added tests for 'chat.py'

chatmastermind/chat.py

@@ -5,9 +5,10 @@ import shutil
 import pathlib
 from pprint import PrettyPrinter
 from pydoc import pager
-from dataclasses import dataclass, field
+from dataclasses import dataclass
-from typing import TypeVar, Type, Optional, ClassVar, Any
+from typing import TypeVar, Type, Optional, ClassVar, Any, Callable
-from .message import Question, Answer, Message, MessageFilter, MessageError, source_code
+from .message import Question, Answer, Message, MessageFilter, MessageError, source_code, message_in
+from .tags import Tag
 
 ChatInst = TypeVar('ChatInst', bound='Chat')
 ChatDBInst = TypeVar('ChatDBInst', bound='ChatDB')
@@ -29,6 +30,58 @@ def print_paged(text: str) -> None:
     pager(text)
 
 
+def read_dir(dir_path: pathlib.Path,
+             glob: Optional[str] = None,
+             mfilter: Optional[MessageFilter] = None) -> list[Message]:
+    """
+    Reads the messages from the given folder.
+    Parameters:
+    * 'dir_path': source directory
+    * 'glob': if specified, files will be filtered using 'path.glob()',
+      otherwise it uses 'path.iterdir()'.
+    * 'mfilter': use with 'Message.from_file()' to filter messages
+      when reading them.
+    """
+    messages: list[Message] = []
+    file_iter = dir_path.glob(glob) if glob else dir_path.iterdir()
+    for file_path in sorted(file_iter):
+        if file_path.is_file():
+            try:
+                message = Message.from_file(file_path, mfilter)
+                if message:
+                    messages.append(message)
+            except MessageError as e:
+                print(f"Error processing message in '{file_path}': {str(e)}")
+    return messages
+
+
+def write_dir(dir_path: pathlib.Path,
+              messages: list[Message],
+              file_suffix: str,
+              next_fid: Callable[[], int]) -> None:
+    """
+    Write all messages to the given directory. If a message has no file_path,
+    a new one will be created. If message.file_path exists, it will be modified
+    to point to the given directory.
+    Parameters:
+    * 'dir_path': destination directory
+    * 'messages': list of messages to write
+    * 'file_suffix': suffix for the message files ['.txt'|'.yaml']
+    * 'next_fid': callable that returns the next file ID
+    """
+    for message in messages:
+        file_path = message.file_path
+        # message has no file_path: create one
+        if not file_path:
+            fid = next_fid()
+            fname = f"{fid:04d}{file_suffix}"
+            file_path = dir_path / fname
+        # file_path does not point to given directory: modify it
+        elif not file_path.parent.samefile(dir_path):
+            file_path = dir_path / file_path.name
+        message.to_file(file_path)
+
+
 @dataclass
 class Chat:
     """
@@ -67,6 +120,15 @@ class Chat:
         self.messages += msgs
         self.sort()
 
+    def tags(self, prefix: Optional[str] = None, contain: Optional[str] = None) -> set[Tag]:
+        """
+        Get the tags of all messages, optionally filtered by prefix or substring.
+        """
+        tags: set[Tag] = set()
+        for m in self.messages:
+            tags |= m.filter_tags(prefix, contain)
+        return tags
+
     def print(self, dump: bool = False, source_code_only: bool = False,
               with_tags: bool = False, with_file: bool = False,
               paged: bool = True) -> None:
@@ -113,8 +175,10 @@ class ChatDB(Chat):
     file_suffix: str = default_file_suffix
     # the glob pattern for all messages
     glob: Optional[str] = None
-    # set containing all file names of the current messages
+
-    message_files: set[str] = field(default_factory=set, repr=False)
+    def __post_init__(self) -> None:
+        # contains the latest message ID
+        self.next_fname = self.db_path / '.next'
 
