Brought back logging-fstring-interpolation

12 files changed, 113 insertions, 112 deletions

diff --git a/ChangeLog b/ChangeLog
index f8d322ef6..22d2cf50e 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -275,6 +275,13 @@ Release date: TBA
   Close #1482
   Close #1553
 
+* Multiple types of string formatting are allowed in logging functions.
+
+  The `logging-fstring-interpolation` message has been brought back to allow
+  multiple types of string formatting to be used.
+
+  Close #3361
+
 What's New in Pylint 2.4.4?
 ===========================
 Release date: 2019-11-13
diff --git a/doc/whatsnew/2.5.rst b/doc/whatsnew/2.5.rst
index 178b8c34b..35ffbbdcc 100644
--- a/doc/whatsnew/2.5.rst
+++ b/doc/whatsnew/2.5.rst
@@ -92,3 +92,11 @@ Other Changes
   This command lists all extensions present in ``pylint.extensions``.
 
 * Various false positives have been fixed which you can read more about in the Changelog files.
+
+* Multiple types of string formatting are allowed in logging functions.
+
+The `logging-fstring-interpolation` message has been brought back to allow
+multiple types of string formatting to be used.
+The type of formatting to use is chosen through enabling and disabling messages
+rather than through the logging-format-style option.
+The fstr value of the logging-format-style option is not valid.
diff --git a/pylint/checkers/logging.py b/pylint/checkers/logging.py
index 9a2ab95d3..5de0340d5 100644
--- a/pylint/checkers/logging.py
+++ b/pylint/checkers/logging.py
@@ -26,25 +26,43 @@ from pylint.checkers.utils import check_messages
 
 MSGS = {
     "W1201": (
-        "Specify string format arguments as logging function parameters",
+        "Use %s formatting in logging functions",
         "logging-not-lazy",
         "Used when a logging statement has a call form of "
         '"logging.<logging method>(format_string % (format_args...))". '
-        "Such calls should leave string interpolation to the logging "
-        "method itself and be written "
-        '"logging.<logging method>(format_string, format_args...)" '
-        "so that the program may avoid incurring the cost of the "
-        "interpolation in those cases in which no message will be "
-        "logged. For more, see "
-        "http://www.python.org/dev/peps/pep-0282/.",
+        "Use another type of string formatting instead. "
+        "You can use % formatting but leave interpolation to "
+        "the logging function by passing the parameters as arguments. "
+        "If logging-fstring-interpolation is disabled then "
+        "you can use fstring formatting. "
+        "If logging-format-interpolation is disabled then "
+        "you can use str.format.",
     ),
     "W1202": (
-        "Use %s formatting in logging functions%s",
+        "Use %s formatting in logging functions",
         "logging-format-interpolation",
         "Used when a logging statement has a call form of "
-        '"logging.<logging method>(<string formatting>)".'
-        " with invalid string formatting. "
-        "Use another way for format the string instead.",
+        '"logging.<logging method>(format_string.format(format_args...))". '
+        "Use another type of string formatting instead. "
+        "You can use % formatting but leave interpolation to "
+        "the logging function by passing the parameters as arguments. "
+        "If logging-fstring-interpolation is disabled then "
+        "you can use fstring formatting. "
+        "If logging-not-lazy is disabled then "
+        "you can use % formatting as normal.",
+    ),
+    "W1203": (
+        "Use %s formatting in logging functions",
+        "logging-fstring-interpolation",
+        "Used when a logging statement has a call form of "
+        '"logging.<logging method>(f"...")".'
+        "Use another type of string formatting instead. "
+        "You can use % formatting but leave interpolation to "
+        "the logging function by passing the parameters as arguments. "
+        "If logging-format-interpolation is disabled then "
+        "you can use str.format. "
+        "If logging-not-lazy is disabled then "
+        "you can use % formatting as normal.",
     ),
     "E1200": (
         "Unsupported logging format character %r (%#02x) at index %d",
@@ -126,11 +144,10 @@ class LoggingChecker(checkers.BaseChecker):
             {
                 "default": "old",
                 "type": "choice",
-                "metavar": "<old (%) or new ({) or fstr (f'')>",
-                "choices": ["old", "new", "fstr"],
-                "help": "Format style used to check logging format string. "
-                "`old` means using % formatting, `new` is for `{}` formatting,"
-                "and `fstr` is for f-strings.",
+                "metavar": "<old (%) or new ({)>",
+                "choices": ["old", "new"],
+                "help": "The type of string formatting that logging methods do. "
+                "`old` means using % formatting, `new` is for `{}` formatting.",
             },
         ),
     )
@@ -144,12 +161,6 @@ class LoggingChecker(checkers.BaseChecker):
         logging_mods = self.config.logging_modules
 
