feat: import plugin using import_module

Makefile

@@ -5,9 +5,18 @@ SOURCE_FILES=spectree tests examples setup.py
 install:
 	pip install -e .[email,flask,falcon,starlette,dev]
 
-test:
+import_test:
+	pip install -e .[email]
+	for module in flask falcon starlette; do \
+		pip install -U $$module; \
+		bash -c "python tests/import_module/test_$${module}_plugin.py" || exit 1; \
+		pip uninstall $$module -y; \
+	done
+
+test: import_test
 	pip install -U -e .[email,flask,falcon,starlette]
 	pytest tests -vv -rs
+
 doc:
 	cd docs && make html
 

spectree/plugins/__init__.py

@@ -1,12 +1,15 @@
+from collections import namedtuple
+
 from .base import BasePlugin
-from .falcon_plugin import FalconAsgiPlugin, FalconPlugin
-from .flask_plugin import FlaskPlugin
-from .starlette_plugin import StarlettePlugin
+
+__all__ = ["BasePlugin"]
+
+Plugin = namedtuple("Plugin", ("name", "package", "class_name"))
 
 PLUGINS = {
-    "base": BasePlugin,
-    "flask": FlaskPlugin,
-    "falcon": FalconPlugin,
-    "falcon-asgi": FalconAsgiPlugin,
-    "starlette": StarlettePlugin,
+    "base": Plugin(".base", __name__, "BasePlugin"),
+    "flask": Plugin(".flask_plugin", __name__, "FlaskPlugin"),
+    "falcon": Plugin(".falcon_plugin", __name__, "FalconPlugin"),
+    "falcon-asgi": Plugin(".falcon_plugin", __name__, "FalconAsgiPlugin"),
+    "starlette": Plugin(".starlette_plugin", __name__, "StarlettePlugin"),
 }

spectree/plugins/falcon_plugin.py

@@ -3,6 +3,8 @@
 from functools import partial
 from typing import Any, Callable, Dict, List, Mapping, Optional, get_type_hints
 
+from falcon import HTTP_400, HTTP_415, HTTPError
+from falcon.routing.compiled import _FIELD_PATTERN as FALCON_FIELD_PATTERN
 from pydantic import ValidationError
 
 from .._types import ModelType
@@ -51,12 +53,7 @@ class FalconPlugin(BasePlugin):
     def __init__(self, spectree):
         super().__init__(spectree)
 
-        from falcon import HTTP_400, HTTP_415, HTTPError
-        from falcon.routing.compiled import _FIELD_PATTERN
-
-        self.FALCON_HTTP_ERROR = HTTPError
         self.FALCON_MEDIA_ERROR_CODE = (HTTP_400, HTTP_415)
-        self.FIELD_PATTERN = _FIELD_PATTERN
         # NOTE from `falcon.routing.compiled.CompiledRouterNode`
         self.ESCAPE = r"[\.\(\)\[\]\?\$\*\+\^\|]"
         self.ESCAPE_TO = r"\\\g<0>"
@@ -109,13 +106,13 @@ def parse_func(self, route: Any) -> Dict[str, Any]:
     def parse_path(self, route, path_parameter_descriptions):
         subs, parameters = [], []
         for segment in route.uri_template.strip("/").split("/"):
-            matches = self.FIELD_PATTERN.finditer(segment)
+            matches = FALCON_FIELD_PATTERN.finditer(segment)
             if not matches:
                 subs.append(segment)
                 continue
 
             escaped = re.sub(self.ESCAPE, self.ESCAPE_TO, segment)
-            subs.append(self.FIELD_PATTERN.sub(self.EXTRACT, escaped))
+            subs.append(FALCON_FIELD_PATTERN.sub(self.EXTRACT, escaped))
 
             for field in matches:
                 variable, converter, argstr = [
@@ -180,7 +177,7 @@ def request_validation(self, req, query, json, form, headers, cookies):
         if json:
             try:
                 media = req.media
-            except self.FALCON_HTTP_ERROR as err:
+            except HTTPError as err:
                 if err.status not in self.FALCON_MEDIA_ERROR_CODE:
                     raise
                 media = None
@@ -268,15 +265,15 @@ async def request_validation(self, req, query, json, form, headers, cookies):
         if json:
             try:
                 media = await req.get_media()
-            except self.FALCON_HTTP_ERROR as err:
+            except HTTPError as err:
                 if err.status not in self.FALCON_MEDIA_ERROR_CODE:
                     raise
                 media = None
             req.context.json = json.parse_obj(media)
         if form:
             try:
                 form_data = await req.get_media()
-            except self.FALCON_HTTP_ERROR as err:
+            except HTTPError as err:
                 if err.status not in self.FALCON_MEDIA_ERROR_CODE:
                     raise
                 req.context.form = None

spectree/plugins/flask_plugin.py

@@ -1,6 +1,8 @@
 from typing import Any, Callable, Mapping, Optional, Tuple, get_type_hints
 
