New View base class (#2080)

* New View base class, closes #2078
* Use new View subclass for PatternPortfolioView

tests/test_base_view.py

@@ -0,0 +1,84 @@
+from datasette.views.base import View
+from datasette import Request, Response
+from datasette.app import Datasette
+import json
+import pytest
+
+
+class GetView(View):
+    async def get(self, request, datasette):
+        return Response.json(
+            {
+                "absolute_url": datasette.absolute_url(request, "/"),
+                "request_path": request.path,
+            }
+        )
+
+
+class GetAndPostView(GetView):
+    async def post(self, request, datasette):
+        return Response.json(
+            {
+                "method": request.method,
+                "absolute_url": datasette.absolute_url(request, "/"),
+                "request_path": request.path,
+            }
+        )
+
+
+@pytest.mark.asyncio
+async def test_get_view():
+    v = GetView()
+    datasette = Datasette()
+    response = await v(Request.fake("/foo"), datasette)
+    assert json.loads(response.body) == {
+        "absolute_url": "http://localhost/",
+        "request_path": "/foo",
+    }
+    # Try a HEAD request
+    head_response = await v(Request.fake("/foo", method="HEAD"), datasette)
+    assert head_response.body == ""
+    assert head_response.status == 200
+    # And OPTIONS
+    options_response = await v(Request.fake("/foo", method="OPTIONS"), datasette)
+    assert options_response.body == "ok"
+    assert options_response.status == 200
+    assert options_response.headers["allow"] == "HEAD, GET"
+    # And POST
+    post_response = await v(Request.fake("/foo", method="POST"), datasette)
+    assert post_response.body == "Method not allowed"
+    assert post_response.status == 405
+    # And POST with .json extension
+    post_json_response = await v(Request.fake("/foo.json", method="POST"), datasette)
+    assert json.loads(post_json_response.body) == {
+        "ok": False,
+        "error": "Method not allowed",
+    }
+    assert post_json_response.status == 405
+
+
+@pytest.mark.asyncio
+async def test_post_view():
+    v = GetAndPostView()
+    datasette = Datasette()
+    response = await v(Request.fake("/foo"), datasette)
+    assert json.loads(response.body) == {
+        "absolute_url": "http://localhost/",
+        "request_path": "/foo",
+    }
+    # Try a HEAD request
+    head_response = await v(Request.fake("/foo", method="HEAD"), datasette)
+    assert head_response.body == ""
+    assert head_response.status == 200
+    # And OPTIONS
+    options_response = await v(Request.fake("/foo", method="OPTIONS"), datasette)
+    assert options_response.body == "ok"
+    assert options_response.status == 200
+    assert options_response.headers["allow"] == "HEAD, GET, POST"
+    # And POST
+    post_response = await v(Request.fake("/foo", method="POST"), datasette)
+    assert json.loads(post_response.body) == {
+        "method": "POST",
+        "absolute_url": "http://localhost/",
+        "request_path": "/foo",
+    }