tests: clean up repo_trace._TRACE_FILE patching

Patch this automatically for all tests rather than duplicating the
boilerplate in diff testcases.

Change-Id: I391d5c859974cda3d5680d34ede2ce6e9e925838
Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/354358
Reviewed-by: Joanna Wang <jojwang@google.com>
Tested-by: Mike Frysinger <vapier@google.com>

run_tests

@@ -20,7 +20,6 @@ import os
 import shutil
 import subprocess
 import sys
-import repo_trace
 
 
 def find_pytest():

tests/conftest.py

@@ -0,0 +1,25 @@
+# Copyright 2022 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Common fixtures for pytests."""
+
+import pytest
+
+import repo_trace
+
+
+@pytest.fixture(autouse=True)
+def disable_repo_trace(tmp_path):
+  """Set an environment marker to relax certain strict checks for test code."""
+  repo_trace._TRACE_FILE = str(tmp_path / 'TRACE_FILE_from_test')

tests/test_git_config.py

@@ -19,7 +19,6 @@ import tempfile
 import unittest
 
 import git_config
-import repo_trace
 
 
 def fixture(*paths):
@@ -34,16 +33,9 @@ class GitConfigReadOnlyTests(unittest.TestCase):
   def setUp(self):
     """Create a GitConfig object using the test.gitconfig fixture.
     """
-
-    self.tempdirobj = tempfile.TemporaryDirectory(prefix='repo_tests')
-    repo_trace._TRACE_FILE = os.path.join(self.tempdirobj.name, 'TRACE_FILE_from_test')
-
     config_fixture = fixture('test.gitconfig')
     self.config = git_config.GitConfig(config_fixture)
 
-  def tearDown(self):
-    self.tempdirobj.cleanup()
-
   def test_GetString_with_empty_config_values(self):
     """
     Test config entries with no value.
@@ -117,15 +109,9 @@ class GitConfigReadWriteTests(unittest.TestCase):
   """Read/write tests of the GitConfig class."""
 
   def setUp(self):
-    self.tempdirobj = tempfile.TemporaryDirectory(prefix='repo_tests')
-    repo_trace._TRACE_FILE = os.path.join(self.tempdirobj.name, 'TRACE_FILE_from_test')
-
     self.tmpfile = tempfile.NamedTemporaryFile()
     self.config = self.get_config()
 
-  def tearDown(self):
-    self.tempdirobj.cleanup()
-
   def get_config(self):
     """Get a new GitConfig instance."""
     return git_config.GitConfig(self.tmpfile.name)

tests/test_git_superproject.py

@@ -24,7 +24,6 @@ from unittest import mock
 import git_superproject
 import git_trace2_event_log
 import manifest_xml
-import repo_trace
 from test_manifest_xml import sort_attributes
 
 
@@ -40,7 +39,6 @@ class SuperprojectTestCase(unittest.TestCase):
     """Set up superproject every time."""
     self.tempdirobj = tempfile.TemporaryDirectory(prefix='repo_tests')
     self.tempdir = self.tempdirobj.name
-    repo_trace._TRACE_FILE = os.path.join(self.tempdir, 'TRACE_FILE_from_test')
     self.repodir = os.path.join(self.tempdir, '.repo')
     self.manifest_file = os.path.join(
         self.repodir, manifest_xml.MANIFEST_FILE_NAME)

tests/test_manifest_xml.py

@@ -23,7 +23,6 @@ import xml.dom.minidom
 
 import error
 import manifest_xml
-import repo_trace
 
 
 # Invalid paths that we don't want in the filesystem.
@@ -94,7 +93,6 @@ class ManifestParseTestCase(unittest.TestCase):
   def setUp(self):
     self.tempdirobj = tempfile.TemporaryDirectory(prefix='repo_tests')
     self.tempdir = self.tempdirobj.name
-    repo_trace._TRACE_FILE = os.path.join(self.tempdir, 'TRACE_FILE_from_test')
     self.repodir = os.path.join(self.tempdir, '.repo')
     self.manifest_dir = os.path.join(self.repodir, 'manifests')
     self.manifest_file = os.path.join(

tests/test_project.py

@@ -27,7 +27,6 @@ import git_command
 import git_config
 import platform_utils
 import project
-import repo_trace
 
 
 @contextlib.contextmanager
@@ -66,13 +65,6 @@ class FakeProject(object):
 class ReviewableBranchTests(unittest.TestCase):
   """Check ReviewableBranch behavior."""
 
-  def setUp(self):
-    self.tempdirobj = tempfile.TemporaryDirectory(prefix='repo_tests')
-    repo_trace._TRACE_FILE = os.path.join(self.tempdirobj.name, 'TRACE_FILE_from_test')
-
-  def tearDown(self):
-    self.tempdirobj.cleanup()
-
   def test_smoke(self):
     """A quick run through everything."""
     with TempGitTree() as tempdir:
@@ -418,8 +410,6 @@ class ManifestPropertiesFetchedCorrectly(unittest.TestCase):
   """Ensure properties are fetched properly."""
 
   def setUpManifest(self, tempdir):
-    repo_trace._TRACE_FILE = os.path.join(tempdir, 'TRACE_FILE_from_test')
-
     repodir = os.path.join(tempdir, '.repo')
     manifest_dir = os.path.join(repodir, 'manifests')
     manifest_file = os.path.join(