Add forgotten-debug-statement checker (#4771)

* Add ``no-breakpoint`` checker this adds a checker for calls to ``breakpoint()``, ``pdb.set_trace()``, or ``sys.breakpointhook()``.

Closes #3692

Co-authored-by: Marc Mueller <[email protected]>
Co-authored-by: Pierre Sassoulas <[email protected]>

Author: 3 people

ChangeLog

@@ -48,6 +48,10 @@ Release date: TBA
 
   * Extended ``consider-using-tuple`` check to cover ``in`` comparisons.
 
+* Added ``forgotten-debug-statement``: Emitted when ``breakpoint``, ``pdb.set_trace`` or ``sys.breakpointhook`` calls are found
+
+  Closes #3692
+
 
 What's New in Pylint 2.9.6?
 ===========================

doc/whatsnew/2.10.rst

@@ -24,6 +24,10 @@ New checkers
 
   Closes #4365
 
+* Added ``forgotten-debug-statement``: Emitted when ``breakpoint``, ``pdb.set_trace`` or ``sys.breakpointhook`` calls are found
+
+  Closes #3692
+
 
 Extensions
 ==========

pylint/checkers/stdlib.py

@@ -55,6 +55,7 @@
 SUBPROCESS_POPEN = "subprocess.Popen"
 SUBPROCESS_RUN = "subprocess.run"
 OPEN_MODULE = "_io"
+DEBUG_BREAKPOINTS = ("builtins.breakpoint", "sys.breakpointhook", "pdb.set_trace")
 
 
 DEPRECATED_MODULES = {
@@ -434,6 +435,12 @@ class StdlibChecker(DeprecatedMixin, BaseChecker):
             "Using the system default implicitly can create problems on other operating systems. "
             "See https://www.python.org/dev/peps/pep-0597/",
         ),
+        "W1515": (
+            "Leaving functions creating breakpoints in production code is not recommended",
+            "forgotten-debug-statement",
+            "Calls to breakpoint(), sys.breakpointhook() and pdb.set_trace() should be removed "
+            "from code that is not actively being debugged.",
+        ),
     }
 
     def __init__(self, linter=None):
@@ -495,6 +502,7 @@ def _check_shallow_copy_environ(self, node):
         "subprocess-run-check",
         "deprecated-class",
         "unspecified-encoding",
+        "forgotten-debug-statement",
     )
     def visit_call(self, node):
         """Visit a Call node."""
@@ -531,6 +539,8 @@ def visit_call(self, node):
                         self._check_env_function(node, inferred)
                     elif name == SUBPROCESS_RUN:
                         self._check_for_check_kw_in_run(node)
+                    elif name in DEBUG_BREAKPOINTS:
+                        self.add_message("forgotten-debug-statement", node=node)
                 self.check_deprecated_method(node, inferred)
         except astroid.InferenceError:
             return

tests/functional/f/forgotten_debug_statement_py37.py

@@ -0,0 +1,10 @@
+# pylint: disable=missing-docstring
+
+import pdb
+import sys
+
+breakpoint()  # [forgotten-debug-statement]
+sys.breakpointhook()  # [forgotten-debug-statement]
+pdb.set_trace()  # [forgotten-debug-statement]
+b = breakpoint
+b()  # [forgotten-debug-statement]

tests/functional/f/forgotten_debug_statement_py37.rc

@@ -0,0 +1,2 @@
+[testoptions]
+min_pyver=3.7

tests/functional/f/forgotten_debug_statement_py37.txt

@@ -0,0 +1,4 @@
+forgotten-debug-statement:6:0::"Leaving functions creating breakpoints in production code is not recommended"
+forgotten-debug-statement:7:0::"Leaving functions creating breakpoints in production code is not recommended"
+forgotten-debug-statement:8:0::"Leaving functions creating breakpoints in production code is not recommended"
+forgotten-debug-statement:10:0::"Leaving functions creating breakpoints in production code is not recommended"