     @classmethod
     def from_dir(cls: Type[ChatDBInst],
@@ -128,94 +192,78 @@ class ChatDB(Chat):
         Parameters:
         * 'cache_path': path to the directory for temporary messages
         * 'db_path': path to the directory for persistent messages
-        * 'glob' fs specified, files will be filtered using 'path.glob()',
+        * 'glob': if specified, files will be filtered using 'path.glob()',
           otherwise it uses 'path.iterdir()'.
         * 'mfilter': use with 'Message.from_file()' to filter messages
           when reading them.
         """
-        messages: list[Message] = []
+        messages = read_dir(db_path, glob, mfilter)
-        message_files: set[str] = set()
-        file_iter = db_path.glob(glob) if glob else db_path.iterdir()
-        for file_path in sorted(file_iter):
-            if file_path.is_file():
-                try:
-                    message = Message.from_file(file_path, mfilter)
-                    if message:
-                        messages.append(message)
-                        message_files.add(file_path.name)
-                except MessageError as e:
-                    print(f"Error processing message in '{file_path}': {str(e)}")
         return cls(messages, cache_path, db_path, mfilter,
-                   cls.default_file_suffix, glob, message_files)
+                   cls.default_file_suffix, glob)
 
     @classmethod
     def from_messages(cls: Type[ChatDBInst],
                       cache_path: pathlib.Path,
                       db_path: pathlib.Path,
                       messages: list[Message],
-                      mfilter: Optional[MessageFilter]) -> ChatDBInst:
+                      mfilter: Optional[MessageFilter] = None) -> ChatDBInst:
         """
-        Create a ChatDB instance from the given message list. Note that the next
+        Create a ChatDB instance from the given message list.
-        call to 'dump()' will write all files in order to synchronize the messages.
-        Similarly, 'update()' will read all messages, so you may end up with a lot
-        of duplicates when using 'update()' first.
         """
         return cls(messages, cache_path, db_path, mfilter)
 
     def get_next_fid(self) -> int:
-        next_fname = self.db_path / '.next'
         try:
-            with open(next_fname, 'r') as f:
+            with open(self.next_fname, 'r') as f:
-                return int(f.read()) + 1
+                next_fid = int(f.read()) + 1
+            self.set_next_fid(next_fid)
+            return next_fid
         except Exception:
+            self.set_next_fid(1)
             return 1
 
     def set_next_fid(self, fid: int) -> None:
-        next_fname = self.db_path / '.next'
+        with open(self.next_fname, 'w') as f:
-        with open(next_fname, 'w') as f:
             f.write(f'{fid}')
 
-    def dump(self, to_db: bool = False, force_all: bool = False) -> None:
+    def read_db(self) -> None:
         """
-        Write all messages to 'cache_path' (or 'db_path' if 'to_db' is True). If a message
+        Reads new messages from the DB directory. New ones are added to the internal list,
-        has no file_path, a new one will be created. By default, only messages that have
+        existing ones are kept or replaced. A message is determined as 'existing' if a
-        not been written (or read) before will be dumped. Use 'force_all' to force writing
+        message with the same base filename (i. e. 'file_path.name') is already in the list.
-        all message files.
         """
-        for message in self.messages:
+        new_messages = read_dir(self.db_path, self.glob, self.mfilter)
-            # skip messages that we have already written (or read)
+        # remove all messages from self.messages that are in the new list
-            if message.file_path and message.file_path in self.message_files and not force_all:
+        self.messages = [m for m in self.messages if not message_in(m, new_messages)]
-                continue
+        # copy the messages from the temporary list to self.messages and sort them
-            file_path = message.file_path
+        self.messages += new_messages
-            if not file_path:
+        self.sort()
-                fid = self.get_next_fid()
-                fname = f"{fid:04d}{self.file_suffix}"
-                file_path = self.db_path / fname if to_db else self.cache_path / fname
-                self.set_next_fid(fid)
-            message.to_file(file_path)
 
