Capture python warnings and report them as matches

This change introduces a new way to generate warnings in linter, one
that uses the warnings support in Python. The benefit is that this
allows use to generate warnings from anywhere inside the code without
having to pass them from function to function.

For start we will be using this for internal rules, like ability to
report outdated noqa comments.

.github/workflows/tox.yml

@@ -59,7 +59,7 @@ jobs:
       WSLENV: FORCE_COLOR:PYTEST_REQPASS:TOXENV:GITHUB_STEP_SUMMARY
       # Number of expected test passes, safety measure for accidental skip of
       # tests. Update value if you add/remove tests.
-      PYTEST_REQPASS: 794
+      PYTEST_REQPASS: 795
     steps:
       - name: Activate WSL1
         if: "contains(matrix.shell, 'wsl')"

examples/playbooks/capture-warning.yml

@@ -0,0 +1,8 @@
+---
+- name: Fixture to generate a warning
+  hosts: localhost
+  tasks:
+    - name: Generate a warning
+      ansible.builtin.debug:
+        msg: "This is a warning"
+      when: "{{ false }}" # noqa: 102 jinja[spacing]

src/ansiblelint/errors.py

@@ -13,6 +13,20 @@
     from ansiblelint.utils import Task
 
 
+class LintWarning(Warning):
+    """Used by linter."""
+
+
+@dataclass
+class WarnSource:
+    """Container for warning information, so we can later create a MatchError from it."""
+
+    filename: Lintable
+    lineno: int
+    tag: str
+    message: str | None = None
+
+
 class StrictModeError(RuntimeError):
     """Raise when we encounter a warning in strict mode."""
 

src/ansiblelint/rules/__init__.py

@@ -119,7 +119,10 @@ def matchlines(self, file: Lintable) -> list[MatchError]:
             if line.lstrip().startswith("#"):
                 continue
 
-            rule_id_list = ansiblelint.skip_utils.get_rule_skips_from_line(line)
+            rule_id_list = ansiblelint.skip_utils.get_rule_skips_from_line(
+                line,
+                lintable=file,
+            )
             if self.id in rule_id_list:
                 continue
 

src/ansiblelint/rules/jinja.py

@@ -203,7 +203,10 @@ def matchyaml(self, file: Lintable) -> list[MatchError]:
                 lines = file.content.splitlines()
                 for match in raw_results:
                     # lineno starts with 1, not zero
-                    skip_list = get_rule_skips_from_line(lines[match.lineno - 1])
+                    skip_list = get_rule_skips_from_line(
+                        line=lines[match.lineno - 1],
+                        lintable=file,
+                    )
                     if match.rule.id not in skip_list and match.tag not in skip_list:
                         results.append(match)
         else:

src/ansiblelint/rules/var_naming.py

@@ -95,7 +95,10 @@ def matchplay(self, file: Lintable, data: dict[str, Any]) -> list[MatchError]:
             lines = file.content.splitlines()
             for match in raw_results:
                 # lineno starts with 1, not zero
-                skip_list = get_rule_skips_from_line(lines[match.lineno - 1])
+                skip_list = get_rule_skips_from_line(
+                    line=lines[match.lineno - 1],
+                    lintable=file,
+                )
                 if match.rule.id not in skip_list and match.tag not in skip_list:
                     results.append(match)
 
@@ -175,7 +178,10 @@ def matchyaml(self, file: Lintable) -> list[MatchError]:
                 lines = file.content.splitlines()
                 for match in raw_results:
                     # lineno starts with 1, not zero
-                    skip_list = get_rule_skips_from_line(lines[match.lineno - 1])
+                    skip_list = get_rule_skips_from_line(
+                        line=lines[match.lineno - 1],
+                        lintable=file,
+                    )
                     if match.rule.id not in skip_list and match.tag not in skip_list:
                         results.append(match)
         else:

src/ansiblelint/runner.py

@@ -5,15 +5,16 @@
 import multiprocessing
 import multiprocessing.pool
 import os
+import warnings
 from dataclasses import dataclass
 from fnmatch import fnmatch
 from typing import TYPE_CHECKING, Any
 
 import ansiblelint.skip_utils
 import ansiblelint.utils
-from ansiblelint._internal.rules import LoadingFailureRule
+from ansiblelint._internal.rules import LoadingFailureRule, WarningRule
 from ansiblelint.constants import States
-from ansiblelint.errors import MatchError
+from ansiblelint.errors import LintWarning, MatchError, WarnSource
 from ansiblelint.file_utils import Lintable, expand_dirs_in_lintables
 from ansiblelint.rules.syntax_check import AnsibleSyntaxCheckRule
 
@@ -112,8 +113,51 @@ def is_excluded(self, lintable: Lintable) -> bool:
             for path in self.exclude_paths
         )
 
