Adding command to generate swagger/openapi doc

Author: mlasevich

.idea/fastapi-cli.iml

@@ -0,0 +1,25 @@
+{
+  "openapi": "3.1.0",
+  "info": {
+    "title": "FastAPI",
+    "version": "0.1.0"
+  },
+  "paths": {
+    "/": {
+      "get": {
+        "summary": "App Root",
+        "operationId": "app_root__get",
+        "responses": {
+          "200": {
+            "description": "Successful Response",
+            "content": {
+              "application/json": {
+                "schema": {}
+              }
+            }
+          }
+        }
+      }
+    }
+  }
+}

.idea/inspectionProfiles/Project_Default.xml

@@ -1,3 +1,5 @@
+import json
+import sys
 from logging import getLogger
 from pathlib import Path
 from typing import Any, Union
@@ -9,6 +11,7 @@
 from typing_extensions import Annotated
 
 from fastapi_cli.discover import get_import_string
+from fastapi_cli.discover import get_app
 from fastapi_cli.exceptions import FastAPICLIException
 
 from . import __version__
@@ -272,6 +275,43 @@ def run(
         proxy_headers=proxy_headers,
     )
 
+@app.command()
+def schema(
+        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."
+            ),
+        ] = None,
+        *,
+        app: Annotated[
+            Union[str, None],
+            typer.Option(
+                help="The name of the variable that contains the [bold]FastAPI[/bold] app in the imported module or package. If not provided, it is detected automatically."
+            ),
+        ] = None,
+        output: Annotated[
+            Union[str, None],
+            typer.Option(
+                help="The filename to write schema to. If not provided, write to stderr."
+            ),
+        ] = None,
+        indent: Annotated[
+            int,
+            typer.Option(
+                help="JSON format indent. If 0, disable pretty printing"
+            ),
+        ] = 2,
+        ) -> Any:
+    """ Generate schema """
+    app = get_app(path=path, app_name=app)
+    schema = app.openapi()
+
+    stream = open(output, "w") if output else sys.stderr
+    json.dump(schema, stream, indent=indent if indent > 0 else None)
+    if output:
+        stream.close()
+    return 0
 
 def main() -> None:
     app()

.idea/misc.xml

@@ -1,5 +1,6 @@
 import importlib
 import sys
+from contextlib import contextmanager
 from dataclasses import dataclass
 from logging import getLogger
 from pathlib import Path
@@ -46,6 +47,18 @@ class ModuleData:
     module_import_str: str
     extra_sys_path: Path
 
+    @contextmanager
+    def sys_path(self):
+        """ Context manager to temporarily alter sys.path"""
+        extra_sys_path = str(self.extra_sys_path) if self.extra_sys_path else ""
+        if extra_sys_path:
+            logger.warning("Adding %s to sys.path...", extra_sys_path)
+            sys.path.insert(0, extra_sys_path)
+            yield
+        if extra_sys_path and sys.path and sys.path[0] == extra_sys_path:
+            logger.warning("Removing %s from sys.path...", extra_sys_path)
+            sys.path.pop(0)
+
 
 def get_module_data_from_path(path: Path) -> ModuleData:
     logger.info(
@@ -165,3 +178,54 @@ def get_import_string(
     import_string = f"{mod_data.module_import_str}:{use_app_name}"
     logger.info(f"Using import string [b green]{import_string}[/b green]")
     return import_string
+
+def get_app(
+        *, path: Union[Path, None] = None, app_name: Union[str, None] = None
+) -> FastAPI:
+    if not path:
+        path = get_default_path()
+    logger.debug(f"Using path [blue]{path}[/blue]")
+    logger.debug(f"Resolved absolute path {path.resolve()}")
+    if not path.exists():
+        raise FastAPICLIException(f"Path does not exist {path}")
+    mod_data = get_module_data_from_path(path)
+    try:
+        with mod_data.sys_path():
+            mod = importlib.import_module(mod_data.module_import_str)
+    except (ImportError, ValueError) as e:
+        logger.error(f"Import error: {e}")
+        logger.warning(
+            "Ensure all the package directories have an [blue]__init__.py["
+            "/blue] file"
+        )
+        raise
+    if not FastAPI:  # type: ignore[truthy-function]
+        raise FastAPICLIException(
+            "Could not import FastAPI, try running 'pip install fastapi'"
+        ) from None
+    object_names = dir(mod)
+    object_names_set = set(object_names)
+    if app_name:
+        if app_name not in object_names_set:
+            raise FastAPICLIException(
+                f"Could not find app name {app_name} in "
+                f"{mod_data.module_import_str}"
+            )
+        app = getattr(mod, app_name)
+        if not isinstance(app, FastAPI):
+            raise FastAPICLIException(
+                f"The app name {app_name} in {mod_data.module_import_str} "
+                f"doesn't seem to be a FastAPI app"
+            )
+        return app
+    for preferred_name in ["app", "api"]:
+        if preferred_name in object_names_set:
+            obj = getattr(mod, preferred_name)
+            if isinstance(obj, FastAPI):
+                return obj
+    for name in object_names:
+        obj = getattr(mod, name)
+        if isinstance(obj, FastAPI):
+            return obj
+    raise FastAPICLIException(
+        "Could not find FastAPI app in module, try using --app")

.idea/modules.xml

@@ -0,0 +1,25 @@
+{
+  "openapi": "3.1.0",
+  "info": {
+    "title": "FastAPI",
+    "version": "0.1.0"
+  },
+  "paths": {
+    "/": {
+      "get": {
+        "summary": "App Root",
+        "operationId": "app_root__get",
+        "responses": {
+          "200": {
+            "description": "Successful Response",
+            "content": {
+              "application/json": {
+                "schema": {}
+              }
+            }
+          }
+        }
+      }
+    }
+  }
+}

.idea/vcs.xml

@@ -179,6 +179,15 @@ def test_dev_help() -> None:
     assert "The name of the variable that contains the FastAPI app" in result.output
     assert "Use multiple worker processes." not in result.output
 
+def test_schema() -> None:
+    with changing_dir(assets_path):
+        with open('openapi.json', 'r') as stream:
+            expected = stream.read()
+        assert expected != "" , "Failed to read expected result"
+        result = runner.invoke(app, ["schema", "single_file_app.py"])
+        assert result.exit_code == 0, result.output
+        assert expected in result.output,  result.output
+
 
 def test_run_help() -> None:
     result = runner.invoke(app, ["run", "--help"])