init commit

activesupport/lib/active_support/cache/redis_cache_store.rb

@@ -140,11 +140,12 @@ def build_redis_client(url:, **redis_options)
       # Race condition TTL is not set by default. This can be used to avoid
       # "thundering herd" cache writes when hot cache entries are expired.
       # See <tt>ActiveSupport::Cache::Store#fetch</tt> for more.
-      def initialize(namespace: nil, compress: true, compress_threshold: 1.kilobyte, coder: default_coder, expires_in: nil, race_condition_ttl: nil, error_handler: DEFAULT_ERROR_HANDLER, **redis_options)
+      def initialize(namespace: nil, compress: true, compress_threshold: 1.kilobyte, coder: default_coder, expires_in: nil, race_condition_ttl: nil, error_handler: DEFAULT_ERROR_HANDLER, raise_errors: false, **redis_options)
         @redis_options = redis_options
 
         @max_key_bytesize = MAX_KEY_BYTESIZE
         @error_handler = error_handler
+        @raise_errors = raise_errors
 
         super namespace: namespace,
           compress: compress, compress_threshold: compress_threshold,
@@ -460,7 +461,12 @@ def failsafe(method, returning: nil)
           yield
         rescue ::Redis::BaseError => e
           handle_exception exception: e, method: method, returning: returning
-          returning
+
+          if @raise_errors
+            raise e
+          else
+            returning
+          end
         end
 
         def handle_exception(exception:, method:, returning:)

activesupport/test/cache/behaviors.rb

@@ -9,4 +9,5 @@
 require_relative "behaviors/connection_pool_behavior"
 require_relative "behaviors/encoded_key_cache_behavior"
 require_relative "behaviors/failure_safety_behavior"
+require_relative "behaviors/failure_raising_behavior"
 require_relative "behaviors/local_cache_behavior"

activesupport/test/cache/behaviors/failure_raising_behavior.rb

@@ -0,0 +1,93 @@
+# frozen_string_literal: true
+
+module FailureRaisingBehavior
+  def test_fetch_read_failure_raises
+    @cache.write("foo", "bar")
+
+    emulating_unavailability do |cache|
+      cache.fetch("foo")
+    end
+  end
+
+  def test_fetch_with_block_read_failure_raises
+    @cache.write("foo", "bar")
+
+    emulating_unavailability do |cache|
+      cache.fetch("foo") { '1' }
+    end
+  end
+
+  def test_read_failure_raises
+    @cache.write("foo", "bar")
+
+    emulating_unavailability do |cache|
+      cache.read("foo")
+    end
+  end
+
+  def test_read_multi_failure_raises
+    @cache.write_multi("foo" => "bar", "baz" => "quux")
+
+    emulating_unavailability do |cache|
+      cache.read_multi("foo", "baz")
+    end
+  end
+
+  def test_write_failure_raises
+    emulating_unavailability do |cache|
+      cache.write("foo", "bar")
+    end
+  end
+
+  def test_write_multi_failure_raises
+    emulating_unavailability do |cache|
+      cache.write_multi("foo" => "bar", "baz" => "quux")
+    end
+  end
+
+  def test_fetch_multi_failure_raises
+    @cache.write_multi("foo" => "bar", "baz" => "quux")
+
+    emulating_unavailability do |cache|
+       cache.fetch_multi("foo", "baz") { |k| "unavailable" }
+    end
+  end
+
+  def test_delete_failure_raises
+    @cache.write("foo", "bar")
+
+    emulating_unavailability do |cache|
+      cache.delete("foo")
+    end
+  end
+
+  def test_exist_failure_raises
+    @cache.write("foo", "bar")
+
+    emulating_unavailability do |cache|
+      cache.exist?("foo")
+    end
+  end
+
+  def test_increment_failure_raises
+    @cache.write("foo", 1, raw: true)
+
+    emulating_unavailability do |cache|
+      cache.increment("foo")
+    end
+  end
+
+  def test_decrement_failure_raises
+    @cache.write("foo", 1, raw: true)
+
+    emulating_unavailability do |cache|
+      cache.decrement("foo")
+    end
+  end
+
+  def test_clear_failure_returns_nil
+    emulating_unavailability do |cache|
+      assert_nil cache.clear
+    end
+  end
+end

activesupport/test/cache/behaviors/failure_safety_behavior.rb

@@ -9,7 +9,17 @@ def test_fetch_read_failure_returns_nil
     end
   end
 
-  def test_fetch_read_failure_does_not_attempt_to_write
+  ##
+  # Though the `write` part of fetch fails for the same reason
+  # `read` will, the block result is still executed and returned.
+  def test_fetch_read_failure_returns_block_result
+    @cache.write("foo", "bar")
+
+    emulating_unavailability do |cache|
+      val = cache.fetch("foo") { '1' }
+
+      assert_equal '1', val
+    end
   end
 
   def test_read_failure_returns_nil

activesupport/test/cache/stores/redis_cache_store_test.rb

@@ -283,6 +283,40 @@ def ensure_connected
     end
   end
 
+  class FailureRaisingFromUnavailableClientTest < StoreTest
+    include FailureRaisingBehavior
+
+    private
+    def emulating_unavailability
+      old_client = Redis.send(:remove_const, :Client)
+      Redis.const_set(:Client, UnavailableRedisClient)
+
+      assert_raise Redis::BaseConnectionError do
+        yield ActiveSupport::Cache::RedisCacheStore.new(namespace: @namespace, raise_errors: true)
+      end
+    ensure
+      Redis.send(:remove_const, :Client)
+      Redis.const_set(:Client, old_client)
+    end
+  end
+
+  class FailureRaisingFromMaxClientsReachedErrorTest < StoreTest
+    include FailureRaisingBehavior
+
+    private
+    def emulating_unavailability
+      old_client = Redis.send(:remove_const, :Client)
+      Redis.const_set(:Client, MaxClientsReachedRedisClient)
+
+      assert_raise Redis::CommandError do
+        yield ActiveSupport::Cache::RedisCacheStore.new(namespace: @namespace, raise_errors: true)
+      end
+    ensure
+      Redis.send(:remove_const, :Client)
+      Redis.const_set(:Client, old_client)
+    end
+  end
+
   class FailureSafetyFromUnavailableClientTest < StoreTest
     include FailureSafetyBehavior