fix prev offset

CHANGES.md

@@ -6,6 +6,10 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/).
 
 Note: Minor version `0.X.0` update might break the API, It's recommended to pin `tipg` to minor version: `tipg>=0.1,<0.2`
 
+## [0.5.5] - 2023-12-19
+
+- Fix `prev` offset value
+
 ## [0.5.4] - 2023-12-19
 
 - Fix decimal error for streaming responses (author @RemcoMeeuwissen, https://github.com/developmentseed/tipg/pull/148)
@@ -247,7 +251,8 @@ Note: Minor version `0.X.0` update might break the API, It's recommended to pin
 
 - Initial release
 
-[unreleased]: https://github.com/developmentseed/tipg/compare/0.5.4...HEAD
+[unreleased]: https://github.com/developmentseed/tipg/compare/0.5.5...HEAD
+[0.5.5]: https://github.com/developmentseed/tipg/compare/0.5.4...0.5.5
 [0.5.4]: https://github.com/developmentseed/tipg/compare/0.5.3...0.5.4
 [0.5.3]: https://github.com/developmentseed/tipg/compare/0.5.2...0.5.3
 [0.5.2]: https://github.com/developmentseed/tipg/compare/0.5.1...0.5.2

tests/routes/test_items.py

@@ -84,6 +84,31 @@ def test_items_limit_and_offset(app):
     response = app.get("/collections/public.landsat_wrs/items?limit=10001")
     assert response.status_code == 422
 
+    response = app.get("/collections/public.landsat_wrs/items?limit=100&offset=100")
+    assert response.status_code == 200
+    assert response.headers["content-type"] == "application/geo+json"
+    body = response.json()
+    assert len(body["features"]) == 100
+    assert body["numberMatched"] == 16269
+    assert body["numberReturned"] == 100
+    # Next
+    assert "limit=100&offset=200" in body["links"][2]["href"]
+    # Prev
+    assert "limit=100&offset=0" in body["links"][3]["href"]
+
+    # offset + limit overflow the total number of items
+    response = app.get("/collections/public.landsat_wrs/items?limit=100&offset=16200")
+    assert response.status_code == 200
+    assert response.headers["content-type"] == "application/geo+json"
+    body = response.json()
+    assert len(body["features"]) == 69
+    assert body["numberMatched"] == 16269
+    assert body["numberReturned"] == 69
+    # No NEXT link
+    assert "next" not in [link["rel"] for link in body["links"]]
+    # Prev
+    assert "limit=100&offset=16100" in body["links"][2]["href"]
+
 
 def test_items_bbox(app):
     """Test /items endpoint with bbox options."""

tipg/collections.py

@@ -742,7 +742,9 @@ async def features(
         function_parameters: Optional[Dict[str, str]] = None,
     ) -> ItemList:
         """Build and run Pg query."""
+        limit = limit or features_settings.default_features_limit
         offset = offset or 0
+
         function_parameters = function_parameters or {}
 
         if geom and geom.lower() != "none" and not self.get_geometry_column(geom):
@@ -792,7 +794,7 @@ async def features(
             items=features,
             matched=matched,
             next=offset + returned if matched - returned > offset else None,
-            prev=max(offset - returned, 0) if offset else None,
+            prev=max(offset - limit, 0) if offset else None,
         )
 
     async def get_tile(