Added BaseWorker class (#1887)

* Added BaseWorker class

* Moved logging related functions to logutils

* Remove uneeded colorize function

* Updated worker.get_current_job_id() to not fail when job ID is None

* job.restore() shouldn't crash if  is not present

* Fix various as_text() related crashes

rq/cli/cli.py

@@ -31,13 +31,12 @@ from rq.defaults import (
     DEFAULT_MAINTENANCE_TASK_INTERVAL,
 )
 from rq.exceptions import InvalidJobOperationError
+from rq.job import JobStatus
+from rq.logutils import blue
 from rq.registry import FailedJobRegistry, clean_registries
-from rq.utils import import_attribute, get_call_string, make_colorizer
 from rq.suspension import suspend as connection_suspend, resume as connection_resume, is_suspended
+from rq.utils import import_attribute, get_call_string
 from rq.worker_registration import clean_worker_registry
-from rq.job import JobStatus
-
-blue = make_colorizer('darkblue')
 
 
 @click.group()

rq/job.py

@@ -158,7 +158,7 @@ class Job:
         serializer=None,
         *,
         on_success: Optional[Union['Callback', Callable[..., Any]]] = None,
-        on_failure: Optional[Union['Callback', Callable[..., Any]]] = None
+        on_failure: Optional[Union['Callback', Callable[..., Any]]] = None,
     ) -> 'Job':
         """Creates a new Job instance for the given function, arguments, and
         keyword arguments.
@@ -239,16 +239,18 @@ class Job:
 
         if on_success:
             if not isinstance(on_success, Callback):
-                warnings.warn('Passing a `Callable` `on_success` is deprecated, pass `Callback` instead',
-                              DeprecationWarning)
+                warnings.warn(
+                    'Passing a `Callable` `on_success` is deprecated, pass `Callback` instead', DeprecationWarning
+                )
                 on_success = Callback(on_success)  # backward compatibility
             job._success_callback_name = on_success.name
             job._success_callback_timeout = on_success.timeout
 
         if on_failure:
             if not isinstance(on_failure, Callback):
-                warnings.warn('Passing a `Callable` `on_failure` is deprecated, pass `Callback` instead',
-                              DeprecationWarning)
+                warnings.warn(
+                    'Passing a `Callable` `on_failure` is deprecated, pass `Callback` instead', DeprecationWarning
+                )
                 on_failure = Callback(on_failure)  # backward compatibility
             job._failure_callback_name = on_failure.name
             job._failure_callback_timeout = on_failure.timeout
@@ -302,7 +304,8 @@ class Job:
             status (JobStatus): The Job Status
         """
         if refresh:
-            self._status = as_text(self.connection.hget(self.key, 'status'))
+            status = self.connection.hget(self.key, 'status')
+            self._status = as_text(status) if status else None
         return self._status
 
     def set_status(self, status: JobStatus, pipeline: Optional['Pipeline'] = None) -> None:
@@ -872,9 +875,9 @@ class Job:
             self.data = raw_data
 
         self.created_at = str_to_date(obj.get('created_at'))
-        self.origin = as_text(obj.get('origin'))
+        self.origin = as_text(obj.get('origin')) if obj.get('origin') else None
         self.worker_name = obj.get('worker_name').decode() if obj.get('worker_name') else None
-        self.description = as_text(obj.get('description'))
+        self.description = as_text(obj.get('description')) if obj.get('description') else None
         self.enqueued_at = str_to_date(obj.get('enqueued_at'))
         self.started_at = str_to_date(obj.get('started_at'))
         self.ended_at = str_to_date(obj.get('ended_at'))
@@ -1360,8 +1363,7 @@ class Job:
             self.success_callback(self, self.connection, result)
 
     def execute_failure_callback(self, death_penalty_class: Type[BaseDeathPenalty], *exc_info):
-        """Executes failure_callback with possible timeout
-        """
+        """Executes failure_callback with possible timeout"""
         if not self.failure_callback:
             return
 
@@ -1369,7 +1371,7 @@ class Job:
         try:
             with death_penalty_class(self.failure_callback_timeout, JobTimeoutException, job_id=self.id):
                 self.failure_callback(self, self.connection, *exc_info)
-        except Exception: # noqa
+        except Exception:  # noqa
             logger.exception(f'Job {self.id}: error while executing failure callback')
             raise
 

rq/logutils.py

@@ -2,10 +2,109 @@ import logging
 import sys
 from typing import Union
 
-from rq.utils import ColorizingStreamHandler
 from rq.defaults import DEFAULT_LOGGING_FORMAT, DEFAULT_LOGGING_DATE_FORMAT
 