-    def update(self, from_cache: bool = False, force_all: bool = False) -> None:
+    def read_cache(self) -> None:
         """
-        Read new messages from 'db_path' (or 'cache_path' if 'from_cache' is true).
+        Reads new messages from the cache directory. New ones are added to the internal list,
-        By default, only messages that have not been read (or written) before will
+        existing ones are kept or replaced. A message is determined as 'existing' if a
-        be read. Use 'force_all' to force reading all messages (existing messages
+        message with the same base filename (i. e. 'file_path.name') is already in the list.
-        are discarded).
         """
-        if from_cache:
+        new_messages = read_dir(self.db_path, self.glob, self.mfilter)
-            file_iter = self.cache_path.glob(self.glob) if self.glob else self.cache_path.iterdir()
+        # remove all messages from self.messages that are in the new list
-        else:
+        self.messages = [m for m in self.messages if not message_in(m, new_messages)]
-            file_iter = self.cache_path.glob(self.glob) if self.glob else self.cache_path.iterdir()
+        # copy the messages from the temporary list to self.messages and sort them
-        if force_all:
+        self.messages += new_messages
-            self.messages = []
+        self.sort()
-        for file_path in sorted(file_iter):
+
-            if file_path.is_file():
+    def write_db(self) -> None:
-                if file_path.name in self.message_files and not force_all:
+        """
-                    continue
+        Write all messages to the DB directory. If a message has no file_path,
-                try:
+        a new one will be created. If message.file_path exists, it will be modified
-                    message = Message.from_file(file_path, self.mfilter)
+        to point to the DB directory.
-                    if message:
+        """
-                        self.messages.append(message)
+        write_dir(self.db_path, self.messages, self.file_suffix, self.get_next_fid)
-                        self.message_files.add(file_path.name)
+
-                except MessageError as e:
+    def write_cache(self) -> None:
-                    print(f"Error processing message in '{file_path}': {str(e)}")
+        """
-            self.sort()
+        Write all messages to the cache directory. If a message has no file_path,
+        a new one will be created. If message.file_path exists, it will be modified
+        to point to the cache directory.
+        """
+        write_dir(self.cache_path, self.messages, self.file_suffix, self.get_next_fid)

chatmastermind/message.py

@@ -3,7 +3,7 @@ Module implementing message related functions and classes.
 """
 import pathlib
 import yaml
-from typing import Type, TypeVar, ClassVar, Optional, Any, Union, Final, Literal
+from typing import Type, TypeVar, ClassVar, Optional, Any, Union, Final, Literal, Iterable
 from dataclasses import dataclass, asdict, field
 from .tags import Tag, TagLine, TagError, match_tags
 
@@ -57,6 +57,20 @@ def source_code(text: str, include_delims: bool = False) -> list[str]:
     return code_sections
 
 
+def message_in(message: MessageInst, messages: Iterable[MessageInst]) -> bool:
+    """
+    Searches the given message list for a message with the same file
+    name as the given one (i. e. it compares Message.file_path.name).
+    If the given message has no file_path, False is returned.
+    """
+    if not message.file_path:
+        return False
+    for m in messages:
+        if m.file_path and m.file_path.name == message.file_path.name:
+            return True
+    return False
+
+
 @dataclass(kw_only=True)
 class MessageFilter:
     """
@@ -436,13 +450,14 @@ class Message():
         Filter tags based on their prefix (i. e. the tag starts with a given string)
         or some contained string.
         """
-        res_tags = self.tags
+        if not self.tags:
-        if res_tags:
+            return set()
-            if prefix and len(prefix) > 0:
+        res_tags = self.tags.copy()
-                res_tags -= {tag for tag in res_tags if not tag.startswith(prefix)}
+        if prefix and len(prefix) > 0:
-            if contain and len(contain) > 0:
+            res_tags -= {tag for tag in res_tags if not tag.startswith(prefix)}
-                res_tags -= {tag for tag in res_tags if contain not in tag}
+        if contain and len(contain) > 0:
-        return res_tags or set()
+            res_tags -= {tag for tag in res_tags if contain not in tag}
+        return res_tags
 
     def tags_str(self, prefix: Optional[str] = None, contain: Optional[str] = None) -> str:
         """

tests/test_chat.py

@@ -1,9 +1,11 @@
 import pathlib
+import tempfile
+import time
 from io import StringIO
 from unittest.mock import patch
 from chatmastermind.tags import TagLine
 from chatmastermind.message import Message, Question, Answer, Tag, MessageFilter
-from chatmastermind.chat import Chat, terminal_width
+from chatmastermind.chat import Chat, ChatDB, terminal_width
 from .test_main import CmmTestCase
 
 
@@ -12,11 +14,11 @@ class TestChat(CmmTestCase):
         self.chat = Chat([])
         self.message1 = Message(Question('Question 1'),
                                 Answer('Answer 1'),
-                                {Tag('tag1')},
+                                {Tag('atag1')},
                                 file_path=pathlib.Path('0001.txt'))
         self.message2 = Message(Question('Question 2'),
                                 Answer('Answer 2'),
-                                {Tag('tag2')},
+                                {Tag('btag2')},
                                 file_path=pathlib.Path('0002.txt'))
 
     def test_filter(self) -> None:
@@ -42,11 +44,19 @@ class TestChat(CmmTestCase):
 
     def test_add_msgs(self) -> None:
         self.chat.add_msgs([self.message1, self.message2])
-
         self.assertEqual(len(self.chat.messages), 2)
         self.assertEqual(self.chat.messages[0].question, 'Question 1')
         self.assertEqual(self.chat.messages[1].question, 'Question 2')
 
