Added integration with eradicate to highlight dead code

There's an awesome Python project called `eradicate` (https://github.com/PyCQA/eradicate), but it doesn't seem to have a PyLint plugin. This PR adds this integration.

.github/workflows/push.yml

@@ -43,6 +43,8 @@ jobs:
 
       - name: Publish test coverage
         uses: codecov/codecov-action@v4
+        with:
+          token: ${{ secrets.CODECOV_TOKEN }}
 
   fmt:
     runs-on: ubuntu-latest

NOTICE

@@ -2,6 +2,12 @@ Copyright (2024) Databricks, Inc.
 
 This Software includes software developed at Databricks (https://www.databricks.com/) and its use is subject to the included LICENSE file.
 
+This Software contains code from the following open source projects, licensed under the MIT license:
+
+Eradicate - https://github.com/PyCQA/eradicate
+Copyright (C) 2012-2018 Steven Myint
+License - https://github.com/PyCQA/eradicate/blob/master/eradicate.py#L1-L20
+
 This Software contains code from the following open source projects, licensed under the Apache 2.0 license:
 
 Databricks SDK for Python - https://github.com/databricks/databricks-sdk-py

README.md

@@ -43,6 +43,8 @@ PyLint with checks for common mistakes and issues in Python code specifically in
   * [`mocking` checker](#mocking-checker)
     * [`R8918`: `explicit-dependency-required`](#r8918-explicit-dependency-required)
     * [`R8919`: `obscure-mock`](#r8919-obscure-mock)
+  * [`eradicate` checker](#eradicate-checker)
+    * [`C8920`: `dead-code`](#c8920-dead-code)
   * [Testing in isolation](#testing-in-isolation)
 * [Project Support](#project-support)
 <!-- TOC -->
@@ -335,11 +337,24 @@ To disable this check on a specific line, add `# pylint: disable=obscure-mock` a
 
 [[back to top](#pylint-plugin-for-databricks)]
 
+## `eradicate` checker
+To use this checker, add `databricks.labs.pylint.eradicate` to `load-plugins` configuration in your `pylintrc` or `pyproject.toml` file.
+
+[[back to top](#pylint-plugin-for-databricks)]
+
+### `C8920`: `dead-code`
+
+Remove commented out code: XXX. Version control helps with keeping track of code changes. There is no need to keep commented out code in the codebase. Remove it to keep the codebase clean.
+
+To disable this check on a specific line, add `# pylint: disable=dead-code` at the end of it.
+
+[[back to top](#pylint-plugin-for-databricks)]
+
 ## Testing in isolation
 To test this plugin in isolation, you can use the following command:
 
 ```bash
-pylint --load-plugins=databricks.labs.pylint.all --disable=all --enable=missing-data-security-mode,unsupported-runtime,dbutils-fs-cp,dbutils-fs-head,dbutils-fs-ls,dbutils-fs-mount,dbutils-credentials,dbutils-notebook-run,pat-token-leaked,internal-api,legacy-cli,incompatible-with-uc,notebooks-too-many-cells,notebooks-percent-run,spark-outside-function,use-display-instead-of-show,no-spark-argument-in-function,explicit-dependency-required,obscure-mock .
+pylint --load-plugins=databricks.labs.pylint.all --disable=all --enable=missing-data-security-mode,unsupported-runtime,dbutils-fs-cp,dbutils-fs-head,dbutils-fs-ls,dbutils-fs-mount,dbutils-credentials,dbutils-notebook-run,pat-token-leaked,internal-api,legacy-cli,incompatible-with-uc,notebooks-too-many-cells,notebooks-percent-run,spark-outside-function,use-display-instead-of-show,no-spark-argument-in-function,explicit-dependency-required,obscure-mock,dead-code .
 ```
 
 [[back to top](#pylint-plugin-for-databricks)]

pyproject.toml

@@ -20,7 +20,12 @@ classifiers = [
     "Programming Language :: Python :: 3.12",
     "Programming Language :: Python :: Implementation :: CPython",
 ]
-dependencies = ["pylint", "astroid", "databricks-sdk"]
+dependencies = [
+    "pylint",
+    "astroid",
+    "databricks-sdk",
+    "eradicate~=2.3.0",
+]
 
 [project.urls]
 Issues = "https://github.com/databrickslabs/pylint-plugin/issues"

scripts/docs.py

@@ -5,6 +5,7 @@
 
 from databricks.labs.pylint.airflow import AirflowChecker
 from databricks.labs.pylint.dbutils import DbutilsChecker
+from databricks.labs.pylint.eradicate import EradicateChecker
 from databricks.labs.pylint.legacy import LegacyChecker
 from databricks.labs.pylint.mocking import MockingChecker
 from databricks.labs.pylint.notebooks import NotebookChecker
@@ -23,6 +24,7 @@ def do_something():
         NotebookChecker(linter),
         SparkChecker(linter),
         MockingChecker(linter),
+        EradicateChecker(linter),
     ]:
         out.append(f"## `{checker.name}` checker")
         out.append(

src/databricks/labs/pylint/all.py

@@ -1,5 +1,6 @@
 from databricks.labs.pylint.airflow import AirflowChecker
 from databricks.labs.pylint.dbutils import DbutilsChecker
+from databricks.labs.pylint.eradicate import EradicateChecker
 from databricks.labs.pylint.legacy import LegacyChecker
 from databricks.labs.pylint.mocking import MockingChecker
 from databricks.labs.pylint.notebooks import NotebookChecker
@@ -13,3 +14,4 @@ def register(linter):
     linter.register_checker(AirflowChecker(linter))
     linter.register_checker(SparkChecker(linter))
     linter.register_checker(MockingChecker(linter))
+    linter.register_checker(EradicateChecker(linter))

src/databricks/labs/pylint/eradicate.py

@@ -0,0 +1,32 @@
+import astroid
+from eradicate import Eradicator
+from pylint.checkers import BaseRawFileChecker
+from pylint.interfaces import HIGH
+
+
+class EradicateChecker(BaseRawFileChecker):
+    name = "eradicate"
+
+    msgs = {
+        "C8920": (
+            "Remove commented out code: %s",
+            "dead-code",
+            "Version control helps with keeping track of code changes. There is no need to keep commented out code in "
+            "the codebase. Remove it to keep the codebase clean.",
+        ),
+    }
+
+    def open(self) -> None:
+        self._eradicator = Eradicator()
+
+    def process_module(self, node: astroid.Module):
+        with node.stream() as stream:
+            source = stream.read().decode()
+            lines = source.splitlines()
+            for line_no in self._eradicator.commented_out_code_line_numbers(source):
+                src_line = lines[line_no - 1].strip()
+                self.add_message("dead-code", line=line_no, confidence=HIGH, args=(src_line,))
+
+
+def register(linter):
+    linter.register_checker(EradicateChecker(linter))

tests/samples/d/dead_code.py

@@ -0,0 +1,5 @@
+# pylint: disable=missing-module-docstring
+print("Hello, world!")
+# +1: [dead-code]
+# print('Goodbye, world!')
+print("...")

tests/samples/d/dead_code.txt

@@ -0,0 +1 @@
+dead-code:4:0:None:None::"Remove commented out code: # print('Goodbye, world!')":HIGH

tests/samples/m/many_cells.py

@@ -1,5 +1,5 @@
 # Databricks notebook source
-# pylint: disable=missing-module-docstring
+# pylint: disable=missing-module-docstring,dead-code
 
 print("Hello, World!")