fix(loguru): Move integration setup from __init__ to setup_once (#4399)

We shouldn't have setup code in an integration's `__init__`. This can be
called an arbitrary amount of times. `setup_once` exists so that the
code is only guaranteed to run once.

Having integration setup in `__init__` also means that the integration
currently can't be disabled via `disabled_integrations`.

Fixes #4398

Author: sentrivana

sentry_sdk/integrations/loguru.py

@@ -11,7 +11,7 @@
 
 if TYPE_CHECKING:
     from logging import LogRecord
-    from typing import Optional, Tuple, Any
+    from typing import Optional, Any
 
 try:
     import loguru
@@ -43,16 +43,16 @@ class LoggingLevels(enum.IntEnum):
 
 DEFAULT_LEVEL = LoggingLevels.INFO.value
 DEFAULT_EVENT_LEVEL = LoggingLevels.ERROR.value
-# We need to save the handlers to be able to remove them later
-# in tests (they call `LoguruIntegration.__init__` multiple times,
-# and we can't use `setup_once` because it's called before
-# than we get configuration).
-_ADDED_HANDLERS = (None, None)  # type: Tuple[Optional[int], Optional[int]]
 
 
 class LoguruIntegration(Integration):
     identifier = "loguru"
 
+    level = DEFAULT_LEVEL  # type: Optional[int]
+    event_level = DEFAULT_EVENT_LEVEL  # type: Optional[int]
+    breadcrumb_format = DEFAULT_FORMAT
+    event_format = DEFAULT_FORMAT
+
     def __init__(
         self,
         level=DEFAULT_LEVEL,
@@ -61,36 +61,27 @@ def __init__(
         event_format=DEFAULT_FORMAT,
     ):
         # type: (Optional[int], Optional[int], str | loguru.FormatFunction, str | loguru.FormatFunction) -> None
-        global _ADDED_HANDLERS
-        breadcrumb_handler, event_handler = _ADDED_HANDLERS
-
-        if breadcrumb_handler is not None:
-            logger.remove(breadcrumb_handler)
-            breadcrumb_handler = None
-        if event_handler is not None:
-            logger.remove(event_handler)
-            event_handler = None
-
-        if level is not None:
-            breadcrumb_handler = logger.add(
-                LoguruBreadcrumbHandler(level=level),
-                level=level,
-                format=breadcrumb_format,
-            )
-
-        if event_level is not None:
-            event_handler = logger.add(
-                LoguruEventHandler(level=event_level),
-                level=event_level,
-                format=event_format,
-            )
-
-        _ADDED_HANDLERS = (breadcrumb_handler, event_handler)
+        LoguruIntegration.level = level
+        LoguruIntegration.event_level = event_level
+        LoguruIntegration.breadcrumb_format = breadcrumb_format
+        LoguruIntegration.event_format = event_format
 
     @staticmethod
     def setup_once():
         # type: () -> None
-        pass  # we do everything in __init__
+        if LoguruIntegration.level is not None:
+            logger.add(
+                LoguruBreadcrumbHandler(level=LoguruIntegration.level),
+                level=LoguruIntegration.level,
+                format=LoguruIntegration.breadcrumb_format,
+            )
+
+        if LoguruIntegration.event_level is not None:
+            logger.add(
+                LoguruEventHandler(level=LoguruIntegration.event_level),
+                level=LoguruIntegration.event_level,
+                format=LoguruIntegration.event_format,
+            )
 
 
 class _LoguruBaseHandler(_BaseHandler):

tests/integrations/loguru/test_loguru.py

@@ -32,7 +32,12 @@ def test_just_log(
     expected_sentry_level,
     disable_breadcrumbs,
     disable_events,
+    uninstall_integration,
+    request,
 ):
+    uninstall_integration("loguru")
+    request.addfinalizer(logger.remove)
+
     sentry_init(
         integrations=[
             LoguruIntegration(
@@ -49,7 +54,7 @@ def test_just_log(
     formatted_message = (
         " | "
         + "{:9}".format(level.name.upper())
-        + "| tests.integrations.loguru.test_loguru:test_just_log:47 - test"
+        + "| tests.integrations.loguru.test_loguru:test_just_log:52 - test"
     )
 
     if not created_event:
@@ -78,7 +83,10 @@ def test_just_log(
     assert event["logentry"]["message"][23:] == formatted_message
 
 
-def test_breadcrumb_format(sentry_init, capture_events):
+def test_breadcrumb_format(sentry_init, capture_events, uninstall_integration, request):
+    uninstall_integration("loguru")
+    request.addfinalizer(logger.remove)
+
     sentry_init(
         integrations=[
             LoguruIntegration(
@@ -98,7 +106,10 @@ def test_breadcrumb_format(sentry_init, capture_events):
     assert breadcrumb["message"] == formatted_message
 
 
-def test_event_format(sentry_init, capture_events):
+def test_event_format(sentry_init, capture_events, uninstall_integration, request):
+    uninstall_integration("loguru")
+    request.addfinalizer(logger.remove)
+
     sentry_init(
         integrations=[
             LoguruIntegration(