mrr_mini_dataset.json

{
  "metadata": {
    "version": "1.0-sample",
    "total_cases": 50,
    "description": "Mini sample of Chronos MRR benchmark for quick testing",
    "full_benchmark_info": "Complete 5000-case benchmark available Q1 2026"
  },
  "test_cases": [
    {
      "bug_id": "mrr_syntax_001",
      "category": "syntax",
      "difficulty": "easy",
      "language": "python",
      "repository_size": "small",
      "description": "Missing closing parenthesis in data processing function",
      "symptoms": ["SyntaxError: unexpected EOF while parsing"],
      "scattered_context": {
        "data_processor.py": {
          "relevance": "critical",
          "function": "process_items",
          "error_line": 45
        },
        "test_processor.py": {
          "relevance": "high",
          "failing_test": "test_process_positive_items"
        }
      },
      "ground_truth": {
        "root_cause": "Missing closing parenthesis in list comprehension",
        "fix_type": "add_syntax",
        "files_modified": 1,
        "test_status": "all_pass"
      }
    },
    {
      "bug_id": "mrr_logic_042",
      "category": "logic",
      "difficulty": "medium",
      "language": "javascript",
      "repository_size": "medium",
      "description": "Incorrect boundary check in pagination logic",
      "symptoms": ["Last page shows duplicate items", "PageCount off by one"],
      "scattered_context": {
        "pagination.js": {
          "relevance": "critical",
          "function": "calculatePages",
          "issue": "Wrong inequality operator"
        },
        "api/routes.js": {
          "relevance": "high",
          "usage": "Calls pagination.calculatePages"
        },
        "tests/pagination.test.js": {
          "relevance": "high",
          "failing_tests": ["test_last_page", "test_boundary_conditions"]
        },
        "commits/abc123": {
          "relevance": "medium",
          "date": "2 months ago",
          "message": "Refactored pagination logic"
        }
      },
      "ground_truth": {
        "root_cause": "Off-by-one error: should use <= instead of <",
        "fix_location": "pagination.js:calculatePages:line87",
        "fix_type": "operator_change",
        "files_modified": 1
      }
    },
    {
      "bug_id": "mrr_null_087",
      "category": "memory",
      "difficulty": "medium",
      "language": "java",
      "repository_size": "large",
      "description": "NullPointerException in user session management",
      "symptoms": [
        "NPE when user logs out and immediately logs back in",
        "Occurs only in production environment"
      ],
      "scattered_context": {
        "auth/SessionManager.java": {
          "relevance": "critical",
          "method": "invalidateSession",
          "issue": "Doesn't clear cache properly"
        },
        "cache/RedisCache.java": {
          "relevance": "critical",
          "method": "delete",
          "issue": "Returns null on cache miss"
        },
        "controllers/AuthController.java": {
          "relevance": "high",
          "usage": "Calls SessionManager methods"
        },
        "config/prod.properties": {
          "relevance": "medium",
          "difference": "Cache TTL different from dev"
        },
        "logs/production.log": {
          "relevance": "high",
          "stacktrace": "Shows NPE origin"
        }
      },
      "ground_truth": {
        "root_cause": "Session invalidation doesn't wait for cache deletion confirmation",
        "fix_type": "add_null_check",
        "files_modified": 2,
        "requires_sync": true
      }
    },
    {
      "bug_id": "mrr_race_156",
      "category": "concurrency",
      "difficulty": "hard",
      "language": "python",
      "repository_size": "medium",
      "description": "Race condition in distributed task queue causing duplicate processing",
      "symptoms": [
        "Same task processed multiple times",
        "Happens under high load",
        "Database shows duplicate entries"
      ],
      "scattered_context": {
        "workers/task_processor.py": {
          "relevance": "critical",
          "class": "TaskProcessor",
          "method": "claim_task",
          "issue": "Not atomic"
        },
        "db/models.py": {
          "relevance": "critical",
          "model": "Task",
          "missing": "Unique constraint on processing"
        },
        "queue/redis_queue.py": {
          "relevance": "high",
          "method": "dequeue",
          "issue": "No distributed lock"
        },
        "tests/load_test.py": {
          "relevance": "medium",
          "note": "Doesn't test concurrent workers"
        },
        "monitoring/metrics.py": {
          "relevance": "medium",
          "shows": "Duplicate processing spike times"
        }
      },
      "ground_truth": {
        "root_cause": "Task claiming not atomic across distributed workers",
        "fix_type": "add_distributed_lock",
        "solution": "Implement Redis-based distributed lock with TTL",
        "files_modified": 3
      }
    },
    {
      "bug_id": "mrr_api_203",
      "category": "api",
      "difficulty": "medium",
      "language": "javascript",
      "repository_size": "small",
      "description": "Breaking change after upgrading payment SDK from v2 to v3",
      "symptoms": [
        "TypeError: stripe.charges.create is not a function",
        "All payment processing fails"
      ],
      "scattered_context": {
        "payment/processor.js": {
          "relevance": "critical",
          "usage": "Old v2 API patterns"
        },
        "package.json": {
          "relevance": "critical",
          "change": "stripe: ^2.0.0 -> ^3.0.0"
        },
        "migrations/stripe_v3.md": {
          "relevance": "high",
          "location": "docs/migrations/",
          "unread": true
        },
        "tests/payment.test.js": {
          "relevance": "high",
          "status": "All failing"
        },
        "config/stripe.js": {
          "relevance": "medium",
          "note": "Config format also changed"
        }