-    def run(self) -> list[MatchError]:  # noqa: C901
+    def run(self) -> list[MatchError]:
         """Execute the linting process."""
+        matches: list[MatchError] = []
+        with warnings.catch_warnings(record=True) as captured_warnings:
+            warnings.simplefilter("always")
+            matches = self._run()
+            for warn in captured_warnings:
+                # For the moment we are ignoring deprecation warnings as Ansible
+                # modules outside current content can generate them and user
+                # might not be able to do anything about them.
+                if warn.category is DeprecationWarning:
+                    continue
+                if warn.category is LintWarning:
+                    filename: None | Lintable = None
+                    if isinstance(warn.source, WarnSource):
+                        match = MatchError(
+                            message=warn.source.message or warn.category.__name__,
+                            rule=WarningRule(),
+                            filename=warn.source.filename.filename,
+                            tag=warn.source.tag,
+                            lineno=warn.source.lineno,
+                        )
+                    else:
+                        filename = warn.source
+                        # breakpoint()
+                        match = MatchError(
+                            message=warn.message
+                            if isinstance(warn.message, str)
+                            else "?",
+                            rule=WarningRule(),
+                            filename=str(filename),
+                        )
+                    matches.append(match)
+                    continue
+                _logger.warning(
+                    "%s:%s %s %s",
+                    warn.filename,
+                    warn.lineno or 1,
+                    warn.category.__name__,
+                    warn.message,
+                )
+        return matches
+
+    def _run(self) -> list[MatchError]:  # noqa: C901
+        """Run the linting (inner loop)."""
         files: list[Lintable] = []
         matches: list[MatchError] = []
 

src/ansiblelint/skip_utils.py

@@ -24,6 +24,7 @@
 import collections.abc
 import logging
 import re
+import warnings
 from functools import cache
 from itertools import product
 from typing import TYPE_CHECKING, Any
@@ -41,6 +42,7 @@
     RENAMED_TAGS,
     SKIPPED_RULES_KEY,
 )
+from ansiblelint.errors import LintWarning, WarnSource
 
 if TYPE_CHECKING:
     from collections.abc import Generator, Sequence
@@ -60,7 +62,11 @@
 # ansible.parsing.yaml.objects.AnsibleSequence
 
 
-def get_rule_skips_from_line(line: str) -> list[str]:
+def get_rule_skips_from_line(
+    line: str,
+    lintable: Lintable,
+    lineno: int = 1,
+) -> list[str]:
     """Return list of rule ids skipped via comment on the line of yaml."""
     _before_noqa, _noqa_marker, noqa_text = line.partition("# noqa")
 
@@ -69,10 +75,17 @@ def get_rule_skips_from_line(line: str) -> list[str]:
         if v in RENAMED_TAGS:
             tag = RENAMED_TAGS[v]
             if v not in _found_deprecated_tags:
-                _logger.warning(
-                    "Replaced outdated tag '%s' with '%s', replace it to avoid future regressions",
-                    v,
-                    tag,
+                msg = f"Replaced outdated tag '{v}' with '{tag}', replace it to avoid future errors"
+                warnings.warn(
+                    message=msg,
+                    category=LintWarning,
+                    source=WarnSource(
+                        filename=lintable,
+                        lineno=lineno,
+                        tag="warning[outdated-tag]",
+                        message=msg,
+                    ),
+                    stacklevel=0,
                 )
                 _found_deprecated_tags.add(v)
             v = tag
@@ -257,7 +270,11 @@ def traverse_yaml(obj: Any) -> None:  # noqa: C901
                     if _noqa_comment_re.match(comment_str):
                         line = v.start_mark.line + 1  # ruamel line numbers start at 0
                         lintable.line_skips[line].update(
-                            get_rule_skips_from_line(comment_str.strip()),
+                            get_rule_skips_from_line(
+                                comment_str.strip(),
+                                lintable=lintable,
+                                lineno=line,
+                            ),
                         )
         yaml_comment_obj_strings.append(str(obj.ca.items))
         if isinstance(obj, dict):
@@ -277,7 +294,7 @@ def traverse_yaml(obj: Any) -> None:  # noqa: C901
     rule_id_list = []
     for comment_obj_str in yaml_comment_obj_strings:
         for line in comment_obj_str.split(r"\n"):
-            rule_id_list.extend(get_rule_skips_from_line(line))
+            rule_id_list.extend(get_rule_skips_from_line(line, lintable=lintable))
 
     return [normalize_tag(tag) for tag in rule_id_list]
 

test/test_skiputils.py

@@ -8,6 +8,7 @@
 
 from ansiblelint.constants import SKIPPED_RULES_KEY
 from ansiblelint.file_utils import Lintable
+from ansiblelint.runner import Runner
 from ansiblelint.skip_utils import (
     append_skipped_rules,
     get_rule_skips_from_line,
@@ -17,6 +18,7 @@
 if TYPE_CHECKING:
     from ansible.parsing.yaml.objects import AnsibleBaseYAMLObject
 
+    from ansiblelint.rules import RulesCollection
     from ansiblelint.testing import RunFromText
 
 PLAYBOOK_WITH_NOQA = """\
@@ -43,7 +45,7 @@
 )
 def test_get_rule_skips_from_line(line: str, expected: str) -> None:
     """Validate get_rule_skips_from_line."""
-    v = get_rule_skips_from_line(line)
+    v = get_rule_skips_from_line(line, lintable=Lintable(""))
     assert v == [expected]
 
 
@@ -232,3 +234,19 @@ def test_append_skipped_rules(
 def test_is_nested_task(task: dict[str, Any], expected: bool) -> None:
     """Test is_nested_task() returns expected bool."""
     assert is_nested_task(task) == expected
+
+
+def test_capture_warning_outdated_tag(
+    default_rules_collection: RulesCollection,
+) -> None:
+    """Test that exclude paths do work."""
+    runner = Runner(
+        "examples/playbooks/capture-warning.yml",
+        rules=default_rules_collection,
+    )
+
+    matches = runner.run()
+    assert len(matches) == 1
+    assert matches[0].rule.id == "warning"
+    assert matches[0].tag == "warning[outdated-tag]"
+    assert matches[0].lineno == 8