+    def test_tags(self) -> None:
+        self.chat.add_msgs([self.message1, self.message2])
+        tags_all = self.chat.tags()
+        self.assertSetEqual(tags_all, {Tag('atag1'), Tag('btag2')})
+        tags_pref = self.chat.tags(prefix='a')
+        self.assertSetEqual(tags_pref, {Tag('atag1')})
+        tags_cont = self.chat.tags(contain='2')
+        self.assertSetEqual(tags_cont, {Tag('btag2')})
+
     @patch('sys.stdout', new_callable=StringIO)
     def test_print(self, mock_stdout: StringIO) -> None:
         self.chat.add_msgs([self.message1, self.message2])
@@ -73,14 +83,152 @@ Answer 2
 Question 1
 {Answer.txt_header}
 Answer 1
-{TagLine.prefix} tag1
+{TagLine.prefix} atag1
 FILE: 0001.txt
 {'-'*terminal_width()}
 {Question.txt_header}
 Question 2
 {Answer.txt_header}
 Answer 2
-{TagLine.prefix} tag2
+{TagLine.prefix} btag2
 FILE: 0002.txt
 """
         self.assertEqual(mock_stdout.getvalue(), expected_output)
+
+
+class TestChatDB(CmmTestCase):
+    def setUp(self) -> None:
+        self.db_path = tempfile.TemporaryDirectory()
+        self.cache_path = tempfile.TemporaryDirectory()
+
+        self.message1 = Message(Question('Question 1'),
+                                Answer('Answer 1'),
+                                {Tag('tag1')},
+                                file_path=pathlib.Path('0001.txt'))
+        self.message2 = Message(Question('Question 2'),
+                                Answer('Answer 2'),
+                                {Tag('tag2')},
+                                file_path=pathlib.Path('0002.yaml'))
+        self.message3 = Message(Question('Question 3'),
+                                Answer('Answer 3'),
+                                {Tag('tag3')},
+                                file_path=pathlib.Path('0003.txt'))
+        self.message4 = Message(Question('Question 4'),
+                                Answer('Answer 4'),
+                                {Tag('tag4')},
+                                file_path=pathlib.Path('0004.yaml'))
+
+        self.message1.to_file(pathlib.Path(self.db_path.name, '0001.txt'))
+        self.message2.to_file(pathlib.Path(self.db_path.name, '0002.yaml'))
+        self.message3.to_file(pathlib.Path(self.db_path.name, '0003.txt'))
+        self.message4.to_file(pathlib.Path(self.db_path.name, '0004.yaml'))
+
+    def tearDown(self) -> None:
+        self.db_path.cleanup()
+        self.cache_path.cleanup()
+        pass
+
+    def test_chat_db_from_dir(self) -> None:
+        chat_db = ChatDB.from_dir(pathlib.Path(self.cache_path.name),
+                                  pathlib.Path(self.db_path.name))
+        self.assertEqual(len(chat_db.messages), 4)
+        self.assertEqual(chat_db.cache_path, pathlib.Path(self.cache_path.name))
+        self.assertEqual(chat_db.db_path, pathlib.Path(self.db_path.name))
+        # check that the files are sorted
+        self.assertEqual(chat_db.messages[0].file_path,
+                         pathlib.Path(self.db_path.name, '0001.txt'))
+        self.assertEqual(chat_db.messages[1].file_path,
+                         pathlib.Path(self.db_path.name, '0002.yaml'))
+        self.assertEqual(chat_db.messages[2].file_path,
+                         pathlib.Path(self.db_path.name, '0003.txt'))
+        self.assertEqual(chat_db.messages[3].file_path,
+                         pathlib.Path(self.db_path.name, '0004.yaml'))
+
+    def test_chat_db_from_dir_glob(self) -> None:
+        chat_db = ChatDB.from_dir(pathlib.Path(self.cache_path.name),
+                                  pathlib.Path(self.db_path.name),
+                                  glob='*.txt')
+        self.assertEqual(len(chat_db.messages), 2)
+        self.assertEqual(chat_db.cache_path, pathlib.Path(self.cache_path.name))
+        self.assertEqual(chat_db.db_path, pathlib.Path(self.db_path.name))
+        self.assertEqual(chat_db.messages[0].file_path,
+                         pathlib.Path(self.db_path.name, '0001.txt'))
+        self.assertEqual(chat_db.messages[1].file_path,
+                         pathlib.Path(self.db_path.name, '0003.txt'))
+
+    def test_chat_db_filter(self) -> None:
+        chat_db = ChatDB.from_dir(pathlib.Path(self.cache_path.name),
+                                  pathlib.Path(self.db_path.name),
+                                  mfilter=MessageFilter(answer_contains='Answer 2'))
+        self.assertEqual(len(chat_db.messages), 1)
+        self.assertEqual(chat_db.cache_path, pathlib.Path(self.cache_path.name))
+        self.assertEqual(chat_db.db_path, pathlib.Path(self.db_path.name))
