test: unit, integration and e2e tests

Task: MIL-002#6

tests/unit/conftest.py

@@ -0,0 +1,30 @@
+"""Shared fakes of the ports for the unit tests."""
+
+import pytest
+
+from password_manager.domain.errors import DataFileNotFoundError, EntryNotFoundError
+from password_manager.domain.password_entry import PasswordEntry
+
+
+class FakePasswordRepository:
+    """In-memory PasswordRepository; `has_file` False mimics a missing file."""
+
+    def __init__(self, has_file: bool = True) -> None:
+        self.entries: dict[str, PasswordEntry] = {}
+        self.has_file = has_file
+
+    def add(self, entry: PasswordEntry) -> None:
+        self.entries[entry.website] = entry
+        self.has_file = True
+
+    def find(self, website: str) -> PasswordEntry:
+        if not self.has_file:
+            raise DataFileNotFoundError
+        if website not in self.entries:
+            raise EntryNotFoundError(website)
+        return self.entries[website]
+
+
+@pytest.fixture
+def repository() -> FakePasswordRepository:
+    return FakePasswordRepository()