diff --git a/test/erb/hello.erb b/test/erb/hello.erb
new file mode 100644
index 0000000000..d5ebcb73b9
--- /dev/null
+++ b/test/erb/hello.erb
@@ -0,0 +1,4 @@
+= hello
+<% 3.times do |n| %>
+* <%= n %>
+<% end %>
diff --git a/test/erb/test_erb.rb b/test/erb/test_erb.rb
index 0572720635..b2099af6b8 100644
--- a/test/erb/test_erb.rb
+++ b/test/erb/test_erb.rb
@@ -9,7 +9,7 @@ class TestERB < Test::Unit::TestCase
     e = assert_raise(MyError) {
       erb.result
     }
-    assert_equal("(erb):1:in `raise'", e.backtrace[0])
+    assert_match(/\A\(erb\):1\b/, e.backtrace[0])
   end
 
   def test_with_filename
@@ -18,7 +18,7 @@ class TestERB < Test::Unit::TestCase
     e = assert_raise(MyError) {
       erb.result
     }
-    assert_equal("test filename:1:in `raise'", e.backtrace[0])
+    assert_match(/\Atest filename:1\b/, e.backtrace[0])
   end
 
   def test_without_filename_with_safe_level
@@ -26,7 +26,7 @@ class TestERB < Test::Unit::TestCase
     e = assert_raise(MyError) {
       erb.result
     }
-    assert_equal("(erb):1:in `raise'", e.backtrace[0])
+    assert_match(/\A\(erb\):1\b/, e.backtrace[0])
   end
 
