feat(devops): add out-of-the-box Prometheus metrics and Grafana observability stack

apps/api/plane/tests/unit/utils/test_paginator.py

@@ -0,0 +1,81 @@
+# Copyright (c) 2023-present Plane Software, Inc. and contributors
+# SPDX-License-Identifier: AGPL-3.0-only
+# See the LICENSE file for details.
+
+import pytest
+from rest_framework.test import APIRequestFactory
+
+from plane.utils.paginator import BasePaginator, Cursor, CursorResult
+
+
+class OffsetEchoPaginator:
+    def get_result(self, limit=1000, cursor=None):
+        has_next = cursor.offset < 1
+        return CursorResult(
+            results=[{"page_offset": cursor.offset}],
+            next=Cursor(limit, cursor.offset + 1, False, has_next),
+            prev=Cursor(limit, cursor.offset - 1, True, cursor.offset > 0),
+            hits=2,
+            max_hits=2,
+        )
+
+
+@pytest.mark.unit
+class TestBasePaginatorPageSupport:
+    def setup_method(self):
+        self.base_paginator = BasePaginator()
+        self.factory = APIRequestFactory()
+
+    @pytest.mark.parametrize(
+        ("page", "expected_offset"),
+        [
+            ("1", 0),
+            ("2", 1),
+        ],
+    )
+    def test_paginate_honors_explicit_page_parameter(self, page, expected_offset):
+        request = self.factory.get("/", {"page": page, "per_page": "10"})
+
+        response = self.base_paginator.paginate(request=request, paginator=OffsetEchoPaginator())
+
+        assert response.data["results"][0]["page_offset"] == expected_offset
+
+    def test_paginate_returns_no_next_cursor_on_last_page(self):
+        request = self.factory.get("/", {"page": "2", "per_page": "10"})
+
+        response = self.base_paginator.paginate(request=request, paginator=OffsetEchoPaginator())
+
+        assert response.data["next_page_results"] is False
+        assert response.data["next_cursor"] is None
+
+    def test_following_next_cursor_metadata_terminates(self):
+        class TwoPagePaginator:
+            def get_result(self, limit=1000, cursor=None):
+                has_next = cursor.offset == 0
+                return CursorResult(
+                    results=[{"page_offset": cursor.offset}],
+                    next=Cursor(limit, cursor.offset + 1, False, has_next),
+                    prev=Cursor(limit, cursor.offset - 1, True, cursor.offset > 0),
+                    hits=3,
+                    max_hits=2,
+                )
+
+        seen_offsets = []
+        next_cursor = None
+        paginator = TwoPagePaginator()
+
+        for _ in range(5):
+            params = {"per_page": "2"}
+            if next_cursor:
+                params["cursor"] = next_cursor
+
+            request = self.factory.get("/", params)
+            response = self.base_paginator.paginate(request=request, paginator=paginator)
+
+            seen_offsets.append(response.data["results"][0]["page_offset"])
+            next_cursor = response.data["next_cursor"]
+            if not next_cursor:
+                break
+
+        assert seen_offsets == [0, 1]
+        assert next_cursor is None

apps/api/plane/utils/paginator.py

@@ -674,10 +674,26 @@ def paginate(
         per_page = self.get_per_page(request, default_per_page, max_per_page)
         # Convert the cursor value to integer and float from string
         input_cursor = None
-        try:
-            input_cursor = cursor_cls.from_string(request.GET.get(self.cursor_name, f"{per_page}:0:0"))
-        except ValueError:
-            raise ParseError(detail="Invalid cursor parameter.")
+        input_cursor_value = request.GET.get(self.cursor_name)
+        page_value = request.GET.get("page")
+
+        if input_cursor_value is not None:
+            try:
+                input_cursor = cursor_cls.from_string(input_cursor_value)
+            except ValueError:
+                raise ParseError(detail="Invalid cursor parameter.")
+        elif page_value is not None:
+            try:
+                page_number = int(page_value)
+            except ValueError:
+                raise ParseError(detail="Page parameter must be a valid integer.")
+
+            if page_number < 1:
+                raise ParseError(detail="Page parameter must be greater than or equal to 1.")
+
+            input_cursor = cursor_cls(per_page, page_number - 1, False)
+        else:
+            input_cursor = cursor_cls(per_page, 0, False)
 
         if not paginator:
             if group_by_field_name:
@@ -718,7 +734,7 @@ def paginate(
                 "grouped_by": group_by_field_name,
                 "sub_grouped_by": sub_group_by_field_name,
                 "total_count": (cursor_result.hits),
-                "next_cursor": str(cursor_result.next),
+                "next_cursor": str(cursor_result.next) if cursor_result.next.has_results else None,
                 "prev_cursor": str(cursor_result.prev),
                 "next_page_results": cursor_result.next.has_results,
                 "prev_page_results": cursor_result.prev.has_results,