Migrate list_issues tool from REST to GraphQL API

Overview

The key requirement was to ignore PRs when the list_issues tool was used. As per #790. To accomplish this, the tool had to be migrated away from the REST API, as this was not an allowed request. Therefore this PR migrates the list_issues tool from GitHub's REST API to GraphQL API, bringing it in line with other tools like list_discussions. The migration provides cursor-based pagination, improved filtering, and better performance.

Key Changes

• API Migration: Switched from github.Client (REST) to githubv4.Client (GraphQL)
• Pagination: Migrated from page-based to cursor-based (after, perPage)
• Dynamic Queries: Conditional GraphQL queries based on labels and date filtering
• New Features: Added since parameter for date filtering (ISO 8601 format)
• Enhanced Performance: GraphQL's selective field querying reduces payload size

GraphQL vs REST

Parameter Updates:

• page → after (cursor-based pagination)
• sort → orderBy with new enum values
• State values: "open" → "OPEN", "closed" → "CLOSED"
• Direction values: "asc" → "ASC", "desc" → "DESC"
• Order fields: "created" → "CREATED_AT", "updated" → "UPDATED_AT"

Implementation

Dynamic Query Selection: Factory pattern selects appropriate GraphQL query based on filtering requirements (4 query types: base, with labels, with since, with both).

Fragment Architecture: Reusable IssueFragment with common interface for consistent data conversion.

Testing & Quality

• Updated tests to use GraphQL mocking with githubv4mock
• Comprehensive coverage: tool definition, dynamic queries, fragment conversion
• Updated README.md with new parameter descriptions
• All linting checks pass

This migration provides better performance, consistent API patterns, and enhanced filtering while maintaining backward compatibility. 🚀

Before & After

Before: Returns correct info (but included PRs) and lots of URLs.
[ { "id": 1234567890, "number": 842, "state": "open", "locked": false, "title": "[sanitized] Tool reports success when a non-existent repo owner is used", "body": "[sanitized] Bug description with reproduction steps...", "author_association": "NONE", "user": { "login": "[username]", "id": 12345678, "node_id": "[sanitized_node_id]", "avatar_url": "[sanitized_avatar_url]", "html_url": "[sanitized_profile_url]", "gravatar_id": "", "type": "User", "site_admin": false, "url": "[sanitized_api_url]", "events_url": "[sanitized_events_url]", "following_url": "[sanitized_following_url]", "followers_url": "[sanitized_followers_url]", "gists_url": "[sanitized_gists_url]", "organizations_url": "[sanitized_orgs_url]", "received_events_url": "[sanitized_received_events_url]", "repos_url": "[sanitized_repos_url]", "starred_url": "[sanitized_starred_url]", "subscriptions_url": "[sanitized_subscriptions_url]" }, "labels": [ { "id": 1234567890, "url": "[sanitized_label_url]", "name": "bug", "color": "d73a4a", "description": "Something isn't working", "default": true, "node_id": "[sanitized_node_id]" } ], "comments": 0, "created_at": "2025-08-08T02:29:19Z", "updated_at": "2025-08-08T07:32:39Z", "url": "[sanitized_api_url]", "html_url": "[sanitized_web_url]", "comments_url": "[sanitized_comments_url]", "events_url": "[sanitized_events_url]", "labels_url": "[sanitized_labels_url]", "repository_url": "[sanitized_repo_url]", "reactions": { "total_count": 0, "+1": 0, "-1": 0, "laugh": 0, "confused": 0, "heart": 0, "hooray": 0, "rocket": 0, "eyes": 0, "url": "[sanitized_reactions_url]" }, "node_id": "[sanitized_node_id]" } ]

After: Reduction in context, avoiding unnecessary URLs, irrelevant data and does not return PRs.

{ "issues": [ { "id": 1234567890, "number": 1234, "state": "OPEN", "title": "[sanitized] Sample issue title", "body": "[sanitized] Issue description and reproduction steps...", "user": { "login": "[username]" }, "labels": [ { "name": "bug", "description": "Something isn't working", "node_id": "[sanitized_node_id]" } ], "created_at": "2025-08-07T17:21:22Z", "updated_at": "2025-08-07T17:21:22Z" } ], "pageInfo": { "endCursor": "[base64_cursor]", "hasNextPage": true, "hasPreviousPage": false, "startCursor": "[base64_cursor]" }, "totalCount": 622 }