         self._format_style = self.config.logging_format_style
-        format_styles = {"old": "%", "new": "{", "fstr": "f-string"}
-        format_style_help = ""
-        if self._format_style == "old":
-            format_style_help = " and pass the % parameters as arguments"
-
-        self._format_style_args = (format_styles[self._format_style], format_style_help)
 
         self._logging_modules = set(logging_mods)
         self._from_imports = {}
@@ -238,20 +249,36 @@ class LoggingChecker(checkers.BaseChecker):
                 )
                 emit = total_number_of_strings > 0
             if emit:
-                self.add_message("logging-not-lazy", node=node)
+                self.add_message(
+                    "logging-not-lazy", node=node, args=(self._helper_string(node),),
+                )
         elif isinstance(node.args[format_pos], astroid.Call):
             self._check_call_func(node.args[format_pos])
         elif isinstance(node.args[format_pos], astroid.Const):
             self._check_format_string(node, format_pos)
-        elif isinstance(
-            node.args[format_pos], (astroid.FormattedValue, astroid.JoinedStr)
+        elif isinstance(node.args[format_pos], astroid.JoinedStr):
+            self.add_message(
+                "logging-fstring-interpolation",
+                node=node,
+                args=(self._helper_string(node),),
+            )
+
+    def _helper_string(self, node):
+        """Create a string that lists the valid types of formatting for this node."""
+        valid_types = ["lazy %"]
+
+        if not self.linter.is_message_enabled(
+            "logging-fstring-formatting", node.fromlineno
         ):
-            if self._format_style != "fstr":
-                self.add_message(
-                    "logging-format-interpolation",
-                    node=node,
-                    args=self._format_style_args,
-                )
+            valid_types.append("fstring")
+        if not self.linter.is_message_enabled(
+            "logging-format-formatting", node.fromlineno
+        ):
+            valid_types.append(".format()")
+        if not self.linter.is_message_enabled("logging-not-lazy", node.fromlineno):
+            valid_types.append("%")
+
+        return " or ".join(valid_types)
 
     @staticmethod
     def _is_operand_literal_str(operand):
@@ -274,7 +301,9 @@ class LoggingChecker(checkers.BaseChecker):
             func.bound
         ):
             self.add_message(
-                "logging-format-interpolation", node=node, args=self._format_style_args
+                "logging-format-interpolation",
+                node=node,
+                args=(self._helper_string(node),),
             )
 
