[BUG] [Elixir] Invalid typespecs when using allOf and single schema reference

[efcasado]

Bug Report Checklist

• Have you provided a full/minimal spec to reproduce the issue?
• Have you validated the input using an OpenAPI validator (example)?
• Have you tested with the latest master to confirm the issue still exists?
• Have you searched for related issues/PRs?
• What's the actual output vs expected output?
• [Optional] Sponsorship to speed up the bug fix or feature request (example)

Description

When using the Elixir generator with model composition, the resulting type specifications can be both incorrect and invalid - leading to compilation errors in the generated Elixir client.

This issue manifests when an allOf composition references only a single schema. In such cases, the generated typespec looks like the following:

@spec bar(Tesla.Env.client(), keyword()) :: {:ok, OpenAPI.Model.any().t()} | {:error, Tesla.Env.t()}

Notice the problematic OpenAPI.Model.any().t(). This is not a valid Elixir type. At best, it should be any(), but ideally, the generator should produce the actual schema module, such as OpenAPI.Model.Bar200Response.t().

This suggests there are two separate problems:

• Type name normalization is failing and not treating any() as a terminal type.
• Schema resolution is not correctly identifying the intended model for the typespec.

openapi-generator version

7.12.0

OpenAPI declaration file content or url

openapi: 3.0.0
info:
  version: 1.0.0
  title: A minimal OpenAPI example
paths:
  /foo:
    get:
      operationId: foo
      responses:
        200:
          description: Successful operation
          content:
            application/json:
              schema:
                allOf:
                  - $ref: "#/components/schemas/Foo"
                  - $ref: "#/components/schemas/Bar"

  /bar:
    get:
      operationId: bar
      responses:
        200:
          description: Successful operation
          content:
            application/json:
              schema:
                allOf:
                  - $ref: "#/components/schemas/Foo"

components:
  schemas:
    Foo:
      type: object
      properties:
        foo_value:
          type: string

    Bar:
      type: object
      properties:
        bar_value:
          type: string

Generation Details

openapi-generator-cli generate -i $(OAS_FILE) -g elixir -o local/out/elixir

[efcasado]

In case it helps, these are the debug logs I got for foo and bar responses, respectively.

CodegenResponse{headers=[], code='200', is1xx='false', is2xx='false', is3xx='false', is4xx='false', is5xx='false', message='Successful operation', examples=null, dataType='AMinimalOpenAPIExample.Model.Foo200Response.t', baseType='Foo200Response', containerType='null', containerTypeMapped='null', hasHeaders=false, isString=false, isNumeric=false, isInteger=false, isShort=false, isLong=false, isUnboundedInteger=false, isNumber=false, isFloat=false, isDouble=false, isDecimal=false, isByteArray=false, isBoolean=false, isDate=false, isDateTime=false, isUuid=false, isEmail=false, isPassword=false, isModel=true, isFreeFormObject=false, isAnyType=false, isDefault=false, simpleType=false, primitiveType=false, isMap=false, isOptional=false, isArray=false, isBinary=false, isFile=false, schema=class Schema {
    type: null
    format: null
    $ref: #/components/schemas/foo_200_response
    description: null
    title: null
    multipleOf: null
    maximum: null
    exclusiveMaximum: null
    minimum: null
    exclusiveMinimum: null
    maxLength: null
    minLength: null
    pattern: null
    maxItems: null
    minItems: null
    uniqueItems: null
    maxProperties: null
    minProperties: null
    required: null
    not: null
    properties: null
    additionalProperties: null
    nullable: null
    readOnly: null
    writeOnly: null
    example: null
    externalDocs: null
    deprecated: null
    discriminator: null
    xml: null
}, jsonSchema='{
  "description" : "Successful operation",
  "content" : {
    "application/json" : {
      "schema" : {
        "$ref" : "#/components/schemas/foo_200_response"
      }
    }
  }
}', vendorExtensions={}, maxProperties=null, minProperties=null, uniqueItems=false, uniqueItemsBoolean=null, maxItems=null, minItems=null, maxLength=null, minLength=null, exclusiveMinimum=false, exclusiveMaximum=false, minimum='null', maximum='null', pattern='null', multipleOf='null', items='null', additionalProperties='null', vars='[]', requiredVars='[]', isNull='false, isVoid='false, hasValidation='false, getAdditionalPropertiesIsAnyType=false, getHasVars=false, getHasRequired=false, getHasDiscriminatorWithNonEmptyMapping=false, composedSchemas=null, hasMultipleTypes=false, responseHeaders=[], content={application/json=CodegenMediaType{schema=CodegenProperty{openApiType='Foo200Response', baseName='SchemaFor200ResponseBodyApplicationJson', complexType='Foo200Response', getter='getSchemaFor200ResponseBodyApplicationJson', setter='setSchemaFor200ResponseBodyApplicationJson', description='null', dataType='AMinimalOpenAPIExample.Model.Foo200Response.t', datatypeWithEnum='AMinimalOpenAPIExample.Model.Foo200Response.t', dataFormat='null', name='SchemaFor200ResponseBodyApplicationJson', min='null', max='null', defaultValue='null', defaultValueWithParam=' = data.SchemaFor200ResponseBodyApplicationJson;', baseType='Foo200Response', containerType='null', containerTypeMapped='null', title='null', unescapedDescription='null', maxLength=null, minLength=null, pattern='null', example='null', jsonSchema='{
  "$ref" : "#/components/schemas/foo_200_response"
}', minimum='null', maximum='null', exclusiveMinimum=false, exclusiveMaximum=false, required=false, deprecated=false, hasMoreNonReadOnly=false, isPrimitiveType=false, isModel=true, isContainer=false, isString=false, isNumeric=false, isInteger=false, isShort=false, isLong=false, isUnboundedInteger=false, isNumber=false, isFloat=false, isDouble=false, isDecimal=false, isByteArray=false, isBinary=false, isFile=false, isBoolean=false, isDate=false, isDateTime=false, isUuid=false, isUri=false, isEmail=false, isPassword=false, isFreeFormObject=false, isArray=false, isMap=false, isOptional=false, isEnum=false, isInnerEnum=false, isEnumRef=false, isAnyType=false, isReadOnly=false, isWriteOnly=false, isNullable=false, isSelfReference=false, isCircularReference=false, isDiscriminator=false, isNew=false, isOverridden=null, _enum=null, allowableValues=null, items=null, additionalProperties=null, vars=[], requiredVars=[], mostInnerItems=null, vendorExtensions={}, hasValidation=false, isInherited=false, discriminatorValue='null', nameInCamelCase='schemaFor200ResponseBodyApplicationJson', nameInPascalCase='SchemaFor200ResponseBodyApplicationJson', nameInSnakeCase='SCHEMA_FOR200_RESPONSE_BODY_APPLICATION_JSON', enumName='null', maxItems=null, minItems=null, maxProperties=null, minProperties=null, uniqueItems=false, uniqueItemsBoolean=null, multipleOf=null, isXmlAttribute=false, xmlPrefix='null', xmlName='null', xmlNamespace='null', isXmlWrapped=false, isNull=false, isVoid=false, getAdditionalPropertiesIsAnyType=false, getHasVars=false, getHasRequired=false, getHasDiscriminatorWithNonEmptyMapping=false, composedSchemas=null, hasMultipleTypes=false, hasSanitizedName=false, requiredVarsMap=null, ref=#/components/schemas/foo_200_response, schemaIsFromAdditionalProperties=false, isBooleanSchemaTrue=false, isBooleanSchemaFalse=false, format=null, dependentRequired=null, contains=null}, encoding=null, vendorExtensions={}}}, requiredVarsMap=null, ref=null, schemaIsFromAdditionalProperties=false}

