Adding factory argument

src/fastapi_cli/cli.py

@@ -60,9 +60,12 @@ def _run(
     command: str,
     app: Union[str, None] = None,
     proxy_headers: bool = False,
+    is_factory: bool = False,
 ) -> None:
     try:
-        use_uvicorn_app = get_import_string(path=path, app_name=app)
+        use_uvicorn_app = get_import_string(
+            path=path, app_name=app, is_factory=is_factory
+        )
     except FastAPICLIException as e:
         logger.error(str(e))
         raise typer.Exit(code=1) from None
@@ -97,6 +100,7 @@ def _run(
         workers=workers,
         root_path=root_path,
         proxy_headers=proxy_headers,
+        factory=is_factory,
     )
 
 
@@ -105,7 +109,7 @@ def dev(
     path: Annotated[
         Union[Path, None],
         typer.Argument(
-            help="A path to a Python file or package directory (with [blue]__init__.py[/blue] files) containing a [bold]FastAPI[/bold] app. If not provided, a default set of paths will be tried."
+            help="A path to a Python file or package directory (with [blue]__init__.py[/blue] files) containing a [bold]FastAPI[/bold] app or app factory. If not provided, a default set of paths will be tried."
         ),
     ] = None,
     *,
@@ -145,6 +149,12 @@ def dev(
             help="Enable/Disable X-Forwarded-Proto, X-Forwarded-For, X-Forwarded-Port to populate remote address info."
         ),
     ] = True,
+    factory: Annotated[
+        bool,
+        typer.Option(
+            help="Treat [bold]path[/bold] as an application factory, i.e. a () -> <ASGI app> callable."
+        ),
+    ] = False,
 ) -> Any:
     """
     Run a [bold]FastAPI[/bold] app in [yellow]development[/yellow] mode. 🧪
@@ -180,6 +190,7 @@ def dev(
         app=app,
         command="dev",
         proxy_headers=proxy_headers,
+        is_factory=factory,
     )
 
 
@@ -234,6 +245,12 @@ def run(
             help="Enable/Disable X-Forwarded-Proto, X-Forwarded-For, X-Forwarded-Port to populate remote address info."
         ),
     ] = True,
+    factory: Annotated[
+        bool,
+        typer.Option(
+            help="Treat [bold]path[/bold] as an application factory, i.e. a () -> <ASGI app> callable."
+        ),
+    ] = False,
 ) -> Any:
     """
     Run a [bold]FastAPI[/bold] app in [green]production[/green] mode. 🚀
@@ -270,6 +287,7 @@ def run(
         app=app,
         command="run",
         proxy_headers=proxy_headers,
+        is_factory=factory,
     )
 
 

src/fastapi_cli/discover.py

@@ -98,7 +98,9 @@ def get_module_data_from_path(path: Path) -> ModuleData:
     )
 
 
-def get_app_name(*, mod_data: ModuleData, app_name: Union[str, None] = None) -> str:
+def get_app_name(
+    *, mod_data: ModuleData, app_name: Union[str, None] = None, is_factory: bool = False
+) -> str:
     try:
         mod = importlib.import_module(mod_data.module_import_str)
     except (ImportError, ValueError) as e:
@@ -119,25 +121,37 @@ def get_app_name(*, mod_data: ModuleData, app_name: Union[str, None] = None) ->
                 f"Could not find app name {app_name} in {mod_data.module_import_str}"
             )
         app = getattr(mod, app_name)
-        if not isinstance(app, FastAPI):
+        if not isinstance(app, FastAPI) and not is_factory:
             raise FastAPICLIException(
                 f"The app name {app_name} in {mod_data.module_import_str} doesn't seem to be a FastAPI app"
             )
+        else:
+            if not callable(app) and is_factory:
+                raise FastAPICLIException(
+                    f"The app factory {app_name} in {mod_data.module_import_str} doesn't seem to be a function"
+                )
         return app_name
     for preferred_name in ["app", "api"]:
         if preferred_name in object_names_set:
             obj = getattr(mod, preferred_name)
-            if isinstance(obj, FastAPI):
+            if isinstance(obj, FastAPI) and not is_factory:
                 return preferred_name
     for name in object_names:
         obj = getattr(mod, name)
-        if isinstance(obj, FastAPI):
+        if isinstance(obj, FastAPI) and not is_factory:
+            return name
+        elif callable(name) and is_factory:
             return name
-    raise FastAPICLIException("Could not find FastAPI app in module, try using --app")
+    raise FastAPICLIException(
+        "Could not find FastAPI app or app factory in module, try using --app"
+    )
 
 
 def get_import_string(
-    *, path: Union[Path, None] = None, app_name: Union[str, None] = None
+    *,
+    path: Union[Path, None] = None,
+    app_name: Union[str, None] = None,
+    is_factory: bool = False,
 ) -> str:
     if not path:
         path = get_default_path()
@@ -147,7 +161,9 @@ def get_import_string(
         raise FastAPICLIException(f"Path does not exist {path}")
     mod_data = get_module_data_from_path(path)
     sys.path.insert(0, str(mod_data.extra_sys_path))
-    use_app_name = get_app_name(mod_data=mod_data, app_name=app_name)
+    use_app_name = get_app_name(
+        mod_data=mod_data, app_name=app_name, is_factory=is_factory
+    )
     import_example = Syntax(
         f"from {mod_data.module_import_str} import {use_app_name}", "python"
     )

tests/test_cli.py

@@ -29,6 +29,7 @@ def test_dev() -> None:
                 "workers": None,
                 "root_path": "",
                 "proxy_headers": True,
+                "factory": False,
             }
         assert "Using import string single_file_app:app" in result.output
         assert (
@@ -71,6 +72,7 @@ def test_dev_args() -> None:
                 "workers": None,
                 "root_path": "/api",
                 "proxy_headers": False,
+                "factory": False,
             }
         assert "Using import string single_file_app:api" in result.output
         assert (
@@ -97,6 +99,7 @@ def test_run() -> None:
                 "workers": None,
                 "root_path": "",
                 "proxy_headers": True,
+                "factory": False,
             }
         assert "Using import string single_file_app:app" in result.output
         assert (
@@ -141,6 +144,7 @@ def test_run_args() -> None:
                 "workers": 2,
                 "root_path": "/api",
                 "proxy_headers": False,
+                "factory": False,
             }
         assert "Using import string single_file_app:api" in result.output
         assert (

tests/test_utils_package.py

@@ -432,7 +432,8 @@ def test_package_dir_no_app() -> None:
         with pytest.raises(FastAPICLIException) as e:
             get_import_string(path=Path("package/core/utils.py"))
         assert (
-            "Could not find FastAPI app in module, try using --app" in e.value.args[0]
+            "Could not find FastAPI app or app factory in module, try using --app"
+            in e.value.args[0]
         )