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{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"allOf with cross-file  does not qualify nested type references from source schema","articleBody":"### Description\n\nWhen using `allOf` to extend a schema from another file, oapi-codegen flattens the fields correctly but does not qualify nested type references that originate from the source schema's file. This produces uncompilable Go code.\n\n### Reproduction\n\nGiven two OpenAPI spec files with an `import-mapping` configured:\n\n**`api/common/openapi.yaml`**\n```yaml\nopenapi: 3.0.0\ninfo:\n  title: Common\n  version: 0.1.0\npaths: {}\ncomponents:\n  schemas:\n    Role:\n      type: string\n      enum: [admin, user]\n    User:\n      type: object\n      required: [id, username]\n      properties:\n        id:\n          type: string\n        username:\n          type: string\n        roles:\n          type: array\n          items:\n            $ref: '#/components/schemas/Role'\n```\n\n**`api/service/openapi.yaml`**\n```yaml\nopenapi: 3.0.0\ninfo:\n  title: Service\n  version: 0.1.0\npaths: {}\ncomponents:\n  schemas:\n    EnrichedUser:\n      allOf:\n      - $ref: '../common/openapi.yaml#/components/schemas/User'\n      - type: object\n        properties:\n          extra_field:\n            type: string\n```\n\n**`api/service/types.yaml`** (codegen config)\n```yaml\npackage: service\ngenerate:\n  models: true\noutput: types.gen.go\nimport-mapping:\n  '../common/openapi.yaml': common github.com/example/api/common\n```\n\n### Expected behavior\n\nGenerated `EnrichedUser` should qualify the `Role` reference via the import mapping:\n\n```go\ntype EnrichedUser struct {\n    ExtraField *string        `json:\"extra_field,omitempty\"`\n    ID         string         `json:\"id\"`\n    Roles      *[]common.Role `json:\"roles,omitempty\"`\n    Username   string         `json:\"username\"`\n}\n```\n\n### Actual behavior\n\nGenerated code uses an unqualified `Role` reference:\n\n```go\ntype EnrichedUser struct {\n    ExtraField *string    `json:\"extra_field,omitempty\"`\n    ID         string     `json:\"id\"`\n    Roles      *[]Role    `json:\"roles,omitempty\"`  // \u003c-- unqualified\n    Username   string     `json:\"username\"`\n}\n```\n\nThis fails to compile: `undefined: Role`\n\n### Workaround\n\nOverride the field in the `allOf` extension with a direct cross-file `$ref`:\n\n```yaml\n    EnrichedUser:\n      allOf:\n      - $ref: '../common/openapi.yaml#/components/schemas/User'\n      - type: object\n        properties:\n          roles:\n            type: array\n            items:\n              $ref: '../common/openapi.yaml#/components/schemas/Role'\n          extra_field:\n            type: string\n```\n\nThis correctly generates `Roles *[]common.Role`.\n\n### Version\n\noapi-codegen v2.6.0","author":{"url":"https://github.com/xiongzubiao","@type":"Person","name":"xiongzubiao"},"datePublished":"2026-03-10T18:04:58Z","url":"https://github.com/oapi-codegen/oapi-codegen/issues/2288"}