   def test_with_filename_and_safe_level
@@ -35,6 +35,379 @@ class TestERB < Test::Unit::TestCase
     e = assert_raise(MyError) {
       erb.result
     }
-    assert_equal("test filename:1:in `raise'", e.backtrace[0])
+    assert_match(/\Atest filename:1\b/, e.backtrace[0])
+  end
+end
+
+class TestERBCore < Test::Unit::TestCase
+  def setup
+    @erb = ERB
+  end
+
+  def test_01
+    _test_01(nil)
+    _test_01(0)
+    _test_01(1)
+    _test_01(2)
+    _test_01(3)
+  end
+
+  def _test_01(safe)
+    erb = @erb.new("hello")
+    assert_equal(erb.result, "hello")
+
+    erb = @erb.new("hello", safe, 0)
+    assert_equal(erb.result, "hello")
+
+    erb = @erb.new("hello", safe, 1)
+    assert_equal(erb.result, "hello")
+
+    erb = @erb.new("hello", safe, 2)
+    assert_equal(erb.result, "hello")
+
+    src = <<EOS
+%% hi
+= hello
+<% 3.times do |n| %>
+% n=0
+* <%= n %>
+<% end %>
+EOS
+      
+    ans = <<EOS
+%% hi
+= hello
+
+% n=0
+* 0
+
+% n=0
+* 1
+
+% n=0
+* 2
+
+EOS
+    erb = @erb.new(src)
+    assert_equal(ans, erb.result)
+    erb = @erb.new(src, safe, 0)
+    assert_equal(ans, erb.result)
+    erb = @erb.new(src, safe, '')
+    assert_equal(ans, erb.result)
+
+    ans = <<EOS
+%% hi
+= hello
+% n=0
+* 0% n=0
+* 1% n=0
+* 2
+EOS
+    erb = @erb.new(src, safe, 1)
+    assert_equal(ans.chomp, erb.result)
+    erb = @erb.new(src, safe, '>')
+    assert_equal(ans.chomp, erb.result)
+
+    ans  = <<EOS
+%% hi
+= hello
+% n=0
+* 0
+% n=0
+* 1
+% n=0
+* 2
+EOS
+      
+    erb = @erb.new(src, safe, 2)
+    assert_equal(ans, erb.result)
+    erb = @erb.new(src, safe, '<>')
+    assert_equal(ans, erb.result)
+
+    ans = <<EOS
+% hi
+= hello
+
+* 0
+
+* 0
+
+* 0
+
+EOS
+    erb = @erb.new(src, safe, '%')
+    assert_equal(ans, erb.result)
+
+    ans = <<EOS
+% hi
+= hello
+* 0* 0* 0
+EOS
+    erb = @erb.new(src, safe, '%>')
+    assert_equal(ans.chomp, erb.result)
+
+    ans = <<EOS
+% hi
+= hello
+* 0
+* 0
+* 0
+EOS
+    erb = @erb.new(src, safe, '%<>')
+    assert_equal(ans, erb.result)
+  end
+
+  def test_02_safe_04
+    erb = @erb.new('<%=$SAFE%>', 4)
+    assert_equal(erb.result(TOPLEVEL_BINDING.taint), '4')
+  end
+
+  class Foo; end
+
+  def test_03_def_class
+    erb = @erb.new('hello')
+    cls = erb.def_class
+    assert_equal(Object, cls.superclass)
+    assert(cls.new.respond_to?('result'))
+    cls = erb.def_class(Foo)
+    assert_equal(Foo, cls.superclass)
+    assert(cls.new.respond_to?('result'))
+    cls = erb.def_class(Object, 'erb')
+    assert_equal(Object, cls.superclass)
+    assert(cls.new.respond_to?('erb'))
+  end
+
+  def test_04_percent
+    src = <<EOS
+%n = 1
+<%= n%>
+EOS
+    assert_equal("1\n", ERB.new(src, nil, '%').result)
+
+    src = <<EOS
+<%
+%>
+EOS
+    ans = "\n"
+    assert_equal(ans, ERB.new(src, nil, '%').result)
+
+    src = "<%\n%>"
+    # ans = "\n"
+    ans = ""
+    assert_equal(ans, ERB.new(src, nil, '%').result)
+
+    src = <<EOS
+<%
+n = 1
+%><%= n%>
+EOS
+    assert_equal("1\n", ERB.new(src, nil, '%').result)
+
+    src = <<EOS
+%n = 1
+%% <% n = 2
+n.times do |i|%>
+%% %%><%%<%= i%><%
+end%>
+EOS
+    ans = <<EOS
+% 
+% %%><%0
+% %%><%1
+EOS
+    assert_equal(ans, ERB.new(src, nil, '%').result)
+  end
+
+  class Bar; end
+
+  def test_05_def_method
+    assert(! Bar.new.respond_to?('hello'))
+    Bar.module_eval do
+      extend ERB::DefMethod
+      fname = File.join(File.dirname(File.expand_path(__FILE__)), 'hello.erb')
+      def_erb_method('hello', fname)
+    end
+    assert(Bar.new.respond_to?('hello'))
+
+    assert(! Bar.new.respond_to?('hello_world'))
+    erb = @erb.new('hello, world')
+    Bar.module_eval do
+      def_erb_method('hello_world', erb)
+    end
+    assert(Bar.new.respond_to?('hello_world'))    
+  end
+
+  def test_06_escape
+    src = <<EOS
+1.<%% : <%="<%%"%>
+2.%%> : <%="%%>"%>
+3.
+% x = "foo"
+<%=x%>
+4.
+%% print "foo"
+5.
+%% <%="foo"%>
+6.<%="
+% print 'foo'
+"%>
+7.<%="
+%% print 'foo'
+"%>
+EOS
+    ans = <<EOS
+1.<% : <%%
+2.%%> : %>
+3.
+foo
+4.
+% print "foo"
+5.
+% foo
+6.
+% print 'foo'
+
+7.
+%% print 'foo'
+
+EOS
+    assert_equal(ans, ERB.new(src, nil, '%').result)
+  end
+
+  def test_07_keep_lineno
+    src = <<EOS
+Hello, 
+% x = "World"
+<%= x%>
+% raise("lineno")
+EOS
+
+    erb = ERB.new(src, nil, '%')
+    begin
+      erb.result
+      assert(false)
+    rescue
+      assert_match(/\A\(erb\):4\b/, $@[0].to_s)
+    end
+
+    src = <<EOS
+%>
+Hello, 
+<% x = "World%%>
+"%>
+<%= x%>
+EOS
+
+    ans = <<EOS
+%>Hello, 
+World%>
+EOS
+    assert_equal(ans, ERB.new(src, nil, '>').result)
+
+    ans = <<EOS
+%>
+Hello, 
+
+World%>
+EOS
+    assert_equal(ans, ERB.new(src, nil, '<>').result)
+
+    ans = <<EOS
+%>
+Hello, 
+
+World%>
+
+EOS
+    assert_equal(ans, ERB.new(src).result)
+
+    src = <<EOS
+Hello, 
+<% x = "World%%>
+"%>
+<%= x%>
+<% raise("lineno") %>
+EOS
+
+    erb = ERB.new(src)
+    begin
+      erb.result
+      assert(false)
+    rescue
+      assert_match(/\A\(erb\):5\b/, $@[0].to_s)
+    end
+
+    erb = ERB.new(src, nil, '>')
+    begin
+      erb.result
+      assert(false)
+    rescue
+      assert_match(/\A\(erb\):5\b/, $@[0].to_s)
+    end
+
+    erb = ERB.new(src, nil, '<>')
+    begin
+      erb.result
+      assert(false)
+    rescue
+      assert_match(/\A\(erb\):5\b/, $@[0].to_s)
+    end
+
+    src = <<EOS
+% y = 'Hello'
+<%- x = "World%%>
+"-%>
+<%= x %><%- x = nil -%> 
+<% raise("lineno") %>
+EOS
+
+    erb = ERB.new(src, nil, '-')
+    begin
+      erb.result
+      assert(false)
+    rescue
+      assert_match(/\A\(erb\):5\b/, $@[0].to_s)
+    end
+
+    erb = ERB.new(src, nil, '%-')
+    begin
+      erb.result
+      assert(false)
+    rescue
+      assert_match(/\A\(erb\):5\b/, $@[0].to_s)
+    end
+  end
+
+  def test_08_explicit
+    src = <<EOS
+<% x = %w(hello world) -%>
+NotSkip <%- y = x -%> NotSkip
+<% x.each do |w| -%>
+  <%- up = w.upcase -%>
+  * <%= up %>
+<% end -%>
+ <%- z = nil -%> NotSkip <%- z = x %>
+ <%- z.each do |w| -%>
+   <%- down = w.downcase -%>
+   * <%= down %>
+   <%- up = w.upcase -%>
+   * <%= up %>
+ <%- end -%>
+KeepNewLine <%- z = nil -%> 
+EOS
+
+   ans = <<EOS
+NotSkip  NotSkip
+  * HELLO
+  * WORLD
+ NotSkip 
+   * hello
+   * HELLO
+   * world
+   * WORLD
+KeepNewLine  
+EOS
+   assert_equal(ans, ERB.new(src, nil, '-').result)
+   assert_equal(ans, ERB.new(src, nil, '-%').result)
   end
 end