 
+class _Colorizer:
+    def __init__(self):
+        esc = "\x1b["
+
+        self.codes = {}
+        self.codes[""] = ""
+        self.codes["reset"] = esc + "39;49;00m"
+
+        self.codes["bold"] = esc + "01m"
+        self.codes["faint"] = esc + "02m"
+        self.codes["standout"] = esc + "03m"
+        self.codes["underline"] = esc + "04m"
+        self.codes["blink"] = esc + "05m"
+        self.codes["overline"] = esc + "06m"
+
+        dark_colors = ["black", "darkred", "darkgreen", "brown", "darkblue", "purple", "teal", "lightgray"]
+        light_colors = ["darkgray", "red", "green", "yellow", "blue", "fuchsia", "turquoise", "white"]
+
+        x = 30
+        for d, l in zip(dark_colors, light_colors):
+            self.codes[d] = esc + "%im" % x
+            self.codes[l] = esc + "%i;01m" % x
+            x += 1
+
+        del d, l, x
+
+        self.codes["darkteal"] = self.codes["turquoise"]
+        self.codes["darkyellow"] = self.codes["brown"]
+        self.codes["fuscia"] = self.codes["fuchsia"]
+        self.codes["white"] = self.codes["bold"]
+
+        if hasattr(sys.stdout, "isatty"):
+            self.notty = not sys.stdout.isatty()
+        else:
+            self.notty = True
+
+    def colorize(self, color_key, text):
+        if self.notty:
+            return text
+        else:
+            return self.codes[color_key] + text + self.codes["reset"]
+
+
+colorizer = _Colorizer()
+
+
+def make_colorizer(color: str):
+    """Creates a function that colorizes text with the given color.
+
+    For example::
+
+        ..codeblock::python
+
+            >>> green = make_colorizer('darkgreen')
+            >>> red = make_colorizer('red')
+            >>>
+            >>> # You can then use:
+            >>> print("It's either " + green('OK') + ' or ' + red('Oops'))
+    """
+
+    def inner(text):
+        return colorizer.colorize(color, text)
+
+    return inner
+
+
+green = make_colorizer('darkgreen')
+yellow = make_colorizer('darkyellow')
+blue = make_colorizer('darkblue')
+red = make_colorizer('darkred')
+
+
+class ColorizingStreamHandler(logging.StreamHandler):
+    levels = {
+        logging.WARNING: yellow,
+        logging.ERROR: red,
+        logging.CRITICAL: red,
+    }
+
+    def __init__(self, exclude=None, *args, **kwargs):
+        self.exclude = exclude
+        super().__init__(*args, **kwargs)
+
+    @property
+    def is_tty(self):
+        isatty = getattr(self.stream, 'isatty', None)
+        return isatty and isatty()
+
+    def format(self, record):
+        message = logging.StreamHandler.format(self, record)
+        if self.is_tty:
+            # Don't colorize any traceback
+            parts = message.split('\n', 1)
+            parts[0] = " ".join([parts[0].split(" ", 1)[0], parts[0].split(" ", 1)[1]])
+
+            message = '\n'.join(parts)
+
+        return message
+
+
 def setup_loghandlers(
     level: Union[int, str, None] = None,
     date_format: str = DEFAULT_LOGGING_DATE_FORMAT,

rq/queue.py

@@ -22,13 +22,11 @@ from .connections import resolve_connection
 from .defaults import DEFAULT_RESULT_TTL
 from .exceptions import DequeueTimeout, NoSuchJobError
 from .job import Job, JobStatus
+from .logutils import blue, green, yellow
 from .types import FunctionReferenceType, JobDependencyType
 from .serializers import resolve_serializer
-from .utils import backend_class, get_version, import_attribute, make_colorizer, parse_timeout, utcnow, compact
+from .utils import backend_class, get_version, import_attribute, parse_timeout, utcnow, compact
 
-green = make_colorizer('darkgreen')
-yellow = make_colorizer('darkyellow')
-blue = make_colorizer('darkblue')
 
 logger = logging.getLogger("rq.queue")
 
@@ -71,8 +69,11 @@ class Queue:
 
     @classmethod
     def all(
-            cls, connection: Optional['Redis'] = None, job_class: Optional[Type['Job']] = None,
-            serializer=None, death_penalty_class: Optional[Type[BaseDeathPenalty]] = None
+        cls,
+        connection: Optional['Redis'] = None,
+        job_class: Optional[Type['Job']] = None,
+        serializer=None,
+        death_penalty_class: Optional[Type[BaseDeathPenalty]] = None,
     ) -> List['Queue']:
         """Returns an iterable of all Queues.
 