+from flask import Blueprint, abort, current_app, jsonify, make_response, request
 from pydantic import BaseModel, ValidationError
+from werkzeug.routing import parse_converter_args
 
 from .._types import ModelType
 from ..response import Response
@@ -12,8 +14,6 @@ class FlaskPlugin(BasePlugin):
     blueprint_state = None
 
     def find_routes(self):
-        from flask import current_app
-
         for rule in current_app.url_map.iter_rules():
             if any(
                 str(rule).startswith(path)
@@ -39,8 +39,6 @@ def bypass(self, func, method):
         return method in ["HEAD", "OPTIONS"]
 
     def parse_func(self, route: Any):
-        from flask import current_app
-
         if self.blueprint_state:
             func = self.blueprint_state.app.view_functions[route.endpoint]
         else:
@@ -62,8 +60,6 @@ def parse_path(
         route: Optional[Mapping[str, str]],
         path_parameter_descriptions: Optional[Mapping[str, str]],
     ) -> Tuple[str, list]:
-        from werkzeug.routing import parse_converter_args
-
         subs = []
         parameters = []
 
@@ -183,8 +179,6 @@ def validate(
         *args: Any,
         **kwargs: Any,
     ):
-        from flask import abort, jsonify, make_response, request
-
         response, req_validation_error, resp_validation_error = None, None, None
         try:
             self.request_validation(request, query, json, form, headers, cookies)
@@ -240,8 +234,6 @@ def validate(
         return response
 
     def register_route(self, app):
-        from flask import Blueprint, jsonify
-
         app.add_url_rule(
             rule=self.config.spec_url,
             endpoint=f"openapi_{self.config.path}",

spectree/plugins/starlette_plugin.py

@@ -5,6 +5,10 @@
 from typing import Any, Callable, Optional, get_type_hints
 
 from pydantic import ValidationError
+from starlette.convertors import CONVERTOR_TYPES
+from starlette.requests import Request
+from starlette.responses import HTMLResponse, JSONResponse
+from starlette.routing import compile_path
 
 from .._types import ModelType
 from ..response import Response
@@ -15,8 +19,6 @@
 
 
 def PydanticResponse(content):
-    from starlette.responses import JSONResponse
-
     class _PydanticResponse(JSONResponse):
         def render(self, content) -> bytes:
             self._model_class = content.__class__
@@ -30,13 +32,11 @@ class StarlettePlugin(BasePlugin):
 
     def __init__(self, spectree):
         super().__init__(spectree)
-        from starlette.convertors import CONVERTOR_TYPES
 
         self.conv2type = {conv: typ for typ, conv in CONVERTOR_TYPES.items()}
 
     def register_route(self, app):
         self.app = app
-        from starlette.responses import HTMLResponse, JSONResponse
 
         self.app.add_route(
             self.config.spec_url,
@@ -86,8 +86,6 @@ async def validate(
         *args: Any,
         **kwargs: Any,
     ):
-        from starlette.requests import Request
-        from starlette.responses import JSONResponse
 
         if isinstance(args[0], Request):
             instance, request = None, args[0]
@@ -193,7 +191,6 @@ def parse_func(self, route):
             yield method, route.func
 
     def parse_path(self, route, path_parameter_descriptions):
-        from starlette.routing import compile_path
 
         _, path, variables = compile_path(route.path)
         parameters = []

spectree/spec.py

@@ -1,6 +1,7 @@
 from collections import defaultdict
 from copy import deepcopy
 from functools import wraps
+from importlib import import_module
 from typing import (
     Any,
     Callable,
@@ -67,8 +68,12 @@ def __init__(
         self.validation_error_status = validation_error_status
         self.config: Configuration = Configuration.parse_obj(kwargs)
         self.backend_name = backend_name
-        self.backend = backend(self) if backend else PLUGINS[backend_name](self)
-        # init
+        if backend:
+            self.backend = backend(self)
+        else:
+            plugin = PLUGINS[backend_name]
+            module = import_module(plugin.name, plugin.package)
+            self.backend = getattr(module, plugin.class_name)(self)
         self.models: Dict[str, Any] = {}
         if app:
             self.register(app)

tests/import_module/test_falcon_plugin.py

@@ -0,0 +1,5 @@
+from spectree import SpecTree
+
+SpecTree("falcon")
+SpecTree("falcon-asgi")
+print("=> passed falcon plugin import test")

tests/import_module/test_flask_plugin.py

@@ -0,0 +1,4 @@
+from spectree import SpecTree
+
+SpecTree("flask")
+print("=> passed flask plugin import test")

tests/import_module/test_starlette_plugin.py

@@ -0,0 +1,4 @@
+from spectree import SpecTree
+
+SpecTree("starlette")
+print("=> passed starlette plugin import test")

tests/test_spec.py

@@ -7,7 +7,7 @@
 from spectree import Response
 from spectree.config import Configuration
 from spectree.models import Server, ValidationError
-from spectree.plugins import FlaskPlugin
+from spectree.plugins.flask_plugin import FlaskPlugin
 from spectree.spec import SpecTree
 
 from .common import get_paths