Raise ActiveJob::SerializationError when cannot serialize job arguments

activejob/lib/active_job/arguments.rb

 module ActiveJob
+  # Raised when an exception is raised during job arguments deserialization.
+  #
+  # Wraps the original exception raised as +original_exception+.
   class DeserializationError < StandardError
     attr_reader :original_exception
 
@@ -9,6 +12,14 @@ def initialize(e)
     end
   end
 
+  # Raised when an unsupporter argument type is being set as job argument. We
+  # currently support NilClass, Fixnum, Float, String, TrueClass, FalseClass,
+  # Bignum and object that can be represented as GlobalIDs (ex: Active Record).
+  # Also raised if you set the key for a Hash something else than a string or
+  # a symbol.
+  class SerializationError < ArgumentError
+  end
+
   module Arguments
     extend self
     TYPE_WHITELIST = [ NilClass, Fixnum, Float, String, TrueClass, FalseClass, Bignum ]
@@ -33,7 +44,7 @@ def serialize_argument(argument)
         when Hash
           Hash[ argument.map { |key, value| [ serialize_hash_key(key), serialize_argument(value) ] } ]
         else
-          raise "Unsupported argument type: #{argument.class.name}"
+          raise SerializationError.new("Unsupported argument type: #{argument.class.name}")
         end
       end
 
@@ -55,7 +66,7 @@ def serialize_hash_key(key)
         when String, Symbol
           key.to_s
         else
-          raise "Unsupported hash key type: #{key.class.name}"
+          raise SerializationError.new("Unsupported hash key type: #{key.class.name}")
         end
       end
   end

activejob/test/cases/parameters_test.rb

@@ -19,7 +19,7 @@ class ParameterSerializationTest < ActiveSupport::TestCase
     assert_equal [ [ 1 ] ], ActiveJob::Arguments.serialize([ [ 1 ] ])
     assert_equal [ 1_000_000_000_000_000_000_000 ], ActiveJob::Arguments.serialize([ 1_000_000_000_000_000_000_000 ])
 
-    err = assert_raises RuntimeError do
+    err = assert_raises ActiveJob::SerializationError do
       ActiveJob::Arguments.serialize([ 1, self ])
     end
     assert_equal "Unsupported argument type: #{self.class.name}", err.message
@@ -31,14 +31,14 @@ class ParameterSerializationTest < ActiveSupport::TestCase
   end
 
   test 'should dive deep into arrays or hashes and raise exception on complex objects' do
-    err = assert_raises RuntimeError do
+    err = assert_raises ActiveJob::SerializationError do
       ActiveJob::Arguments.serialize([ 1, [self] ])
     end
     assert_equal "Unsupported argument type: #{self.class.name}", err.message
   end
 
   test 'shoud dive deep into hashes and allow raise exception on not string/symbol keys' do
-    err = assert_raises RuntimeError do
+    err = assert_raises ActiveJob::SerializationError do
       ActiveJob::Arguments.serialize([ [ { 1 => 2 } ] ])
     end
     assert_equal "Unsupported hash key type: Fixnum", err.message