@@ -89,8 +90,11 @@ class Queue:
 
         def to_queue(queue_key):
             return cls.from_queue_key(
-                as_text(queue_key), connection=connection, job_class=job_class,
-                serializer=serializer, death_penalty_class=death_penalty_class
+                as_text(queue_key),
+                connection=connection,
+                job_class=job_class,
+                serializer=serializer,
+                death_penalty_class=death_penalty_class,
             )
 
         all_registerd_queues = connection.smembers(cls.redis_queues_keys)
@@ -99,12 +103,12 @@ class Queue:
 
     @classmethod
     def from_queue_key(
-            cls,
-            queue_key: str,
-            connection: Optional['Redis'] = None,
-            job_class: Optional[Type['Job']] = None,
-            serializer: Any = None,
-            death_penalty_class: Optional[Type[BaseDeathPenalty]] = None,
+        cls,
+        queue_key: str,
+        connection: Optional['Redis'] = None,
+        job_class: Optional[Type['Job']] = None,
+        serializer: Any = None,
+        death_penalty_class: Optional[Type[BaseDeathPenalty]] = None,
     ) -> 'Queue':
         """Returns a Queue instance, based on the naming conventions for naming
         the internal Redis keys.  Can be used to reverse-lookup Queues by their
@@ -126,20 +130,25 @@ class Queue:
         prefix = cls.redis_queue_namespace_prefix
         if not queue_key.startswith(prefix):
             raise ValueError('Not a valid RQ queue key: {0}'.format(queue_key))
-        name = queue_key[len(prefix):]
-        return cls(name, connection=connection, job_class=job_class, serializer=serializer,
-                   death_penalty_class=death_penalty_class)
+        name = queue_key[len(prefix) :]
+        return cls(
+            name,
+            connection=connection,
+            job_class=job_class,
+            serializer=serializer,
+            death_penalty_class=death_penalty_class,
+        )
 
     def __init__(
-            self,
-            name: str = 'default',
-            default_timeout: Optional[int] = None,
-            connection: Optional['Redis'] = None,
-            is_async: bool = True,
-            job_class: Union[str, Type['Job'], None] = None,
-            serializer: Any = None,
-            death_penalty_class: Type[BaseDeathPenalty] = UnixSignalDeathPenalty,
-            **kwargs,
+        self,
+        name: str = 'default',
+        default_timeout: Optional[int] = None,
+        connection: Optional['Redis'] = None,
+        is_async: bool = True,
+        job_class: Union[str, Type['Job'], None] = None,
+        serializer: Any = None,
+        death_penalty_class: Type[BaseDeathPenalty] = UnixSignalDeathPenalty,
+        **kwargs,
     ):
         """Initializes a Queue object.
 
@@ -207,6 +216,7 @@ class Queue:
     @property
     def scheduler_pid(self) -> int:
         from rq.scheduler import RQScheduler
+
         pid = self.connection.get(RQScheduler.get_locking_key(self.name))
         return int(pid.decode()) if pid is not None else None
 
@@ -444,10 +454,10 @@ class Queue:
 
         self.connection.rename(self.key, COMPACT_QUEUE)
         while True:
-            job_id = as_text(self.connection.lpop(COMPACT_QUEUE))
+            job_id = self.connection.lpop(COMPACT_QUEUE)
             if job_id is None:
                 break
-            if self.job_class.exists(job_id, self.connection):
+            if self.job_class.exists(as_text(job_id), self.connection):
                 self.connection.rpush(self.key, job_id)
 
     def push_job_id(self, job_id: str, pipeline: Optional['Pipeline'] = None, at_front: bool = False):
@@ -469,23 +479,23 @@ class Queue:
             self.log.debug('Pushed job %s into %s', blue(job_id), green(self.name))
 
