Add initial tests for WeakHash.

activesupport/test/weak_hash_test.rb

@@ -0,0 +1,33 @@
+require 'abstract_unit'
+require 'active_support/weak_hash'
+
+class WeakHashTest < ActiveSupport::TestCase
+
+  def setup
+    @weak_hash = ActiveSupport::WeakHash.new
+    @str = "A";
+    @obj = Object.new
+  end
+
+  test "allows us to assign value, and return assigned value" do
+    a = @str; b = @obj
+    assert_equal @weak_hash[a] = b, b
+  end
+
+  test "should allow us to assign and read value" do
+    a = @str; b = @obj
+    assert_equal @weak_hash[a] = b, b
+    assert_equal @weak_hash[a], b
+  end
+
+  test "should use object_id to identify objects" do
+    a = Object.new
+    @weak_hash[a] = "b"
+    assert_nil @weak_hash[a.dup]
+  end
+
+  test "should find objects that have same hash" do
+    @weak_hash["a"] = "b"
+    assert_equal "b", @weak_hash["a"]
+  end
+end