feat: log errors to logfile, display to user

app/app_controller.py

@@ -20,6 +20,7 @@ def copy_files_from_source_to_destination(self):
         StatPresenter().present_analysis_of_candidate_files(self.source_directory, self.destination_directory)
         if self.__user_confirmation_of_copy():
             FileCopier().copy_source_files_to_destination()
+        self.__display_errors()
         FileGateway().wipe_database()  # TODO dev only, remove later
 
     def __create_db_records_for_files_to_be_copied(self, destination_directory):
@@ -32,3 +33,7 @@ def __user_confirmation_of_copy(self):
         print(f'Proceed with copy? ( y / n )')
         if input() == 'y':
             return True
+
+    def __display_errors(self):
+        error_messages = Logger().write_errors_to_logfile()
+        print(error_messages) if error_messages else None

app/db_controller.py

@@ -1,5 +1,8 @@
+import sqlite3
 from sqlite3 import Error
 
+from app.logger import Logger
+
 
 class DBControllerMeta(type):
     _instance = {}
@@ -25,8 +28,7 @@ def execute_query(self, query, values):
             cursor.execute(query, values)
             self.connection.commit()
         except Error as e:
-            print(f"Error '{e}' occurred with \nQuery {query}\nValues: {values}")
-            raise Error
+            Logger().log_error(e, values)
 
     def execute_read_query(self, query):
         cursor = self.connection.cursor()

app/logger.py

@@ -15,6 +15,8 @@ class Logger(metaclass=LoggerMeta):
 
     def __init__(self):
         self.log_file_path = None
+        self.error_messages = []
+        self.combined_error_messages = ''
 
     def init_log_file(self, destination_directory):
         timestamp = datetime.now().strftime('%Y-%m-%d-%H%M.%S')
@@ -35,6 +37,15 @@ def log_unsuccessful_copy(self, source_file_path, destination_filepath):
         log_entry = f'Copy failed:    {source_file_path} not copied to {destination_filepath}'
         self.__write_to_logfile(log_entry)
 
+    def log_error(self, error, values):
+        message = f'Error: {error}. Values: {values}'
+        self.error_messages.append(message)
+
+    def write_errors_to_logfile(self):
+        heading = '\nErrors:\n'
+        self.combined_error_messages = '\n'.join(self.error_messages)
+        self.__write_to_logfile(heading + self.combined_error_messages)
+
     def __write_to_logfile(self, log_entry):
         with open(self.log_file_path, 'a') as file:
             file.write(f'{log_entry}\n')

test/test_logger.py

@@ -42,3 +42,33 @@ def test_unsuccessful_write_to_logfile():
 
     expected_entry = f'Copy failed:    {source_file_path} not copied to {destination_filepath}\n'
     assert expected_entry == content
+
+
+def test_logs_error():
+    # reset error log as it may be populated by other tests
+    Logger().error_messages = []
+
+    values = ['/source/file1.jpg', '/destination/file1.jpg', 1024, None, False]
+    error = 'UNIQUE constraint failed: files.source_filepath'
+    expected_error_message = "Error: UNIQUE constraint failed: files.source_filepath. Values: " \
+                             "['/source/file1.jpg', '/destination/file1.jpg', 1024, None, False]"
+    Logger().log_error(error, values)
+    assert Logger().error_messages[0] == expected_error_message
+
+
+def test_writes_errors_to_logfile():
+    # reset error log as it may be populated by other tests
+    Logger().error_messages = []
+
+    values = ['/source/file1.jpg', '/destination/file1.jpg', 1024, None, False]
+    error = 'UNIQUE constraint failed: files.source_filepath'
+    Logger().log_error(error, values)
+    Logger().write_errors_to_logfile()
+
+    with open(Logger().log_file_path, 'r') as file:
+        content = file.read()
+
+    expected_content = "\nErrors:\nError: UNIQUE constraint failed: files.source_filepath. Values: " \
+                       "['/source/file1.jpg', '/destination/file1.jpg', 1024, None, False]\n"
+
+    assert expected_content == content