     def create_job(
-            self,
-            func: 'FunctionReferenceType',
-            args: Union[Tuple, List, None] = None,
-            kwargs: Optional[Dict] = None,
-            timeout: Optional[int] = None,
-            result_ttl: Optional[int] = None,
-            ttl: Optional[int] = None,
-            failure_ttl: Optional[int] = None,
-            description: Optional[str] = None,
-            depends_on: Optional['JobDependencyType'] = None,
-            job_id: Optional[str] = None,
-            meta: Optional[Dict] = None,
-            status: JobStatus = JobStatus.QUEUED,
-            retry: Optional['Retry'] = None,
-            *,
-            on_success: Optional[Callable] = None,
-            on_failure: Optional[Callable] = None,
+        self,
+        func: 'FunctionReferenceType',
+        args: Union[Tuple, List, None] = None,
+        kwargs: Optional[Dict] = None,
+        timeout: Optional[int] = None,
+        result_ttl: Optional[int] = None,
+        ttl: Optional[int] = None,
+        failure_ttl: Optional[int] = None,
+        description: Optional[str] = None,
+        depends_on: Optional['JobDependencyType'] = None,
+        job_id: Optional[str] = None,
+        meta: Optional[Dict] = None,
+        status: JobStatus = JobStatus.QUEUED,
+        retry: Optional['Retry'] = None,
+        *,
+        on_success: Optional[Callable] = None,
+        on_failure: Optional[Callable] = None,
     ) -> Job:
         """Creates a job based on parameters given
 
@@ -611,23 +621,23 @@ class Queue:
         return job
 
     def enqueue_call(
-            self,
-            func: 'FunctionReferenceType',
-            args: Union[Tuple, List, None] = None,
-            kwargs: Optional[Dict] = None,
-            timeout: Optional[int] = None,
-            result_ttl: Optional[int] = None,
-            ttl: Optional[int] = None,
-            failure_ttl: Optional[int] = None,
-            description: Optional[str] = None,
-            depends_on: Optional['JobDependencyType'] = None,
-            job_id: Optional[str] = None,
-            at_front: bool = False,
-            meta: Optional[Dict] = None,
-            retry: Optional['Retry'] = None,
-            on_success: Optional[Callable[..., Any]] = None,
-            on_failure: Optional[Callable[..., Any]] = None,
-            pipeline: Optional['Pipeline'] = None,
+        self,
+        func: 'FunctionReferenceType',
+        args: Union[Tuple, List, None] = None,
+        kwargs: Optional[Dict] = None,
+        timeout: Optional[int] = None,
+        result_ttl: Optional[int] = None,
+        ttl: Optional[int] = None,
+        failure_ttl: Optional[int] = None,
+        description: Optional[str] = None,
+        depends_on: Optional['JobDependencyType'] = None,
+        job_id: Optional[str] = None,
+        at_front: bool = False,
+        meta: Optional[Dict] = None,
+        retry: Optional['Retry'] = None,
+        on_success: Optional[Callable[..., Any]] = None,
+        on_failure: Optional[Callable[..., Any]] = None,
+        pipeline: Optional['Pipeline'] = None,
     ) -> Job:
         """Creates a job to represent the delayed function call and enqueues it.
 
@@ -678,20 +688,20 @@ class Queue:
 
     @staticmethod
     def prepare_data(
-            func: 'FunctionReferenceType',
-            args: Union[Tuple, List, None] = None,
-            kwargs: Optional[Dict] = None,
-            timeout: Optional[int] = None,
-            result_ttl: Optional[int] = None,
-            ttl: Optional[int] = None,
-            failure_ttl: Optional[int] = None,
-            description: Optional[str] = None,
-            job_id: Optional[str] = None,
-            at_front: bool = False,
-            meta: Optional[Dict] = None,
-            retry: Optional['Retry'] = None,
-            on_success: Optional[Callable] = None,
-            on_failure: Optional[Callable] = None,
+        func: 'FunctionReferenceType',
+        args: Union[Tuple, List, None] = None,
+        kwargs: Optional[Dict] = None,
+        timeout: Optional[int] = None,
+        result_ttl: Optional[int] = None,
+        ttl: Optional[int] = None,
+        failure_ttl: Optional[int] = None,
+        description: Optional[str] = None,
+        job_id: Optional[str] = None,
+        at_front: bool = False,
+        meta: Optional[Dict] = None,
+        retry: Optional['Retry'] = None,
+        on_success: Optional[Callable] = None,
+        on_failure: Optional[Callable] = None,
     ) -> EnqueueData:
         """Need this till support dropped for python_version < 3.7, where defaults can be specified for named tuples
         And can keep this logic within EnqueueData
@@ -1003,7 +1013,6 @@ class Queue:
             return self._enqueue_job(job, pipeline=pipeline, at_front=at_front)
         return job
 
-
     def _enqueue_job(self, job: 'Job', pipeline: Optional['Pipeline'] = None, at_front: bool = False) -> Job:
         """Enqueues a job for delayed execution without checking dependencies.
 