     def _check_format_string(self, node, format_arg):
@@ -317,13 +346,6 @@ class LoggingChecker(checkers.BaseChecker):
                     required_num_args = (
                         keyword_args_cnt + implicit_pos_args + explicit_pos_args
                     )
-                else:
-                    self.add_message(
-                        "logging-format-interpolation",
-                        node=node,
-                        args=self._format_style_args,
-                    )
-                    return
             except utils.UnsupportedFormatCharacter as ex:
                 char = format_string[ex.index]
                 self.add_message(
diff --git a/tests/functional/l/logging_format_interpolation.txt b/tests/functional/l/logging_format_interpolation.txt
index 36051253c..1b27530b7 100644
--- a/tests/functional/l/logging_format_interpolation.txt
+++ b/tests/functional/l/logging_format_interpolation.txt
@@ -1,5 +1,5 @@
-logging-format-interpolation:16::Use % formatting in logging functions and pass the % parameters as arguments
-logging-format-interpolation:17::Use % formatting in logging functions and pass the % parameters as arguments
-logging-format-interpolation:18::Use % formatting in logging functions and pass the % parameters as arguments
-logging-format-interpolation:19::Use % formatting in logging functions and pass the % parameters as arguments
-logging-format-interpolation:20::Use % formatting in logging functions and pass the % parameters as arguments
+logging-format-interpolation:16::Use lazy % formatting in logging functions
+logging-format-interpolation:17::Use lazy % formatting in logging functions
+logging-format-interpolation:18::Use lazy % formatting in logging functions
+logging-format-interpolation:19::Use lazy % formatting in logging functions
+logging-format-interpolation:20::Use lazy % formatting in logging functions
diff --git a/tests/functional/l/logging_format_interpolation_py36.py b/tests/functional/l/logging_format_interpolation_py36.py
index 92958ae5a..2601c5bfc 100644
--- a/tests/functional/l/logging_format_interpolation_py36.py
+++ b/tests/functional/l/logging_format_interpolation_py36.py
@@ -1,5 +1,5 @@
-"""Test logging-format-interpolation for Python 3.6"""
+"""Test logging-fstring-interpolation for Python 3.6"""
 import logging as renamed_logging
 
 
-renamed_logging.info(f'Read {renamed_logging} from globals')  # [logging-format-interpolation]
+renamed_logging.info(f'Read {renamed_logging} from globals')  # [logging-fstring-interpolation]
diff --git a/tests/functional/l/logging_format_interpolation_py36.txt b/tests/functional/l/logging_format_interpolation_py36.txt
index 7a7dc06c0..bc185c975 100644
--- a/tests/functional/l/logging_format_interpolation_py36.txt
+++ b/tests/functional/l/logging_format_interpolation_py36.txt
@@ -1 +1 @@
-logging-format-interpolation:5::Use % formatting in logging functions and pass the % parameters as arguments
+logging-fstring-interpolation:5::Use lazy % formatting in logging functions
diff --git a/tests/functional/l/logging_fstring_interpolation_py36.py b/tests/functional/l/logging_fstring_interpolation_py36.py
index 68eaba22f..5aebb7dd2 100644
--- a/tests/functional/l/logging_fstring_interpolation_py36.py
+++ b/tests/functional/l/logging_fstring_interpolation_py36.py
@@ -1,4 +1,4 @@
-"""Test logging-format-interpolation for Python 3.6"""
+"""Test logging-fstring-interpolation for Python 3.6"""
 # pylint: disable=invalid-name
 
 from datetime import datetime
@@ -14,8 +14,8 @@ pi = 3.14159265
 may_14 = datetime(year=2018, month=5, day=14)
 