+        self.assertEqual(chat_db.messages[0].file_path,
+                         pathlib.Path(self.db_path.name, '0002.yaml'))
+        self.assertEqual(chat_db.messages[0].answer, 'Answer 2')
+
+    def test_chat_db_from_messges(self) -> None:
+        chat_db = ChatDB.from_messages(pathlib.Path(self.cache_path.name),
+                                       pathlib.Path(self.db_path.name),
+                                       messages=[self.message1, self.message2,
+                                                 self.message3, self.message4])
+        self.assertEqual(len(chat_db.messages), 4)
+        self.assertEqual(chat_db.cache_path, pathlib.Path(self.cache_path.name))
+        self.assertEqual(chat_db.db_path, pathlib.Path(self.db_path.name))
+
+    def test_chat_db_fids(self) -> None:
+        chat_db = ChatDB.from_dir(pathlib.Path(self.cache_path.name),
+                                  pathlib.Path(self.db_path.name))
+        self.assertEqual(chat_db.get_next_fid(), 1)
+        self.assertEqual(chat_db.get_next_fid(), 2)
+        self.assertEqual(chat_db.get_next_fid(), 3)
+        with open(chat_db.next_fname, 'r') as f:
+            self.assertEqual(f.read(), '3')
+
+    def test_chat_db_write(self) -> None:
+        # create a new ChatDB instance
+        chat_db = ChatDB.from_dir(pathlib.Path(self.cache_path.name),
+                                  pathlib.Path(self.db_path.name))
+        # check that Message.file_path is correct
+        self.assertEqual(chat_db.messages[0].file_path, pathlib.Path(self.db_path.name, '0001.txt'))
+        self.assertEqual(chat_db.messages[1].file_path, pathlib.Path(self.db_path.name, '0002.yaml'))
+        self.assertEqual(chat_db.messages[2].file_path, pathlib.Path(self.db_path.name, '0003.txt'))
+        self.assertEqual(chat_db.messages[3].file_path, pathlib.Path(self.db_path.name, '0004.yaml'))
+
+        # write the messages to the cache directory
+        chat_db.write_cache()
+        # check if the written files are in the cache directory
+        cache_dir_files = list(pathlib.Path(self.cache_path.name).glob('*'))
+        self.assertEqual(len(cache_dir_files), 4)
+        self.assertIn(pathlib.Path(self.cache_path.name, '0001.txt'), cache_dir_files)
+        self.assertIn(pathlib.Path(self.cache_path.name, '0002.yaml'), cache_dir_files)
+        self.assertIn(pathlib.Path(self.cache_path.name, '0003.txt'), cache_dir_files)
+        self.assertIn(pathlib.Path(self.cache_path.name, '0004.yaml'), cache_dir_files)
+        # check that Message.file_path has been correctly updated
+        self.assertEqual(chat_db.messages[0].file_path, pathlib.Path(self.cache_path.name, '0001.txt'))
+        self.assertEqual(chat_db.messages[1].file_path, pathlib.Path(self.cache_path.name, '0002.yaml'))
+        self.assertEqual(chat_db.messages[2].file_path, pathlib.Path(self.cache_path.name, '0003.txt'))
+        self.assertEqual(chat_db.messages[3].file_path, pathlib.Path(self.cache_path.name, '0004.yaml'))
+
+        # check the timestamp of the files in the DB directory
+        db_dir_files = list(pathlib.Path(self.db_path.name).glob('*'))
+        self.assertEqual(len(db_dir_files), 4)
+        old_timestamps = {file: file.stat().st_mtime for file in db_dir_files}
+        # overwrite the messages in the db directory
+        time.sleep(0.05)
+        chat_db.write_db()
+        # check if the written files are in the DB directory
+        db_dir_files = list(pathlib.Path(self.db_path.name).glob('*'))
+        self.assertEqual(len(db_dir_files), 4)
+        self.assertIn(pathlib.Path(self.db_path.name, '0001.txt'), db_dir_files)
+        self.assertIn(pathlib.Path(self.db_path.name, '0002.yaml'), db_dir_files)
+        self.assertIn(pathlib.Path(self.db_path.name, '0003.txt'), db_dir_files)
+        self.assertIn(pathlib.Path(self.db_path.name, '0004.yaml'), db_dir_files)
+        # check if all files in the DB dir have actually been overwritten
+        for file in db_dir_files:
+            self.assertGreater(file.stat().st_mtime, old_timestamps[file])
+        # check that Message.file_path has been correctly updated (again)
+        self.assertEqual(chat_db.messages[0].file_path, pathlib.Path(self.db_path.name, '0001.txt'))
+        self.assertEqual(chat_db.messages[1].file_path, pathlib.Path(self.db_path.name, '0002.yaml'))
+        self.assertEqual(chat_db.messages[2].file_path, pathlib.Path(self.db_path.name, '0003.txt'))
+        self.assertEqual(chat_db.messages[3].file_path, pathlib.Path(self.db_path.name, '0004.yaml'))