@@ -1073,7 +1082,7 @@ class Queue:
         return job
 
     def enqueue_dependents(
-            self, job: 'Job', pipeline: Optional['Pipeline'] = None, exclude_job_id: Optional[str] = None
+        self, job: 'Job', pipeline: Optional['Pipeline'] = None, exclude_job_id: Optional[str] = None
     ):
         """Enqueues all jobs in the given job's dependents set and clears it.
 
@@ -1110,7 +1119,7 @@ class Queue:
                         dependent_job_ids, connection=self.connection, serializer=self.serializer
                     )
                     if dependent_job
-                       and dependent_job.dependencies_are_met(
+                    and dependent_job.dependencies_are_met(
                         parent_job=job,
                         pipeline=pipe,
                         exclude_job_id=exclude_job_id,
@@ -1210,13 +1219,13 @@ class Queue:
 
     @classmethod
     def dequeue_any(
-            cls,
-            queues: List['Queue'],
-            timeout: Optional[int],
-            connection: Optional['Redis'] = None,
-            job_class: Optional['Job'] = None,
-            serializer: Any = None,
-            death_penalty_class: Optional[Type[BaseDeathPenalty]] = None,
+        cls,
+        queues: List['Queue'],
+        timeout: Optional[int],
+        connection: Optional['Redis'] = None,
+        job_class: Optional['Job'] = None,
+        serializer: Any = None,
+        death_penalty_class: Optional[Type[BaseDeathPenalty]] = None,
     ) -> Tuple['Job', 'Queue']:
         """Class method returning the job_class instance at the front of the given
         set of Queues, where the order of the queues is important.
@@ -1250,8 +1259,13 @@ class Queue:
             if result is None:
                 return None
             queue_key, job_id = map(as_text, result)
-            queue = cls.from_queue_key(queue_key, connection=connection, job_class=job_class,
-                                       serializer=serializer, death_penalty_class=death_penalty_class)
+            queue = cls.from_queue_key(
+                queue_key,
+                connection=connection,
+                job_class=job_class,
+                serializer=serializer,
+                death_penalty_class=death_penalty_class,
+            )
             try:
                 job = job_class.fetch(job_id, connection=connection, serializer=serializer)
             except NoSuchJobError:

rq/utils.py

@@ -26,105 +26,6 @@ from .exceptions import TimeoutFormatError
 logger = logging.getLogger(__name__)
 
