pylint-dev · DanielNoord · Mar 30, 2025 · Mar 30, 2025 · Mar 30, 2025
diff --git a/doc/whatsnew/fragments/9999.false_negative b/doc/whatsnew/fragments/9999.false_negative
@@ -0,0 +1,5 @@
+We now raise a ``logging-too-few-args`` for format string with no
+interpolation arguments at all (i.e. for something like ``logging.debug("Awaiting process %s")``
+or ``logging.debug("Awaiting process {pid}")``). Previously we did not raise for such case.
+
+Closes #9999
diff --git a/pylint/checkers/logging.py b/pylint/checkers/logging.py
@@ -326,11 +326,6 @@ def _check_format_string(self, node: nodes.Call, format_arg: Literal[0, 1]) -> N
           format_arg: Index of the format string in the node arguments.
         """
         num_args = _count_supplied_tokens(node.args[format_arg + 1 :])
-        if not num_args:
-            # If no args were supplied the string is not interpolated and can contain
-            # formatting characters - it's used verbatim. Don't check any further.
-            return
-
         format_string = node.args[format_arg].value
         required_num_args = 0
         if isinstance(format_string, bytes):

diff --git a/tests/config/data/logging_format_interpolation_style.py b/tests/config/data/logging_format_interpolation_style.py
@@ -5,7 +5,6 @@
 import logging
 
 logging.error("constant string")
-logging.error("{}")
 logging.error("{}", 1)
 logging.error("{0}", 1)
 logging.error("{named}", {"named": 1})

diff --git a/tests/functional/l/logging/logging_format_interpolation_style.py b/tests/functional/l/logging/logging_format_interpolation_style.py
@@ -3,7 +3,6 @@
 import logging
 
 logging.error("constant string")
-logging.error("{}")
 logging.error("{}", 1)
 logging.error("{0}", 1)
 logging.error("{named}", {"named": 1})

diff --git a/tests/functional/l/logging/logging_too_few_args.txt b/tests/functional/l/logging/logging_too_few_args.txt
diff --git a/...ctional/l/logging/logging_too_few_args.py → ...logging/logging_too_few_args_new_style.py b/...ctional/l/logging/logging_too_few_args.py → ...logging/logging_too_few_args_new_style.py
@@ -1,9 +1,12 @@
-"""Tests for logging-too-few-args"""
+"""Tests for logging-too-few-args new style"""
 
 import logging
 
 logging.error("{}, {}", 1)  # [logging-too-few-args]
 logging.error("{0}, {1}", 1)  # [logging-too-few-args]
+logging.error("{}")  # [logging-too-few-args]
+logging.error("{0}")  # [logging-too-few-args]
+logging.error("{named}")  # [logging-too-few-args]
 logging.error("{named1}, {named2}", {"named1": 1})  # [logging-too-few-args]
 logging.error("{0}, {named}", 1)  # [logging-too-few-args]
 logging.error("{}, {named}", {"named": 1})  # [logging-too-few-args]

diff --git a/...ctional/l/logging/logging_too_few_args.rc → ...logging/logging_too_few_args_new_style.rc b/...ctional/l/logging/logging_too_few_args.rc → ...logging/logging_too_few_args_new_style.rc
diff --git a/tests/functional/l/logging/logging_too_few_args_new_style.txt b/tests/functional/l/logging/logging_too_few_args_new_style.txt
@@ -0,0 +1,9 @@
+logging-too-few-args:5:0:5:26::Not enough arguments for logging format string:UNDEFINED
+logging-too-few-args:6:0:6:28::Not enough arguments for logging format string:UNDEFINED
+logging-too-few-args:7:0:7:19::Not enough arguments for logging format string:UNDEFINED
+logging-too-few-args:8:0:8:20::Not enough arguments for logging format string:UNDEFINED
+logging-too-few-args:9:0:9:24::Not enough arguments for logging format string:UNDEFINED
+logging-too-few-args:10:0:10:50::Not enough arguments for logging format string:UNDEFINED
+logging-too-few-args:11:0:11:32::Not enough arguments for logging format string:UNDEFINED
+logging-too-few-args:12:0:12:42::Not enough arguments for logging format string:UNDEFINED
+logging-too-few-args:13:0:13:43::Not enough arguments for logging format string:UNDEFINED
diff --git a/tests/functional/l/logging/logging_too_few_args_old_style.py b/tests/functional/l/logging/logging_too_few_args_old_style.py
@@ -0,0 +1,6 @@
+"""Tests for logging-too-few-args old style"""
+
+import logging
+
+logging.error("%s, %s", 1)  # [logging-too-few-args]
+logging.debug("Sisyphus table %s: sleep")  # [logging-too-few-args]
diff --git a/tests/functional/l/logging/logging_too_few_args_old_style.rc b/tests/functional/l/logging/logging_too_few_args_old_style.rc
@@ -0,0 +1,2 @@
+[LOGGING]
+logging-format-style=old
diff --git a/tests/functional/l/logging/logging_too_few_args_old_style.txt b/tests/functional/l/logging/logging_too_few_args_old_style.txt
@@ -0,0 +1,2 @@
+logging-too-few-args:5:0:5:26::Not enough arguments for logging format string:UNDEFINED
+logging-too-few-args:6:0:6:41::Not enough arguments for logging format string:UNDEFINED
diff --git a/tests/functional/s/string/string_log_formatting.py b/tests/functional/s/string/string_log_formatting.py
@@ -22,7 +22,7 @@ def pprint():
     logging.info(1)
     logging.info(True)
     logging.info('')
-    logging.info('%s%')
+    logging.info('%s%')  # [logging-format-truncated]
     logging.info('%s', '')
     logging.info('%s%%', '')
     logging.info('%s%s', '', '')
diff --git a/tests/functional/s/string/string_log_formatting.txt b/tests/functional/s/string/string_log_formatting.txt
@@ -4,3 +4,4 @@ logging-format-truncated:16:4:16:27:pprint:Logging format string ends in middle
 logging-too-few-args:17:4:17:28:pprint:Not enough arguments for logging format string:UNDEFINED
 logging-unsupported-format:18:4:18:32:pprint:Unsupported logging format character 'y' (0x79) at index 3:UNDEFINED
 logging-too-many-args:19:4:19:36:pprint:Too many arguments for logging format string:HIGH
+logging-format-truncated:25:4:25:23:pprint:Logging format string ends in middle of conversion specifier:UNDEFINED
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1,2 @@
		logging-too-few-args:5:0:5:26::Not enough arguments for logging format string:UNDEFINED
		logging-too-few-args:6:0:6:41::Not enough arguments for logging format string:UNDEFINED