From c90a777557dff0a1bdadc65797dd4ac37b720f56 Mon Sep 17 00:00:00 2001
From: Erle Carrara <carrara.erle@gmail.com>
Date: Thu, 24 Apr 2025 21:45:48 -0300
Subject: [PATCH] Add support for ReviewDog JSON output format

Introduce a new command-line option '--rdjson' to format Cyclomatic
Complexity results for ReviewDog.
---
 radon/cli/__init__.py   |  9 ++++++++
 radon/cli/harvest.py    | 13 +++++++++++
 radon/cli/tools.py      | 50 +++++++++++++++++++++++++++++++++++++++++
 radon/tests/test_cli.py |  1 +
 4 files changed, 73 insertions(+)

diff --git a/radon/cli/__init__.py b/radon/cli/__init__.py
index 3af5138..e5681db 100644
--- a/radon/cli/__init__.py
+++ b/radon/cli/__init__.py
@@ -110,6 +110,7 @@ def cc(
     xml=False,
     md=False,
     codeclimate=False,
+    rdjson=False,
     output_file=_cfg.get_value('output_file', str, None),
     include_ipynb=_cfg.get_value('include_ipynb', bool, False),
     ipynb_cells=_cfg.get_value('ipynb_cells', bool, False),
@@ -142,6 +143,7 @@ def cc(
     :param --xml: Format results in XML (compatible with CCM).
     :param --md: Format results in Markdown.
     :param --codeclimate: Format results for Code Climate.
+    :param --rdjson: Format results for ReviewDog.
     :param --no-assert: Do not count `assert` statements when computing
         complexity.
     :param --show-closures: Add closures/inner classes to the output.
@@ -171,6 +173,7 @@ def cc(
             xml=xml,
             md=md,
             codeclimate=codeclimate,
+            rdjson=rdjson,
             stream=stream,
         )
 
@@ -380,6 +383,12 @@ def log_result(harvester, **kwargs):
             noformat=True,
             **kwargs
         )
+    elif kwargs.get('rdjson'):
+        log(
+            harvester.as_reviewdog_diagnostic_format(),
+            noformat=True,
+            **kwargs
+        )
     elif kwargs.get('md'):
         log(harvester.as_md(), noformat=True, **kwargs)
     else:
diff --git a/radon/cli/harvest.py b/radon/cli/harvest.py
index ac14fe5..32fd0c1 100644
--- a/radon/cli/harvest.py
+++ b/radon/cli/harvest.py
@@ -15,6 +15,7 @@
     dict_to_md,
     iter_filenames,
     raw_to_dict,
+    dict_to_reviewdog_diagnostic_format,
     strip_ipython,
 )
 from radon.complexity import (
@@ -163,6 +164,10 @@ def as_codeclimate_issues(self):
         '''Format the results as Code Climate issues.'''
         raise NotImplementedError
 
+    def as_reviewdog_diagnostic_format(self):
+        '''Format the results as ReviewDog Diagnostic Format (RDJSON).'''
+        raise NotImplementedError
+
     def to_terminal(self):
         '''Yields tuples representing lines to be printed to a terminal.
 
@@ -216,6 +221,14 @@ def as_codeclimate_issues(self):
         '''Format the result as Code Climate issues.'''
         return dict_to_codeclimate_issues(self._to_dicts(), self.config.min)
 
+    def as_reviewdog_diagnostic_format(self):
+        '''Formatthe result as Reviewdog Diagnostic Format
+
+        See https://github.com/reviewdog/reviewdog/tree/master/proto/rdf#rdjson
+        for more information about the format.
+        '''''
+        return dict_to_reviewdog_diagnostic_format(self._to_dicts(), self.config.min)
+
     def to_terminal(self):
         '''Yield lines to be printed in a terminal.'''
         average_cc = 0.0
diff --git a/radon/cli/tools.py b/radon/cli/tools.py
index cc8d4fa..c582519 100644
--- a/radon/cli/tools.py
+++ b/radon/cli/tools.py
@@ -446,6 +446,56 @@ def dict_to_codeclimate_issues(results, threshold='B'):
     return codeclimate_issues
 
 
+
+def dict_to_reviewdog_diagnostic_format(results, threshold='B'):
+    diagnostics = []
+
+    for path in results:
+        info = results[path]
+        for offender in info:
+            beginline = offender['lineno']
+            col_offset = offender['col_offset']
+            endline = offender['endline']
+            complexity = offender['complexity']
+            rank = offender['rank']
+            description = (
+                'Cyclomatic complexity is too high in {0} {1}. '
+                '({2})'.format(
+                    offender['type'], offender['name'], rank
+                )
+            )
+            remediation_points = get_remediation_points(
+                complexity, threshold
+            )
+
+            if remediation_points > 0:
+                diagnostics.append({
+                    "message": description,
+                    "location": {
+                        "path": path,
+                        "range": {
+                            "start": {
+                                "line": beginline,
+                                "column": col_offset
+                            },
+                            "end": {
+                                "line": endline,
+                                "column": None
+                            }
+                        }
+                    },
+                })
+
+    return json.dumps({
+        "source": {
+            "name": "radon cc",
+            "url": "https://radon.readthedocs.io/en/latest/commandline.html#the-cc-command"
+        },
+        "severity": "WARNING",
+        "diagnostics": diagnostics
+    })
+
+
 def cc_to_terminal(results, show_complexity, min, max, total_average):
     '''Transform Cyclomatic Complexity results into a 3-elements tuple:
 
diff --git a/radon/tests/test_cli.py b/radon/tests/test_cli.py
index 8b19372..e05fcc4 100644
--- a/radon/tests/test_cli.py
+++ b/radon/tests/test_cli.py
@@ -112,6 +112,7 @@ def test_cc(mocker, log_mock):
     log_mock.assert_called_once_with(
         mocker.sentinel.harvester,
         codeclimate=False,
+        rdjson=False,
         json=True,
         stream=sys.stdout,
         xml=False,