[Fusion] Added support for merging @cost and @listSize directives

[glen-84]

Summary of the changes (Less than 80 chars)

• [Fusion] Added support for merging @cost and @listSize directives.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 0.00%. Comparing base (35ed02f) to head (2abc8c9).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@     Coverage Diff      @@
##   main   #9057   +/-   ##
============================
============================

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[github-actions]

🚀 Fusion Gateway Performance Results

Simple Composite Query

Constant Load (50 VUs)

Requests/sec	Error Rate
5801.32 req/s	0.00%

📊 Response Time Metrics

Min	Med	Max	Avg	P90	P95
0.82ms	7.14ms	162.50ms	8.46ms	13.20ms	18.89ms

Ramping Load (0→50→500→50 VUs)

Requests/sec	Error Rate
4450.31 req/s	0.00%

📊 Response Time Metrics

Min	Med	Max	Avg	P90	P95
0.81ms	40.38ms	235.94ms	49.96ms	111.04ms	127.73ms

Executed Query

fragment User on User {
  id
  username
  name
}

fragment Review on Review {
  id
  body
}

fragment Product on Product {
  inStock
  name
  price
  shippingEstimate
  upc
  weight
}

query TestQuery {
  topProducts(first: 5) {
    ...Product
    reviews {
      ...Review
      author {
        ...User
      }
    }
  }
}

Deep Recursion Query

Constant Load (50 VUs)

Requests/sec	Error Rate
269.39 req/s	0.00%

📊 Response Time Metrics

Min	Med	Max	Avg	P90	P95
12.79ms	174.19ms	559.69ms	179.87ms	225.52ms	250.80ms

Ramping Load (0→50→500→50 VUs)

Requests/sec	Error Rate
304.64 req/s	0.00%

📊 Response Time Metrics

Min	Med	Max	Avg	P90	P95
3.05ms	672.57ms	1721.44ms	692.58ms	1383.29ms	1518.39ms

Executed Query

fragment User on User {
  id
  username
  name
}

fragment Review on Review {
  id
  body
}

fragment Product on Product {
  inStock
  name
  price
  shippingEstimate
  upc
  weight
}

query TestQuery {
  users {
    ...User
    reviews {
      ...Review
      product {
        ...Product
        reviews {
          ...Review
          author {
            ...User
            reviews {
              ...Review
              product {
                ...Product
              }
            }
          }
        }
      }
    }
  }
  topProducts(first: 5) {
    ...Product
    reviews {
      ...Review
      author {
        ...User
        reviews {
          ...Review
          product {
            ...Product
          }
        }
      }
    }
  }
}

Variable Batching Throughput

Constant Load (50 VUs)

Requests/sec	Error Rate
24091.11 req/s	0.00%

📊 Response Time Metrics

Min	Med	Max	Avg	P90	P95
0.09ms	1.67ms	44.45ms	2.03ms	3.86ms	4.72ms

Ramping Load (0→50→500→50 VUs)

Requests/sec	Error Rate
19106.37 req/s	0.00%

📊 Response Time Metrics

Min	Med	Max	Avg	P90	P95
0.09ms	8.98ms	109.78ms	11.03ms	22.88ms	27.53ms

Executed Query

query TestQuery_8f7a46ce_2(
  $__fusion_1_upc: ID!
  $__fusion_2_price: Long!
  $__fusion_2_weight: Long!
) {
  productByUpc(upc: $__fusion_1_upc) {
    inStock
    shippingEstimate(weight: $__fusion_2_weight, price: $__fusion_2_price)
  }
}

Variables (5 sets batched in single request)

[
  { "__fusion_1_upc": "1", "__fusion_2_price": 899, "__fusion_2_weight": 100 },
  { "__fusion_1_upc": "2", "__fusion_2_price": 1299, "__fusion_2_weight": 1000 },
  { "__fusion_1_upc": "3", "__fusion_2_price": 15, "__fusion_2_weight": 20 },
  { "__fusion_1_upc": "4", "__fusion_2_price": 499, "__fusion_2_weight": 100 },
  { "__fusion_1_upc": "5", "__fusion_2_price": 1299, "__fusion_2_weight": 1000 }
]

No baseline data available for comparison.

---

Run 21280451193 • Commit c783060 • Fri, 23 Jan 2026 09:17:09 GMT