Fix `ActiveSupport::Cache` compression

(See previous commit for a description of the issue)

1 files changed, 21 insertions, 2 deletions

diff --git a/activesupport/test/cache/behaviors/cache_store_behavior.rb b/activesupport/test/cache/behaviors/cache_store_behavior.rb
index 84a3648ad0..0806665c27 100644
--- a/activesupport/test/cache/behaviors/cache_store_behavior.rb
+++ b/activesupport/test/cache/behaviors/cache_store_behavior.rb
@@ -162,7 +162,7 @@ module CacheStoreBehavior
   end
 
   def test_nil_with_compress_low_compress_threshold
-    assert_uncompressed(nil, compress: true, compress_threshold: 2)
+    assert_uncompressed(nil, compress: true, compress_threshold: 1)
   end
 
   def test_small_string_with_default_compression_settings
@@ -178,7 +178,7 @@ module CacheStoreBehavior
   end
 
   def test_small_string_with_low_compress_threshold
-    assert_compressed(SMALL_STRING, compress: true, compress_threshold: 2)
+    assert_compressed(SMALL_STRING, compress: true, compress_threshold: 1)
   end
 
   def test_small_object_with_default_compression_settings
@@ -229,6 +229,25 @@ module CacheStoreBehavior
     assert_uncompressed(LARGE_OBJECT, compress: true, compress_threshold: 1.megabyte)
   end
 
+  def test_incompressable_data
+    assert_uncompressed(nil, compress: true, compress_threshold: 1)
+    assert_uncompressed(true, compress: true, compress_threshold: 1)
+    assert_uncompressed(false, compress: true, compress_threshold: 1)
+    assert_uncompressed(0, compress: true, compress_threshold: 1)
+    assert_uncompressed(1.2345, compress: true, compress_threshold: 1)
+    assert_uncompressed("", compress: true, compress_threshold: 1)
+
+    incompressible = nil
+
+    # generate an incompressible string
+    loop do
+      incompressible = SecureRandom.bytes(1.kilobyte)
+      break if incompressible.bytesize < Zlib::Deflate.deflate(incompressible).bytesize
+    end
+
+    assert_uncompressed(incompressible, compress: true, compress_threshold: 1)
+  end
+
   def test_cache_key
     obj = Object.new
     def obj.cache_key