Added test for functional based middleware

Author: eadwinCode

tests/test_application/test_functional_middleware.py

@@ -0,0 +1,69 @@
+from starlette.requests import Request
+from starlette.responses import PlainTextResponse
+
+from ellar.common import Module, ModuleRouter, middleware
+from ellar.core import TestClientFactory
+from ellar.core.context import IExecutionContext
+
+mr = ModuleRouter()
+
+
+@mr.get()
+def homepage(request: Request):
+    if request.headers.get("modified_header"):
+        return "homepage modified_header"
+
+    if request.state.user:
+        return request.state.user
+    return "homepage"
+
+
+@Module(routers=[mr])
+class ModuleMiddleware:
+    @middleware()
+    async def middleware_modify_response(cls, context: IExecutionContext, call_next):
+        response = context.get_response()
+        response.headers.setdefault("modified-header", "Ellar")
+        await call_next()
+
+    @middleware()
+    async def middleware_modify_request(cls, context: IExecutionContext, call_next):
+        request = context.switch_to_request()
+        request.state.user = None
+        if request.headers.get("set-user"):
+            request.state.user = dict(username="Ellar")
+        await call_next()
+
+    @middleware()
+    async def middleware_return_response(cls, context: IExecutionContext, call_next):
+        request = context.switch_to_request()
+        if request.headers.get("ellar"):
+            return PlainTextResponse("middleware_return_response returned a response")
+        await call_next()
+
+
+def test_middleware_modifying_response():
+    tm = TestClientFactory.create_test_module_from_module(ModuleMiddleware)
+    client = tm.get_client()
+
+    response = client.get("/")
+    assert response.status_code == 200
+    assert response.headers["modified-header"] == "Ellar"
+
+
+def test_middleware_modifying_request():
+    tm = TestClientFactory.create_test_module_from_module(ModuleMiddleware)
+    client = tm.get_client()
+
+    response = client.get("/", headers={"set-user": "set"})
+    assert response.status_code == 200
+    assert response.json() == {"username": "Ellar"}
+
+
+def test_middleware_returns_response():
+    tm = TestClientFactory.create_test_module_from_module(ModuleMiddleware)
+    client = tm.get_client()
+
+    response = client.get("/", headers={"ellar": "set"})
+    assert response.status_code == 200
+    assert response.text == "middleware_return_response returned a response"