 
-class _Colorizer:
-    def __init__(self):
-        esc = "\x1b["
-
-        self.codes = {}
-        self.codes[""] = ""
-        self.codes["reset"] = esc + "39;49;00m"
-
-        self.codes["bold"] = esc + "01m"
-        self.codes["faint"] = esc + "02m"
-        self.codes["standout"] = esc + "03m"
-        self.codes["underline"] = esc + "04m"
-        self.codes["blink"] = esc + "05m"
-        self.codes["overline"] = esc + "06m"
-
-        dark_colors = ["black", "darkred", "darkgreen", "brown", "darkblue", "purple", "teal", "lightgray"]
-        light_colors = ["darkgray", "red", "green", "yellow", "blue", "fuchsia", "turquoise", "white"]
-
-        x = 30
-        for d, l in zip(dark_colors, light_colors):
-            self.codes[d] = esc + "%im" % x
-            self.codes[l] = esc + "%i;01m" % x
-            x += 1
-
-        del d, l, x
-
-        self.codes["darkteal"] = self.codes["turquoise"]
-        self.codes["darkyellow"] = self.codes["brown"]
-        self.codes["fuscia"] = self.codes["fuchsia"]
-        self.codes["white"] = self.codes["bold"]
-
-        if hasattr(sys.stdout, "isatty"):
-            self.notty = not sys.stdout.isatty()
-        else:
-            self.notty = True
-
-    def reset_color(self):
-        return self.codes["reset"]
-
-    def colorize(self, color_key, text):
-        if self.notty:
-            return text
-        else:
-            return self.codes[color_key] + text + self.codes["reset"]
-
-
-colorizer = _Colorizer()
-
-
-def make_colorizer(color: str):
-    """Creates a function that colorizes text with the given color.
-
-    For example::
-
-        ..codeblock::python
-
-            >>> green = make_colorizer('darkgreen')
-            >>> red = make_colorizer('red')
-            >>>
-            >>> # You can then use:
-            >>> print("It's either " + green('OK') + ' or ' + red('Oops'))
-    """
-
-    def inner(text):
-        return colorizer.colorize(color, text)
-
-    return inner
-
-
-class ColorizingStreamHandler(logging.StreamHandler):
-    levels = {
-        logging.WARNING: make_colorizer('darkyellow'),
-        logging.ERROR: make_colorizer('darkred'),
-        logging.CRITICAL: make_colorizer('darkred'),
-    }
-
-    def __init__(self, exclude=None, *args, **kwargs):
-        self.exclude = exclude
-        super().__init__(*args, **kwargs)
-
-    @property
-    def is_tty(self):
-        isatty = getattr(self.stream, 'isatty', None)
-        return isatty and isatty()
-
-    def format(self, record):
-        message = logging.StreamHandler.format(self, record)
-        if self.is_tty:
-            colorize = self.levels.get(record.levelno, lambda x: x)
-
-            # Don't colorize any traceback
-            parts = message.split('\n', 1)
-            parts[0] = " ".join([parts[0].split(" ", 1)[0], colorize(parts[0].split(" ", 1)[1])])
-
-            message = '\n'.join(parts)
-
-        return message
-
-
 def compact(lst: List[Any]) -> List[Any]:
     """Excludes `None` values from a list-like object.
 
@@ -137,7 +38,7 @@ def compact(lst: List[Any]) -> List[Any]:
     return [item for item in lst if item is not None]
 
 
-def as_text(v: Union[bytes, str]) -> Optional[str]:
+def as_text(v: Union[bytes, str]) -> str:
     """Converts a bytes value to a string using `utf-8`.
 
     Args:
@@ -149,9 +50,7 @@ def as_text(v: Union[bytes, str]) -> Optional[str]:
     Returns:
         value (Optional[str]): Either the decoded string or None
     """
-    if v is None:
-        return None
-    elif isinstance(v, bytes):
+    if isinstance(v, bytes):
         return v.decode('utf-8')
     elif isinstance(v, str):
         return v
@@ -181,7 +80,7 @@ def import_attribute(name: str) -> Callable[..., Any]:
     E.g.: package_a.package_b.module_a.ClassA.my_static_method
 
     Thus we remove the bits from the end of the name until we can import it
-    
+
     Args:
         name (str): The name (reference) to the path.
 

rq/worker.py

@@ -13,8 +13,7 @@ import warnings
 from datetime import timedelta
 from enum import Enum
 from random import shuffle
-from typing import (TYPE_CHECKING, Any, Callable, List, Optional, Tuple, Type,
-                    Union)
+from typing import TYPE_CHECKING, Any, Callable, List, Optional, Tuple, Type, Union
 from uuid import uuid4
 
 if TYPE_CHECKING:
@@ -50,14 +49,23 @@ from .defaults import (
 from .exceptions import DeserializationError, DequeueTimeout, ShutDownImminentException
 
 from .job import Job, JobStatus
-from .logutils import setup_loghandlers
+from .logutils import blue, green, setup_loghandlers, yellow
 from .queue import Queue
 from .registry import StartedJobRegistry, clean_registries
 from .scheduler import RQScheduler
 from .serializers import resolve_serializer
 from .suspension import is_suspended
 from .timeouts import JobTimeoutException, HorseMonitorTimeoutException, UnixSignalDeathPenalty
-from .utils import backend_class, ensure_list, get_version, make_colorizer, utcformat, utcnow, utcparse, compact, as_text
+from .utils import (
+    backend_class,
+    ensure_list,
+    get_version,
+    utcformat,
+    utcnow,
+    utcparse,
+    compact,
+    as_text,
+)
 from .version import VERSION
 from .serializers import resolve_serializer
 
@@ -70,10 +78,6 @@ except ImportError:
         pass
 
 
-green = make_colorizer('darkgreen')
-yellow = make_colorizer('darkyellow')
-blue = make_colorizer('darkblue')
-
 logger = logging.getLogger("rq.worker")
 
