increase test coverage

tests/test_docker_builder.py

@@ -11,6 +11,8 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+import pytest
+
 import litserve as ls
 from litserve import docker_builder
 
@@ -42,14 +44,19 @@ def test_color():
 def test_build(tmp_path, monkeypatch):
     with open(tmp_path / "app.py", "w") as f:
         f.write("print('hello')")
-    with open(tmp_path / "requirements.txt", "w") as f:
-        f.write("lightning")
 
     # Temporarily change the current working directory to tmp_path
     monkeypatch.chdir(tmp_path)
 
-    docker_builder.build("app.py", 8000)
+    with pytest.warns(UserWarning, match="Make sure to install the required packages in the Dockerfile."):
+        docker_builder.build("app.py", 8000)
 
+    with open(tmp_path / "requirements.txt", "w") as f:
+        f.write("lightning")
+    docker_builder.build("app.py", 8000)
     with open("Dockerfile") as f:
         content = f.read()
     assert content == EXPECTED_CONENT
+
+    with pytest.raises(FileNotFoundError, match="must be in the current directory"):
+        docker_builder.build("random_file_name.py", 8000)