+++ b/activesupport/test/caching_tools_test.rb
@@ -0,0 +1,81 @@
+require 'test/unit'
+require File.dirname(__FILE__)+'/../lib/active_support/caching_tools'
+
+class HashCachingTests < Test::Unit::TestCase
+  
+  def cached(&proc)
+    return @cached if @cached
+    
+    @cached_class = Class.new(&proc)
+    @cached_class.class_eval do
+      extend ActiveSupport::CachingTools::HashCaching
+      hash_cache :slow_method
+    end
+    @cached = @cached_class.new
+  end
+  
+  def test_cache_access_should_call_method
+    cached do
+      def slow_method(a) raise "I should be here: #{a}"; end
+    end
+    assert_raises(RuntimeError) { cached.slow_method_cache[1] }
+  end
+  
+  def test_cache_access_should_actually_cache
+    cached do
+      def slow_method(a)
+        (@x ||= [])
+        if @x.include?(a) then raise "Called twice for #{a}!"
+        else
+          @x << a
+          a + 1
+        end
+      end
+    end
+    assert_equal 11, cached.slow_method_cache[10]
+    assert_equal 12, cached.slow_method_cache[11]
+    assert_equal 11, cached.slow_method_cache[10]
+    assert_equal 12, cached.slow_method_cache[11]
+  end
+  
+  def test_cache_should_be_clearable
+    cached do
+      def slow_method(a)
+        @x ||= 0
+        @x += 1
+      end
+    end
+    assert_equal 1, cached.slow_method_cache[:a]
+    assert_equal 2, cached.slow_method_cache[:b]
+    assert_equal 3, cached.slow_method_cache[:c]
+    
+    assert_equal 1, cached.slow_method_cache[:a]
+    assert_equal 2, cached.slow_method_cache[:b]
+    assert_equal 3, cached.slow_method_cache[:c]
+    
+    cached.slow_method_cache.clear
+    
+    assert_equal 4, cached.slow_method_cache[:a]
+    assert_equal 5, cached.slow_method_cache[:b]
+    assert_equal 6, cached.slow_method_cache[:c]
+  end
+  
+  def test_deep_caches_should_work_too
+    cached do
+      def slow_method(a, b, c)
+        a + b + c
+      end
+    end
+    assert_equal 3, cached.slow_method_cache[1][1][1]
+    assert_equal 7, cached.slow_method_cache[1][2][4]
+    assert_equal 7, cached.slow_method_cache[1][2][4]
+    assert_equal 7, cached.slow_method_cache[4][2][1]
+    
+    assert_equal({
+      1 => {1 => {1 => 3}, 2 => {4 => 7}},
+      4 => {2 => {1 => 7}}},
+      cached.slow_method_cache
+    )
+  end
+  
+end