 
@@ -112,12 +116,13 @@ class WorkerStatus(str, Enum):
     IDLE = 'idle'
 
 
-class Worker:
+class BaseWorker:
     redis_worker_namespace_prefix = 'rq:worker:'
     redis_workers_keys = worker_registration.REDIS_WORKER_KEYS
     death_penalty_class = UnixSignalDeathPenalty
     queue_class = Queue
     job_class = Job
+
     # `log_result_lifespan` controls whether "Result is kept for XXX seconds"
     # messages are logged after every job, by default they are.
     log_result_lifespan = True
@@ -182,6 +187,51 @@ class Worker:
         """
         return len(worker_registration.get_keys(queue=queue, connection=connection))
 
+    def get_redis_server_version(self):
+        """Return Redis server version of connection"""
+        if not self.redis_server_version:
+            self.redis_server_version = get_version(self.connection)
+        return self.redis_server_version
+
+    def validate_queues(self):
+        """Sanity check for the given queues."""
+        for queue in self.queues:
+            if not isinstance(queue, self.queue_class):
+                raise TypeError('{0} is not of type {1} or string types'.format(queue, self.queue_class))
+
+    def queue_names(self) -> List[str]:
+        """Returns the queue names of this worker's queues.
+
+        Returns:
+            List[str]: The queue names.
+        """
+        return [queue.name for queue in self.queues]
+
+    def queue_keys(self) -> List[str]:
+        """Returns the Redis keys representing this worker's queues.
+
+        Returns:
+            List[str]: The list of strings with queues keys
+        """
+        return [queue.key for queue in self.queues]
+
+    @property
+    def key(self):
+        """Returns the worker's Redis hash key."""
+        return self.redis_worker_namespace_prefix + self.name
+
+    @property
+    def pubsub_channel_name(self):
+        """Returns the worker's Redis hash key."""
+        return PUBSUB_CHANNEL_TEMPLATE % self.name
+
+    @property
+    def supports_redis_streams(self) -> bool:
+        """Only supported by Redis server >= 5.0 is required."""
+        return self.get_redis_server_version() >= (5, 0, 0)
+
+
+class Worker(BaseWorker):
     @classmethod
     def find_by_key(
         cls,
@@ -249,7 +299,7 @@ class Worker:
         disable_default_exception_handler: bool = False,
         prepare_for_work: bool = True,
         serializer=None,
-        work_horse_killed_handler: Optional[Callable[[Job, int, int, 'struct_rusage'], None]] = None
+        work_horse_killed_handler: Optional[Callable[[Job, int, int, 'struct_rusage'], None]] = None,
     ):  # noqa
         self.default_result_ttl = default_result_ttl
         self.worker_ttl = default_worker_ttl
@@ -267,8 +317,13 @@ class Worker:
         self.serializer = resolve_serializer(serializer)
 
         queues = [
-            self.queue_class(name=q, connection=connection, job_class=self.job_class,
-                             serializer=self.serializer, death_penalty_class=self.death_penalty_class,)
+            self.queue_class(
+                name=q,
+                connection=connection,
+                job_class=self.job_class,
+                serializer=self.serializer,
+                death_penalty_class=self.death_penalty_class,
+            )
             if isinstance(q, str)
             else q
             for q in ensure_list(queues)
@@ -344,49 +399,6 @@ class Worker:
             connection.connection_pool.connection_kwargs.update(timeout_config)
         return connection
 
-    def get_redis_server_version(self):
-        """Return Redis server version of connection"""
-        if not self.redis_server_version:
-            self.redis_server_version = get_version(self.connection)
-        return self.redis_server_version
-
-    def validate_queues(self):
-        """Sanity check for the given queues."""
-        for queue in self.queues:
-            if not isinstance(queue, self.queue_class):
-                raise TypeError('{0} is not of type {1} or string types'.format(queue, self.queue_class))
-
-    def queue_names(self) -> List[str]:
-        """Returns the queue names of this worker's queues.
-
-        Returns:
-            List[str]: The queue names.
-        """
-        return [queue.name for queue in self.queues]
-
-    def queue_keys(self) -> List[str]:
-        """Returns the Redis keys representing this worker's queues.
-
-        Returns:
-            List[str]: The list of strings with queues keys
-        """
-        return [queue.key for queue in self.queues]
-
-    @property
-    def key(self):
-        """Returns the worker's Redis hash key."""
-        return self.redis_worker_namespace_prefix + self.name
-
-    @property
-    def pubsub_channel_name(self):
-        """Returns the worker's Redis hash key."""
-        return PUBSUB_CHANNEL_TEMPLATE % self.name
-
-    @property
-    def supports_redis_streams(self) -> bool:
-        """Only supported by Redis server >= 5.0 is required."""
-        return self.get_redis_server_version() >= (5, 0, 0)
-
     @property
     def horse_pid(self):
         """The horse's process ID.  Only available in the worker.  Will return
@@ -538,7 +550,10 @@ class Worker:
             job_id (Optional[str): The job id
         """
         connection = pipeline if pipeline is not None else self.connection
-        return as_text(connection.hget(self.key, 'current_job'))
+        result = connection.hget(self.key, 'current_job')
+        if result is None:
+            return None
+        return as_text(result)
 
