```ruby
require 'abstract_unit'

class SafeBufferTest < ActionView::TestCase
  def setup
    @buffer = ActionView::SafeBuffer.new
  end

  test "Should look like a string" do
    assert @buffer.is_a?(String)
    assert_equal "", @buffer
  end

  test "Should escape a raw string which is passed to them" do
    @buffer << "<script>"
    assert_equal "&lt;script&gt;", @buffer
  end

  test "Should NOT escape a safe value passed to it" do
    @buffer << "<script>".html_safe!
    assert_equal "<script>", @buffer
  end

  test "Should not mess with an innocuous string" do
    @buffer << "Hello"
    assert_equal "Hello", @buffer
  end

  test "Should not mess with a previously escape test" do
    @buffer << CGI.escapeHTML("<script>")
    assert_equal "&lt;script&gt;", @buffer
  end

  test "Should be considered safe" do
    assert @buffer.html_safe?
  end

  test "Should return a safe buffer when calling to_s" do
    new_buffer = @buffer.to_s
    assert_equal ActionView::SafeBuffer, new_buffer.class
  end
end
```

Fix failing safe buffer test. We don't patch CGI.escapeHTML, only ERB:Util.
user
```ruby
require 'abstract_unit'

class SafeBufferTest < ActionView::TestCase
  def setup
    @buffer = ActionView::SafeBuffer.new
  end

  test "Should look like a string" do
    assert @buffer.is_a?(String)
    assert_equal "", @buffer
  end

  test "Should escape a raw string which is passed to them" do
    @buffer << "<script>"
    assert_equal "&lt;script&gt;", @buffer
  end

  test "Should NOT escape a safe value passed to it" do
    @buffer << "<script>".html_safe!
    assert_equal "<script>", @buffer
  end

  test "Should not mess with an innocuous string" do
    @buffer << "Hello"
    assert_equal "Hello", @buffer
  end

  test "Should not mess with a previously escape test" do
    @buffer << ERB::Util.html_escape("<script>")
    assert_equal "&lt;script&gt;", @buffer
  end

  test "Should be considered safe" do
    assert @buffer.html_safe?
  end

  test "Should return a safe buffer when calling to_s" do
    new_buffer = @buffer.to_s
    assert_equal ActionView::SafeBuffer, new_buffer.class
  end
end
```
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