tests/test_message.py

@@ -2,7 +2,7 @@ import pathlib
 import tempfile
 from typing import cast
 from .test_main import CmmTestCase
-from chatmastermind.message import source_code, Message, MessageError, Question, Answer, AILine, ModelLine, MessageFilter
+from chatmastermind.message import source_code, Message, MessageError, Question, Answer, AILine, ModelLine, MessageFilter, message_in
 from chatmastermind.tags import Tag, TagLine
 
 
@@ -594,6 +594,12 @@ This is an answer.
         self.file_path_txt.unlink()
         self.file_yaml.close()
         self.file_path_yaml.unlink()
+        self.file_txt_no_tags.close
+        self.file_path_txt_no_tags.unlink()
+        self.file_txt_tags_empty.close
+        self.file_path_txt_tags_empty.unlink()
+        self.file_yaml_no_tags.close()
+        self.file_path_yaml_no_tags.unlink()
 
     def test_tags_from_file_txt(self) -> None:
         tags = Message.tags_from_file(self.file_path_txt)
@@ -671,6 +677,7 @@ class TagsFromDirTestCase(CmmTestCase):
 
     def tearDown(self) -> None:
         self.temp_dir.cleanup()
+        self.temp_dir_no_tags.cleanup()
 
     def test_tags_from_dir(self) -> None:
         all_tags = Message.tags_from_dir(pathlib.Path(self.temp_dir.name))
@@ -739,3 +746,32 @@ class MessageTagsStrTestCase(CmmTestCase):
 
     def test_tags_str(self) -> None:
         self.assertEqual(self.message.tags_str(), f'{TagLine.prefix} tag1')
+
+
+class MessageFilterTagsTestCase(CmmTestCase):
+    def setUp(self) -> None:
+        self.message = Message(Question('This is a question.'),
+                               tags={Tag('atag1'), Tag('btag2')},
+                               file_path=pathlib.Path('/tmp/foo/bla'))
+
+    def test_filter_tags(self) -> None:
+        tags_all = self.message.filter_tags()
+        self.assertSetEqual(tags_all, {Tag('atag1'), Tag('btag2')})
+        tags_pref = self.message.filter_tags(prefix='a')
+        self.assertSetEqual(tags_pref, {Tag('atag1')})
+        tags_cont = self.message.filter_tags(contain='2')
+        self.assertSetEqual(tags_cont, {Tag('btag2')})
+
+
+class MessageInTestCase(CmmTestCase):
+    def setUp(self) -> None:
+        self.message1 = Message(Question('This is a question.'),
+                                tags={Tag('atag1'), Tag('btag2')},
+                                file_path=pathlib.Path('/tmp/foo/bla'))
+        self.message2 = Message(Question('This is a question.'),
+                                tags={Tag('atag1'), Tag('btag2')},
+                                file_path=pathlib.Path('/tmp/bla/foo'))
+
+    def test_message_in(self) -> None:
+        self.assertTrue(message_in(self.message1, [self.message1]))
+        self.assertFalse(message_in(self.message1, [self.message2]))