use decoupled but minimal git env in tests

When running in bare CI environments, the git tool is usually not
configured yet. By that, common operations like 'git commit' cannot be
executed in our tests. However, when running in local environments, the
git configuration might vary, making it hard to write robust test code.

This patch enhances our default test fixture to always prepare a stable,
minimal and decoupled environment. By that, tests that use git can be
written without needing the git setup boilerplate code.

Signed-off-by: Felix Moessbauer <[email protected]>
Signed-off-by: Jan Kiszka <[email protected]>

tests/conftest.py

@@ -21,6 +21,7 @@
 # SOFTWARE.
 
 import pytest
+import os
 
 ENVVARS_KAS = [
     'KAS_WORK_DIR',
@@ -36,14 +37,28 @@
     'SSH_AUTH_SOCK',
 ]
 
+ENVVARS_TOOLS = [
+    'EMAIL'
+]
+
 
 @pytest.fixture
 def monkeykas(monkeypatch, tmpdir):
-    for var in ENVVARS_KAS:
+    for var in ENVVARS_KAS + ENVVARS_TOOLS:
         monkeypatch.delenv(var, raising=False)
     # Set HOME to a temporary directory
     homedir = tmpdir / '_home'
     homedir.mkdir()
     monkeypatch.setenv('HOME', str(homedir))
 
+    # remove all git related variables
+    for var in os.environ.keys():
+        if var.startswith('GIT_'):
+            monkeypatch.delenv(var)
+    # provide minimal git environment
+    monkeypatch.setenv('GIT_AUTHOR_NAME', 'kas')
+    monkeypatch.setenv('GIT_AUTHOR_EMAIL', '[email protected]')
+    monkeypatch.setenv('GIT_COMMITTER_NAME', 'kas')
+    monkeypatch.setenv('GIT_COMMITTER_EMAIL', '[email protected]')
+
     yield monkeypatch