 # Statements that should be flagged:
-renamed_logging.debug(f'{local_var_1} {local_var_2}') # [logging-format-interpolation]
-renamed_logging.log(renamed_logging.DEBUG, f'msg: {local_var_2}') # [logging-format-interpolation]
-renamed_logging.log(renamed_logging.DEBUG, f'pi: {pi:.3f}') # [logging-format-interpolation]
-renamed_logging.info(f"{local_var_2.upper()}") # [logging-format-interpolation]
-renamed_logging.info(f"{may_14:'%b %d: %Y'}") # [logging-format-interpolation]
+renamed_logging.debug(f'{local_var_1} {local_var_2}') # [logging-fstring-interpolation]
+renamed_logging.log(renamed_logging.DEBUG, f'msg: {local_var_2}') # [logging-fstring-interpolation]
+renamed_logging.log(renamed_logging.DEBUG, f'pi: {pi:.3f}') # [logging-fstring-interpolation]
+renamed_logging.info(f"{local_var_2.upper()}") # [logging-fstring-interpolation]
+renamed_logging.info(f"{may_14:'%b %d: %Y'}") # [logging-fstring-interpolation]
diff --git a/tests/functional/l/logging_fstring_interpolation_py36.txt b/tests/functional/l/logging_fstring_interpolation_py36.txt
index a8c6fd5cd..e0c445c4b 100644
--- a/tests/functional/l/logging_fstring_interpolation_py36.txt
+++ b/tests/functional/l/logging_fstring_interpolation_py36.txt
@@ -1,5 +1,5 @@
-logging-format-interpolation:17::Use % formatting in logging functions and pass the % parameters as arguments
-logging-format-interpolation:18::Use % formatting in logging functions and pass the % parameters as arguments
-logging-format-interpolation:19::Use % formatting in logging functions and pass the % parameters as arguments
-logging-format-interpolation:20::Use % formatting in logging functions and pass the % parameters as arguments
-logging-format-interpolation:21::Use % formatting in logging functions and pass the % parameters as arguments
+logging-fstring-interpolation:17::Use lazy % formatting in logging functions
+logging-fstring-interpolation:18::Use lazy % formatting in logging functions
+logging-fstring-interpolation:19::Use lazy % formatting in logging functions
+logging-fstring-interpolation:20::Use lazy % formatting in logging functions
+logging-fstring-interpolation:21::Use lazy % formatting in logging functions
diff --git a/tests/functional/l/logging_not_lazy.txt b/tests/functional/l/logging_not_lazy.txt
index 31e7cc448..95ef675b2 100644
--- a/tests/functional/l/logging_not_lazy.txt
+++ b/tests/functional/l/logging_not_lazy.txt
@@ -1,6 +1,6 @@
-logging-not-lazy:10::Specify string format arguments as logging function parameters
-logging-not-lazy:11::Specify string format arguments as logging function parameters
-logging-not-lazy:12::Specify string format arguments as logging function parameters
-logging-not-lazy:13::Specify string format arguments as logging function parameters
-logging-not-lazy:14::Specify string format arguments as logging function parameters
-logging-not-lazy:15::Specify string format arguments as logging function parameters
+logging-not-lazy:10::Use lazy % formatting in logging functions
+logging-not-lazy:11::Use lazy % formatting in logging functions
+logging-not-lazy:12::Use lazy % formatting in logging functions
+logging-not-lazy:13::Use lazy % formatting in logging functions
+logging-not-lazy:14::Use lazy % formatting in logging functions
+logging-not-lazy:15::Use lazy % formatting in logging functions
diff --git a/tests/messages/func_bug113231.txt b/tests/messages/func_bug113231.txt
index a9d3f7ef3..f05f16020 100644
--- a/tests/messages/func_bug113231.txt
+++ b/tests/messages/func_bug113231.txt
@@ -1,2 +1,2 @@
-W: 20: Specify string format arguments as logging function parameters
-W: 21: Specify string format arguments as logging function parameters
+W: 20: Use lazy % formatting in logging functions
+W: 21: Use lazy % formatting in logging functions
diff --git a/tests/messages/func_logging_not_lazy_with_logger.txt b/tests/messages/func_logging_not_lazy_with_logger.txt
index 04823cf33..22e7bc6af 100644
--- a/tests/messages/func_logging_not_lazy_with_logger.txt
+++ b/tests/messages/func_logging_not_lazy_with_logger.txt
@@ -1,4 +1,4 @@
-W:  8: Specify string format arguments as logging function parameters
-W:  9: Specify string format arguments as logging function parameters
-W: 11: Specify string format arguments as logging function parameters
-W: 13: Specify string format arguments as logging function parameters
+W:  8: Use lazy % formatting in logging functions
+W:  9: Use lazy % formatting in logging functions
+W: 11: Use lazy % formatting in logging functions
+W: 13: Use lazy % formatting in logging functions
diff --git a/tests/unittest_checker_logging.py b/tests/unittest_checker_logging.py
index 50ba2100f..a025fb6a2 100644
--- a/tests/unittest_checker_logging.py
+++ b/tests/unittest_checker_logging.py
@@ -30,7 +30,7 @@ class TestLoggingModuleDetection(CheckerTestCase):
         )
         self.checker.visit_module(None)
         self.checker.visit_import(stmts[0])
-        with self.assertAddsMessages(Message("logging-not-lazy", node=stmts[1])):
+        with self.assertAddsMessages(Message("logging-not-lazy", node=stmts[1], args=("lazy %",))):
             self.checker.visit_call(stmts[1])
 
