Fix some typos

.rubocop.yml

@@ -128,7 +128,7 @@ RSpec/DescribedClass:
 RSpec/ExampleLength:
   Enabled: false
 
-# enforces using either `expect` or `allow` for stubs.  Since they do differnet things,
+# enforces using either `expect` or `allow` for stubs.  Since they do different things,
 # we should let the developer decide which to use
 RSpec/MessageExpectation:
   Enabled: false

lib/delayed/backend/active_record.rb

@@ -119,7 +119,7 @@ def self.reserve_with_scope_using_default_sql(ready_scope, worker, now)
           # This is our old fashion, tried and true, but possibly slower lookup
           # Instead of reading the entire job record for our detect loop, we select only the id,
           # and only read the full job record after we've successfully locked the job.
-          # This can have a noticable impact on large read_ahead configurations and large payload jobs.
+          # This can have a noticeable impact on large read_ahead configurations and large payload jobs.
           ready_scope.limit(worker.read_ahead).select(:id).detect do |job|
             count = ready_scope.where(id: job.id).update_all(locked_at: now, locked_by: worker.name)
             count == 1 && job.reload
@@ -184,7 +184,7 @@ def self.reserve_with_scope_using_optimized_mssql(ready_scope, worker, now)
 
         # Get the current time (GMT or local depending on DB)
         # Note: This does not ping the DB to get the time, so all your clients
-        # must have syncronized clocks.
+        # must have synchronized clocks.
         def self.db_time_now
           if Time.zone
             Time.zone.now

spec/delayed/backend/active_record_spec.rb

@@ -21,7 +21,7 @@
       end
 
       it "raises an argument error on invalid entry" do
-        expect { configuration.reserve_sql_strategy = :invald }.to raise_error(ArgumentError)
+        expect { configuration.reserve_sql_strategy = :invalid }.to raise_error(ArgumentError)
       end
     end
   end