feat(relay): add offset argument to relay connection (#339)

[mini0n-ai]

Summary

Add argument to relay connections, enabling first/offset pagination with proper ( and ) tracking.

Resolves #339
/claim #339

Details

• Added argument to for relay connections.
• Implemented helper to adjust/create an cursor based on integer offset for cursor calculations while preserving Relay pagination semantics.
• Updated and to convert offset into cursor and pass through.
• Added offset support to and with proper resolution when offset > 0.
• Updated optimizer prefetching window pagination to account for parameter.
• Added comprehensive unit tests in verifying first/offset pagination, cursor bounds, pageInfo state, and negative offset validation.

Settlement

• Base L2 Sovereign Wallet:

Summary by Sourcery

Enable offset-based pagination for Relay connections while preserving cursor pagination semantics and accurate page metadata.

New Features:

• Add an offset argument to Relay connections for offset-based pagination alongside cursor pagination.

Bug Fixes:

• Ensure Relay page information and cursor bounds correctly reflect non-zero offsets, including optimized queryset pagination.

Enhancements:

• Provide shared offset-to-cursor handling with validation for negative offsets and compatibility with existing after cursors.

Tests:

• Add coverage for zero, non-zero, last-page, and negative-offset connection pagination scenarios.

[botberry]

Thanks for adding the RELEASE.md file!

Below is the changelog that will be used for the release.

---

Add offset argument to relay connections for first/after and last/before pagination.

This release was contributed by @mini0n-ai in #956

[sourcery-ai]

Hey - I've found 2 issues

Prompt for AI Agents

Please address the comments from this code review:

## Individual Comments

### Comment 1
<location path="strawberry_django/relay/list_connection.py" line_range="104-108" />
<code_context>
                 field_ = unwrap_type(field_)
                 edge_class = cast("Edge", field_)

+                after = resolve_offset_to_after(
+                    field_kwargs.get("offset"),
+                    field_kwargs.get("after"),
+                    prefix=edge_class.CURSOR_PREFIX,
+                )
                 slice_metadata = SliceMetadata.from_arguments(
                     Info(_raw_info=info, _field=field),
</code_context>
<issue_to_address>
**issue (bug_risk):** For optimized queryset connections using the `last`-only path, `offset` is first folded into `after` and then forwarded unchanged to `resolve_optimized_last_connection`, whose recursive `resolve_connection` folds the same offset into the already-adjusted cursor a second time. The query therefore starts too far into the list and returns the wrong page.

**Triggers:** When a queryset-backed list connection is optimized and queried with `last` plus a positive `offset` and no `before` cursor.

**Suggested fix:** Pass the original `after` and offset only once, or clear `offset` after converting it into `after` before entering `resolve_optimized_last_connection`.

```suggestion
            after = resolve_offset_to_after(
                offset,
                after,
                prefix=edge_class.CURSOR_PREFIX,
            )
            offset = None
```
</issue_to_address>

### Comment 2
<location path="strawberry_django/relay/cursor_connection.py" line_range="260-261" />
<code_context>
         if first > max_results:
             raise ValueError(f"Argument 'first' cannot be higher than {max_results}.")
-        slice_ = slice(first + 1)
+        start = offset or 0
+        slice_ = slice(start, start + first + 1)
     elif last is not None:
         # when using last, optimize by reversing the QuerySet ordering in the DB,
</code_context>
<issue_to_address>
**issue (bug_risk):** Negative offsets are not validated in cursor-backed connections before constructing the queryset slice. For nested connections that use window pagination, the negative offset is treated as a valid row-number boundary and returns an incorrect page instead of raising the required non-negative-offset error.

**Triggers:** When a cursor connection is nested or otherwise uses `related_field_id` and receives `offset < 0`.

**Suggested fix:** Validate `offset < 0` in `apply_cursor_pagination` before applying either queryset slicing or window pagination.
</issue_to_address>

Sourcery assessment

Approval pending. 2 findings to address first.

Blocking findings: strawberry_django/relay/list_connection.py:108, strawberry_django/relay/cursor_connection.py:261

---

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[sourcery-ai]

Sourcery assessment

Approved.

[bellini666]

Hi @mini0n-ai ,

I'm trying to understand, what the use case of offset is here? Because, in general, first/last/before/after should be enough to deal with cases where you would need an offset, no?