Remove EnableOneOf option

[glen-84]

Summary of the changes (Less than 80 chars)

• Remove EnableOneOf option.

[Copilot]

Pull request overview

This pull request removes the EnableOneOf configuration option from HotChocolate v16, as the @oneOf directive is now a built-in feature that no longer requires opt-in configuration. The changes ensure that OneOf functionality is always available without requiring users to explicitly enable it through schema options.

Changes:

• Removed EnableOneOf property from IReadOnlySchemaOptions interface and SchemaOptions class
• Updated introspection type __Type to always include the isOneOf field instead of conditionally
• Moved OneOfDirectiveType registration from conditional to always-registered alongside other core directives
• Updated v16 documentation to remove references to the configuration option and added migration guidance

Reviewed changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
website/src/docs/hotchocolate/v16/migrating/migrate-from-15-to-16.md	Added migration documentation explaining the removal of the EnableOneOf option
website/src/docs/hotchocolate/v16/defining-a-schema/input-object-types.md	Removed .ModifyOptions(o => o.EnableOneOf = true) from code example since it's no longer needed
src/HotChocolate/Core/src/Types/IReadOnlySchemaOptions.cs	Removed EnableOneOf property from the interface
src/HotChocolate/Core/src/Types/SchemaOptions.cs	Removed EnableOneOf property and its initialization from the class
src/HotChocolate/Core/src/Types/Types/Introspection/__Type.cs	Made isOneOf field always available instead of conditional on EnableOneOf option
src/HotChocolate/Core/src/Types/Configuration/BuiltInDirectiveTypeReferences.cs	Moved OneOfDirectiveType registration from conditional to always-registered with core directives
src/HotChocolate/Core/test/Types.Tests/Configuration/__snapshots__/*.snap	Updated test snapshots to reflect new ordering where OneOfDirectiveType is registered after core directives

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 0.00%. Comparing base (924f3dc) to head (6fc7ea0).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@     Coverage Diff      @@
##   main   #9177   +/-   ##
============================
============================

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[github-actions]

Fusion Gateway Performance Results

Simple Composite Query

	Req/s	Err%
Constant (50 VUs)	2930.57	0.00%
Ramping (0-500-0 VUs)	3093.00	0.00%

Response Times & Query

	Min	Med	Avg	P90	P95	Max
Constant	0.76ms	15.08ms	16.84ms	30.95ms	36.44ms	172.74ms
Ramping	0.72ms	70.05ms	71.97ms	135.01ms	154.59ms	294.03ms

query TestQuery {
  topProducts(first: 5) {
    inStock
    name
    price
    shippingEstimate
    upc
    weight
    reviews {
      id
      body
      author {
        id
        username
        name
      }
    }
  }
}

---

Deep Recursion Query

	Req/s	Err%
Constant (50 VUs)	752.50	0.00%
Ramping (0-500-0 VUs)	830.19	0.00%

Response Times & Query

	Min	Med	Avg	P90	P95	Max
Constant	9.06ms	61.56ms	64.93ms	80.99ms	90.17ms	354.77ms
Ramping	1.83ms	255.10ms	257.75ms	503.35ms	535.65ms	642.15ms

query TestQuery {
  users {
    id
    username
    name
    reviews {
      id
      body
      product {
        inStock
        name
        price
        shippingEstimate
        upc
        weight
        reviews {
          id
          body
          author {
            id
            username
            name
            reviews {
              id
              body
              product {
                inStock
                name
                price
                shippingEstimate
                upc
                weight
              }
            }
          }
        }
      }
    }
  }
  topProducts(first: 5) {
    inStock
    name
    price
    shippingEstimate
    upc
    weight
    reviews {
      id
      body
      author {
        id
        username
        name
        reviews {
          id
          body
          product {
            inStock
            name
            price
            shippingEstimate
            upc
            weight
          }
        }
      }
    }
  }
}

---

Variable Batching Throughput

	Req/s	Err%
Constant (50 VUs)	23246.69	0.00%
Ramping (0-500-0 VUs)	18299.60	0.00%

Response Times & Query

	Min	Med	Avg	P90	P95	Max
Constant	0.10ms	1.74ms	2.10ms	4.00ms	4.89ms	46.75ms
Ramping	0.10ms	9.46ms	11.51ms	23.65ms	28.56ms	106.69ms

query TestQuery($upc: ID!, $price: Long!, $weight: Long!) {
  productByUpc(upc: $upc) {
    inStock
    shippingEstimate(weight: $weight, price: $price)
  }
}

Variables (5 sets batched per request)

[
  { "upc": "1", "price": 899, "weight": 100 },
  { "upc": "2", "price": 1299, "weight": 1000 },
  { "upc": "3", "price": 15, "weight": 20 },
  { "upc": "4", "price": 499, "weight": 100 },
  { "upc": "5", "price": 1299, "weight": 1000 }
]

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Run 22307241164 • Commit 302b890 • Mon, 23 Feb 2026 13:19:58 GMT