     def test_dont_crash_on_invalid_format_string(self):
@@ -51,7 +51,7 @@ class TestLoggingModuleDetection(CheckerTestCase):
         )
         self.checker.visit_module(None)
         self.checker.visit_import(stmts[0])
-        with self.assertAddsMessages(Message("logging-not-lazy", node=stmts[1])):
+        with self.assertAddsMessages(Message("logging-not-lazy", node=stmts[1], args=("lazy %",))):
             self.checker.visit_call(stmts[1])
 
     @set_config(logging_modules=["logging", "my.logging"])
@@ -64,7 +64,7 @@ class TestLoggingModuleDetection(CheckerTestCase):
         )
         self.checker.visit_module(None)
         self.checker.visit_import(stmts[0])
-        with self.assertAddsMessages(Message("logging-not-lazy", node=stmts[1])):
+        with self.assertAddsMessages(Message("logging-not-lazy", node=stmts[1], args=("lazy %",))):
             self.checker.visit_call(stmts[1])
 
     def _assert_logging_format_no_messages(self, stmt):
@@ -140,42 +140,6 @@ class TestLoggingModuleDetection(CheckerTestCase):
     @pytest.mark.skipif(sys.version_info < (3, 6), reason="F-string require >=3.6")
     @set_config(logging_format_style="new")
     def test_fstr_not_new_format_style_matching_arguments(self):
-        msg = "logging-format-interpolation"
-        args = ("{", "")
+        msg = "logging-fstring-interpolation"
+        args = ("lazy %",)
         self._assert_logging_format_message(msg, "(f'{named}')", args)
-
-    @set_config(logging_format_style="fstr")
-    def test_modulo_not_fstr_format_style_matching_arguments(self):
-        msg = "logging-format-interpolation"
-        args = ("f-string", "")
-        with_too_many = False
-        self._assert_logging_format_message(msg, "('%s', 1)", args, with_too_many)
-        self._assert_logging_format_message(
-            msg, "('%(named)s', {'named': 1})", args, with_too_many
-        )
-        self._assert_logging_format_message(
-            msg, "('%s %(named)s', 1, {'named': 1})", args, with_too_many
-        )
-
-    @set_config(logging_format_style="fstr")
-    def test_brace_not_fstr_format_style_matching_arguments(self):
-        msg = "logging-format-interpolation"
-        args = ("f-string", "")
-        with_too_many = False
-        self._assert_logging_format_message(msg, "('{}', 1)", args, with_too_many)
-        self._assert_logging_format_message(msg, "('{0}', 1)", args, with_too_many)
-        self._assert_logging_format_message(
-            msg, "('{named}', {'named': 1})", args, with_too_many
-        )
-        self._assert_logging_format_message(
-            msg, "('{} {named}', 1, {'named': 1})", args, with_too_many
-        )
-        self._assert_logging_format_message(
-            msg, "('{0} {named}', 1, {'named': 1})", args, with_too_many
-        )
-
-    @pytest.mark.skipif(sys.version_info < (3, 6), reason="F-string require >=3.6")
-    @set_config(logging_format_style="fstr")
-    def test_fstr_format_style_matching_arguments(self):
-        self._assert_logging_format_no_messages("(f'constant string')")
-        self._assert_logging_format_no_messages("(f'{named}')")