     def get_current_job(self) -> Optional['Job']:
         """Returns the currently executing job instance.
@@ -706,7 +721,7 @@ class Worker:
             return
         if self._dequeue_strategy == DequeueStrategy.ROUND_ROBIN:
             pos = self._ordered_queues.index(reference_queue)
-            self._ordered_queues = self._ordered_queues[pos + 1:] + self._ordered_queues[: pos + 1]
+            self._ordered_queues = self._ordered_queues[pos + 1 :] + self._ordered_queues[: pos + 1]
             return
         if self._dequeue_strategy == DequeueStrategy.RANDOM:
             shuffle(self._ordered_queues)
@@ -716,7 +731,7 @@ class Worker:
         self,
         logging_level: str = "INFO",
         date_format: str = DEFAULT_LOGGING_DATE_FORMAT,
-        log_format: str = DEFAULT_LOGGING_FORMAT
+        log_format: str = DEFAULT_LOGGING_FORMAT,
     ):
         """Bootstraps the worker.
         Runs the basic tasks that should run when the worker actually starts working.
@@ -781,7 +796,7 @@ class Worker:
         max_jobs: Optional[int] = None,
         max_idle_time: Optional[int] = None,
         with_scheduler: bool = False,
-        dequeue_strategy: DequeueStrategy = DequeueStrategy.DEFAULT
+        dequeue_strategy: DequeueStrategy = DequeueStrategy.DEFAULT,
     ) -> bool:
         """Starts the work loop.
 
@@ -881,7 +896,9 @@ class Worker:
                 pass
             self.scheduler._process.join()
 
-    def dequeue_job_and_maintain_ttl(self, timeout: Optional[int], max_idle_time: Optional[int] = None) -> Tuple['Job', 'Queue']:
+    def dequeue_job_and_maintain_ttl(
+        self, timeout: Optional[int], max_idle_time: Optional[int] = None
+    ) -> Tuple['Job', 'Queue']:
         """Dequeues a job while maintaining the TTL.
 
         Returns:
@@ -1167,10 +1184,7 @@ class Worker:
             self.log.warning('Moving job to FailedJobRegistry (%s)', exc_string)
 
             self.handle_work_horse_killed(job, retpid, ret_val, rusage)
-            self.handle_job_failure(
-                job, queue=queue,
-                exc_string=exc_string
-            )
+            self.handle_job_failure(job, queue=queue, exc_string=exc_string)
 
     def execute_job(self, job: 'Job', queue: 'Queue'):
         """Spawns a work horse to perform the actual work and passes it a job.
@@ -1458,9 +1472,7 @@ class Worker:
         extra.update({'queue': job.origin, 'job_id': job.id})
 
         # func_name
-        self.log.error(
-            '[Job %s]: exception raised while executing (%s)\n' + exc_string, job.id, func_name, extra=extra
-        )
+        self.log.error('[Job %s]: exception raised while executing (%s)\n' + exc_string, job.id, func_name, extra=extra)
 
         for handler in self._exc_handlers:
             self.log.debug('Invoking exception handler %s', handler)
@@ -1598,7 +1610,7 @@ class RoundRobinWorker(Worker):
 
     def reorder_queues(self, reference_queue):
         pos = self._ordered_queues.index(reference_queue)
-        self._ordered_queues = self._ordered_queues[pos + 1:] + self._ordered_queues[: pos + 1]
+        self._ordered_queues = self._ordered_queues[pos + 1 :] + self._ordered_queues[: pos + 1]
 
 
 class RandomWorker(Worker):