[tracker-miners/sam/test-fixes: 5/8] Add TRACKER_DEBUG=tests-no-cleanup

[Sam Thursfield <sthursfield src gnome org>]

commit b551a75fc26729743d38eecfe39da3898aeb94d0
Author: Sam Thursfield <sam afuera me uk>
Date:   Fri May 1 21:40:15 2020 +0200

    Add TRACKER_DEBUG=tests-no-cleanup
    
    This causes the functional tests to save the data directory.
    Something I constantly finding myself modifying the source code
    to do when debugging them.

 tests/functional-tests/configuration.py | 46 ++++++++++++++++++++++++++-------
 1 file changed, 37 insertions(+), 9 deletions(-)
---
diff --git a/tests/functional-tests/configuration.py b/tests/functional-tests/configuration.py
index b8b955f77..3f3d96c0e 100644
--- a/tests/functional-tests/configuration.py
+++ b/tests/functional-tests/configuration.py
@@ -19,6 +19,8 @@
 #
 
 
+from gi.repository import GLib
+
 import errno
 import json
 import logging
@@ -83,16 +85,19 @@ def create_monitored_test_dir():
 
 
 def remove_monitored_test_dir(path):
-    shutil.rmtree(path)
+    if tests_no_cleanup():
+        print("\nTRACKER_DEBUG=tests-no-cleanup: Test data kept in %s" % path)
+    else:
+        shutil.rmtree(path)
 
-    # We delete the parent directory if possible, to avoid cluttering the user's
-    # home dir, but there may be other tests running in parallel so we ignore
-    # an error if there are still files present in it.
-    try:
-        os.rmdir(_TEST_MONITORED_TMP_DIR)
-    except OSError as e:
-        if e.errno == errno.ENOTEMPTY:
-            pass
+        # We delete the parent directory if possible, to avoid cluttering the user's
+        # home dir, but there may be other tests running in parallel so we ignore
+        # an error if there are still files present in it.
+        try:
+            os.rmdir(_TEST_MONITORED_TMP_DIR)
+        except OSError as e:
+            if e.errno == errno.ENOTEMPTY:
+                pass
 
 
 def get_environment_boolean(variable):
@@ -117,3 +122,26 @@ def get_environment_int(variable, default=0):
 
 def tests_verbose():
     return get_environment_boolean('TRACKER_TESTS_VERBOSE')
+
+
+DEBUG_TESTS_NO_CLEANUP = 1
+
+_debug_flags = None
+def get_debug_flags():
+    """Parse the TRACKER_DEBUG environment variable and return flags."""
+    global _debug_flags
+    if _debug_flags is None:
+        flag_tests_no_cleanup = GLib.DebugKey()
+        flag_tests_no_cleanup.key = 'tests-no-cleanup'
+        flag_tests_no_cleanup.value = DEBUG_TESTS_NO_CLEANUP
+
+        flags = [flag_tests_no_cleanup]
+        flags_str = os.environ.get('TRACKER_DEBUG', '')
+
+        _debug_flags = GLib.parse_debug_string(flags_str, flags)
+    return _debug_flags
+
+
+def tests_no_cleanup():
+    """True if TRACKER_DEBUG=tests-no-cleanup"""
+    return(get_debug_flags() & DEBUG_TESTS_NO_CLEANUP)