feat(pipeline): add flag to disable raising exceptions

Author: philippeboyd

CHANGELOG.md

@@ -1,5 +1,7 @@
 # Unreleased
 
+- Add `exception` flag in `pipelined` allowing failed commands to be returned in the result array when set to `false`.
+
 # 5.1.0
 
 - `multi` now accept a `watch` keyword argument like `redis-client`. See #1236.

README.md

@@ -191,6 +191,28 @@ end
 # => ["OK"]
 ```
 
+### Exception management
+
+The `exception` flag in the `#pipelined` is a feature that modifies the pipeline execution behavior. When set
+to `false`, it doesn't raise an exception when a command error occurs. Instead, it allows the pipeline to execute all
+commands, and any failed command will be available in the returned array. (Defaults to `true`)
+
+```ruby
+results = redis.pipelined(exception: false) do |pipeline|
+  pipeline.set('key1', 'value1')
+  pipeline.lpush('key1', 'something') # This will fail
+  pipeline.set('key2', 'value2')
+end
+# results => ["OK", #<RedisClient::WrongTypeError: WRONGTYPE Operation against a key holding the wrong kind of value>, "OK"]
+
+results.each do |result|
+  if result.is_a?(RedisClient::CommandError)
+    # Do something with the failed result
+  end
+end
+```
+
+
 ### Executing commands atomically
 
 You can use `MULTI/EXEC` to run a number of commands in an atomic

lib/redis.rb

@@ -99,10 +99,10 @@ def _client
     @client
   end
 
-  def pipelined
+  def pipelined(exception: true)
     synchronize do |client|
-      client.pipelined do |raw_pipeline|
-        yield PipelinedConnection.new(raw_pipeline)
+      client.pipelined(exception: exception) do |raw_pipeline|
+        yield PipelinedConnection.new(raw_pipeline, exception: exception)
       end
     end
   end

lib/redis/client.rb

@@ -105,7 +105,7 @@ def blocking_call_v(timeout, command, &block)
       Client.translate_error!(error)
     end
 
-    def pipelined
+    def pipelined(exception: true)
       super
     rescue ::RedisClient::Error => error
       Client.translate_error!(error)

lib/redis/pipeline.rb

@@ -6,9 +6,10 @@ class Redis
   class PipelinedConnection
     attr_accessor :db
 
-    def initialize(pipeline, futures = [])
+    def initialize(pipeline, futures = [], exception: true)
       @pipeline = pipeline
       @futures = futures
+      @exception = exception
     end
 
     include Commands
@@ -37,7 +38,7 @@ def synchronize
     end
 
     def send_command(command, &block)
-      future = Future.new(command, block)
+      future = Future.new(command, block, @exception)
       @pipeline.call_v(command) do |result|
         future._set(result)
       end
@@ -46,7 +47,7 @@ def send_command(command, &block)
     end
 
     def send_blocking_command(command, timeout, &block)
-      future = Future.new(command, block)
+      future = Future.new(command, block, @exception)
       @pipeline.blocking_call_v(timeout, command) do |result|
         future._set(result)
       end
@@ -79,10 +80,11 @@ def initialize
   class Future < BasicObject
     FutureNotReady = ::Redis::FutureNotReady.new
 
-    def initialize(command, coerce)
+    def initialize(command, coerce, exception)
       @command = command
       @object = FutureNotReady
       @coerce = coerce
+      @exception = exception
     end
 
     def inspect
@@ -95,7 +97,7 @@ def _set(object)
     end
 
     def value
-      ::Kernel.raise(@object) if @object.is_a?(::StandardError)
+      ::Kernel.raise(@object) if @exception && @object.is_a?(::StandardError)
       @object
     end
 

redis.gemspec

@@ -45,5 +45,5 @@ Gem::Specification.new do |s|
 
   s.required_ruby_version = '>= 2.6.0'
 
-  s.add_runtime_dependency('redis-client', '>= 0.17.0')
+  s.add_runtime_dependency('redis-client', '>= 0.22.0')
 end

test/redis/pipelining_commands_test.rb

@@ -98,6 +98,18 @@ def test_assignment_of_results_inside_the_block_with_errors
     assert_raises(Redis::FutureNotReady) { @second.value }
   end
 
+  def test_assignment_of_results_inside_the_block_without_raising_exception
+    r.pipelined(exception: false) do |p|
+      @first = p.doesnt_exist
+      @second = p.sadd?("foo", 1)
+      @third = p.sadd?("foo", 1)
+    end
+
+    assert_equal RedisClient::CommandError, @first.value.class
+    assert_equal true, @second.value
+    assert_equal false, @third.value
+  end
+
   def test_assignment_of_results_inside_a_nested_block
     r.pipelined do |p|
       @first = p.sadd?("foo", 1)
@@ -111,6 +123,30 @@ def test_assignment_of_results_inside_a_nested_block
     assert_equal false, @second.value
   end
 
+  def test_nested_pipelining_returns_without_raising_exception
+    result = r.pipelined(exception: false) do |p1|
+      p1.doesnt_exist
+      p1.set("foo", "42")
+      p1.pipelined do |p2|
+        p1.doesnt_exist_again
+        p2.set("bar", "99")
+      end
+    end
+
+    assert result[0].is_a?(RedisClient::CommandError)
+    assert_equal ["doesnt_exist"], result[0].command
+
+    assert_equal "OK", result[1]
+
+    assert result[2].is_a?(RedisClient::CommandError)
+    assert_equal ["doesnt_exist_again"], result[2].command
+
+    assert_equal "OK", result[3]
+
+    assert_equal "42", r.get("foo")
+    assert_equal "99", r.get("bar")
+  end
+
   def test_futures_raise_when_confused_with_something_else
     r.pipelined do |p|
       @result = p.sadd?("foo", 1)