      },
      "ground_truth": {
        "root_cause": "Stripe v3 changed API structure - charges is now paymentIntents",
        "fix_type": "api_migration",
        "migration_guide": "docs/migrations/stripe_v3.md",
        "files_modified": 4
      }
    },
    {
      "bug_id": "mrr_perf_089",
      "category": "performance",
      "difficulty": "hard",
      "language": "python",
      "repository_size": "large",
      "description": "Dashboard load time increased from 2s to 45s after new feature",
      "symptoms": [
        "Dashboard timeout errors",
        "Database CPU at 100%",
        "Started after commit def456"
      ],
      "scattered_context": {
        "dashboard/views.py": {
          "relevance": "critical",
          "function": "get_user_analytics",
          "new_feature": "Real-time activity feed"
        },
        "models/activity.py": {
          "relevance": "critical",
          "issue": "Missing database index"
        },
        "api/serializers.py": {
          "relevance": "high",
          "issue": "N+1 query in activity serializer"
        },
        "requirements.txt": {
          "relevance": "medium",
          "note": "ORM version upgrade might help"
        },
        "monitoring/slow_query.log": {
          "relevance": "high",
          "shows": "Repeated full table scans"
        }
      },
      "ground_truth": {
        "root_cause": "N+1 query problem with missing index on activity.user_id",
        "fix_type": "add_index_and_prefetch",
        "performance_gain": "45s -> 1.8s",
        "files_modified": 3
      }
    },
    {
      "bug_id": "mrr_logic_108",
      "category": "logic",
      "difficulty": "easy",
      "language": "java",
      "repository_size": "small",
      "description": "Discount calculation applies percentage as absolute value",
      "symptoms": [
        "50% discount reduces price by $50 instead of 50%",
        "Customer complaints about overcharging"
      ],
      "scattered_context": {
        "pricing/DiscountCalculator.java": {
          "relevance": "critical",
          "method": "applyDiscount",
          "line": 67
        },
        "tests/DiscountTest.java": {
          "relevance": "high",
          "note": "Test uses integer prices, bug hidden"
        }
      },
      "ground_truth": {
        "root_cause": "Missing division by 100 for percentage calculation",
        "fix_type": "arithmetic_fix",
        "fix": "price * (1 - discount/100.0)",
        "files_modified": 1
      }
    },
    {
      "bug_id": "mrr_memory_234",
      "category": "memory",
      "difficulty": "hard",
      "language": "javascript",
      "repository_size": "medium",
      "description": "Memory leak in WebSocket event handlers causing server crashes",
      "symptoms": [
        "Server memory usage grows continuously",
        "Crashes after ~1000 connections",
        "Heap snapshots show detached DOM references"
      ],
      "scattered_context": {
        "websocket/client.js": {
          "relevance": "critical",
          "issue": "Event listeners not removed on disconnect"
        },
        "websocket/server.js": {
          "relevance": "critical",
          "issue": "Stores all client references"
        },
        "utils/events.js": {
          "relevance": "high",
          "pattern": "Similar leak pattern"
        },
        "monitoring/heap_dumps/": {
          "relevance": "high",
          "files": ["dump1.heapsnapshot", "dump2.heapsnapshot"]
        },
        "nginx/logs/error.log": {
          "relevance": "medium",
          "shows": "Worker process OOM kills"
        }
      },
      "ground_truth": {
        "root_cause": "WebSocket cleanup doesn't remove all event listeners",
        "fix_type": "cleanup_handlers",
        "solution": "Implement proper cleanup in disconnect handler",
        "files_modified": 2
      }
    },
    {
      "bug_id": "mrr_syntax_045",
      "category": "syntax",
      "difficulty": "easy",
      "language": "python",
      "repository_size": "small",
      "description": "IndentationError in config parser after team member used tabs",
      "symptoms": ["IndentationError: unexpected indent", "CI/CD pipeline fails"],
      "scattered_context": {
        "config/parser.py": {
          "relevance": "critical",
          "line_range": [45, 52],
          "issue": "Mixed tabs and spaces"
        },
        ".editorconfig": {
          "relevance": "medium",
          "missing": true
        }
      },
      "ground_truth": {
        "root_cause": "Mixed indentation (tabs vs spaces) in parser.py",
        "fix_type": "fix_indentation",
        "files_modified": 1
      }
    },
    {
      "bug_id": "mrr_concurrency_312",
      "category": "concurrency",
      "difficulty": "medium",
      "language": "java",
      "repository_size": "large",
      "description": "Deadlock in payment processing under high load",
      "symptoms": [
        "Thread dump shows circular wait",
        "Happens when >50 concurrent payments",
        "System hangs, requires restart"
      ],
      "scattered_context": {
        "payment/PaymentService.java": {
          "relevance": "critical",
          "methods": ["processPayment", "updateInventory"],
          "issue": "Lock ordering differs"
        },
        "inventory/InventoryService.java": {
          "relevance": "critical",
          "methods": ["reserve", "release"],
          "issue": "Opposite lock order"
        },
        "docs/architecture.md": {
          "relevance": "medium",
          "section": "Locking Strategy",
          "outdated": true
        },
        "monitoring/thread_dumps/": {
          "relevance": "high",
          "files": ["deadlock1.txt", "deadlock2.txt"]
        }
      },
      "ground_truth": {
        "root_cause": "Inconsistent lock ordering between payment and inventory",
        "fix_type": "fix_lock_ordering",
        "solution": "Establish global lock ordering protocol",
        "files_modified": 2
      }
    }
  ],
  "additional_cases_reference": "See mrr_sample_dataset.json for 500 test cases"
}