chore(ci_visibility): don't log exception when codeowners can't be lo…

…aded (#10423)

Reverts the `Codeowners.__init__()` behavior introduced in #10094 which
changed the exception being caught by the `CIVisibility` service when
instantiating `Codeowners()`, resulting in undesirable log messages.

`Codeowners.__init__()` raising a `ValueError` exception, caught by the
sole caller (`CIVisibility.__init__()`).

The `of()` behavior is maintained and the caller is updated to check for
`[]` as an indication that no codeowner was found.

There is no release note as #10094 was only backported into `2.12`.

As a bonus, type hints are converted from comments to annotations.

## Checklist
- [x] PR author has checked that all the criteria below are met
- The PR description includes an overview of the change
- The PR description articulates the motivation for the change
- The change includes tests OR the PR description describes a testing
strategy
- The PR description notes risks associated with the change, if any
- Newly-added code is easy to change
- The change follows the [library release note
guidelines](https://ddtrace.readthedocs.io/en/stable/releasenotes.html)
- The change includes or references documentation updates if necessary
- Backport labels are set (if
[applicable](https://ddtrace.readthedocs.io/en/latest/contributing.html#backporting))

## Reviewer Checklist
- [ ] Reviewer has checked that all the criteria below are met 
- Title is accurate
- All changes are related to the pull request's stated goal
- Avoids breaking
[API](https://ddtrace.readthedocs.io/en/stable/versioning.html#interfaces)
changes
- Testing strategy adequately addresses listed risks
- Newly-added code is easy to change
- Release note makes sense to a user of the library
- If necessary, author has acknowledged and discussed the performance
implications of this PR as reported in the benchmarks PR comment
- Backport labels are set in a manner that is consistent with the
[release branch maintenance
policy](https://ddtrace.readthedocs.io/en/latest/contributing.html#backporting)

ddtrace/internal/ci_visibility/recorder.py

@@ -683,8 +683,10 @@ def set_codeowners_of(cls, location, span=None):
             handles = cls._instance._codeowners.of(location)
             if handles:
                 span.set_tag(test.CODEOWNERS, json.dumps(handles))
-        except KeyError:
-            log.debug("no matching codeowners for %s", location)
+            else:
+                log.debug("no matching codeowners for %s", location)
+        except:  # noqa: E722
+            log.debug("Error setting codeowners for %s", location, exc_info=True)
 
     @classmethod
     def add_session(cls, session: CIVisibilitySession):

ddtrace/internal/codeowners.py

@@ -1,12 +1,11 @@
 import os
 import re
-from typing import List  # noqa:F401
-from typing import Optional  # noqa:F401
-from typing import Tuple  # noqa:F401
+from typing import List
+from typing import Optional
+from typing import Tuple
 
 
-def path_to_regex(pattern):
-    # type: (str) -> re.Pattern
+def path_to_regex(pattern: str) -> re.Pattern:
     """
     source https://github.com/sbdchd/codeowners/blob/c95e13d384ac09cfa1c23be1a8601987f41968ea/codeowners/__init__.py
 
@@ -119,16 +118,20 @@ class Codeowners(object):
         ".gitlab/CODEOWNERS",
     )
 
-    def __init__(self, path=None, cwd=None):
-        # type: (Optional[str], Optional[str]) -> None
+    def __init__(self, path: Optional[str] = None, cwd: Optional[str] = None):
         """Initialize Codeowners object.
 
         :param path: path to CODEOWNERS file otherwise try to use any from known locations
         """
+        self.patterns: List[Tuple[re.Pattern, List[str]]] = []
+        self.path: Optional[str] = None
+
         path = path or self.location(cwd)
-        if path is not None:
-            self.path = path  # type: str
-        self.patterns = []  # type: List[Tuple[re.Pattern, List[str]]]
+
+        if path is None:
+            raise ValueError("CODEOWNERS file not found")
+
+        self.path = path
         self.parse()
 
     def location(self, cwd: Optional[str] = None) -> Optional[str]:
@@ -140,9 +143,11 @@ def location(self, cwd: Optional[str] = None) -> Optional[str]:
                 return path
         return None
 
-    def parse(self):
-        # type: () -> None
+    def parse(self) -> None:
         """Parse CODEOWNERS file and store the lines and regexes."""
+        if self.path is None:
+            return
+
         with open(self.path) as f:
             patterns = []
             for line in f.readlines():