diff --git a/tests/conftest.py b/tests/conftest.py
index 36f9eef..908eb69 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -1,53 +1,32 @@
 import pytest
+from src.models.data_structures import Author, Commit
 from datetime import datetime
-from unittest.mock import MagicMock, patch
 
 
 @pytest.fixture
-def mock_commit():
-    """Create a mock commit object."""
-    commit = MagicMock()
-    commit.sha = "abc123"
-    commit.message = "Test commit"
-    commit.author_name = "John Doe"
-    commit.author_email = "john@test.com"
-    commit.committed_datetime = datetime(2024, 1, 15, 10, 30, 0)
-    commit.author_datetime = datetime(2024, 1, 15, 10, 30, 0)
-    commit.additions = 50
-    commit.deletions = 10
-    commit.files_changed = ["src/main.py", "tests/test.py"]
-    commit.parents = []
-    commit.is_merge = False
-    commit.is_revert = False
-    commit.lines_changed_count = 60
-    return commit
+def sample_commit():
+    """Create a sample commit for testing."""
+    return Commit(
+        sha="abc123def456",
+        message="Add new feature",
+        author="Test User",
+        author_email="test@example.com",
+        timestamp=datetime(2024, 1, 15, 10, 30, 0),
+        lines_added=50,
+        lines_deleted=10,
+        files_changed=["src/new_feature.py"],
+        is_merge=False,
+        is_revert=False,
+    )
 
 
 @pytest.fixture
-def mock_repo():
-    """Create a mock git repository."""
-    repo = MagicMock()
-    return repo
-
-
-@pytest.fixture
-def sample_commits():
-    """Create a list of sample commits."""
-    commits = []
-    for i in range(10):
-        commit = MagicMock()
-        commit.sha = f"sha{i}"
-        commit.message = f"Commit {i}"
-        commit.author_name = "John Doe"
-        commit.author_email = "john@test.com"
-        commit.committed_datetime = datetime(2024, 1, i + 1, 10, 0, 0)
-        commit.author_datetime = datetime(2024, 1, i + 1, 10, 0, 0)
-        commit.additions = 10 * i
-        commit.deletions = 5 * i
-        commit.files_changed = [f"src/file{i}.py"]
-        commit.parents = []
-        commit.is_merge = False
-        commit.is_revert = False
-        commit.lines_changed_count = 15 * i
-        commits.append(commit)
-    return commits
+def sample_author():
+    """Create a sample author for testing."""
+    return Author(
+        name="Test User",
+        email="test@example.com",
+        commit_count=42,
+        lines_added=5000,
+        lines_deleted=1000,
+    )