CodegenResponse{headers=[], code='200', is1xx='false', is2xx='false', is3xx='false', is4xx='false', is5xx='false', message='Successful operation', examples=null, dataType='any()', baseType='Foo', containerType='null', containerTypeMapped='null', hasHeaders=false, isString=false, isNumeric=false, isInteger=false, isShort=false, isLong=false, isUnboundedInteger=false, isNumber=false, isFloat=false, isDouble=false, isDecimal=false, isByteArray=false, isBoolean=false, isDate=false, isDateTime=false, isUuid=false, isEmail=false, isPassword=false, isModel=true, isFreeFormObject=false, isAnyType=false, isDefault=false, simpleType=false, primitiveType=false, isMap=false, isOptional=false, isArray=false, isBinary=false, isFile=false, schema=class ComposedSchema {
    class Schema {
        type: null
        format: null
        $ref: null
        description: null
        title: null
        multipleOf: null
        maximum: null
        exclusiveMaximum: null
        minimum: null
        exclusiveMinimum: null
        maxLength: null
        minLength: null
        pattern: null
        maxItems: null
        minItems: null
        uniqueItems: null
        maxProperties: null
        minProperties: null
        required: null
        not: null
        properties: null
        additionalProperties: null
        nullable: null
        readOnly: null
        writeOnly: null
        example: null
        externalDocs: null
        deprecated: null
        discriminator: null
        xml: null
    }
}, jsonSchema='{
  "description" : "Successful operation",
  "content" : {
    "application/json" : {
      "schema" : {
        "allOf" : [ {
          "$ref" : "#/components/schemas/Foo"
        } ]
      }
    }
  }
}', vendorExtensions={}, maxProperties=null, minProperties=null, uniqueItems=false, uniqueItemsBoolean=null, maxItems=null, minItems=null, maxLength=null, minLength=null, exclusiveMinimum=false, exclusiveMaximum=false, minimum='null', maximum='null', pattern='null', multipleOf='null', items='null', additionalProperties='null', vars='[]', requiredVars='[]', isNull='false, isVoid='false, hasValidation='false, getAdditionalPropertiesIsAnyType=false, getHasVars=false, getHasRequired=false, getHasDiscriminatorWithNonEmptyMapping=false, composedSchemas=null, hasMultipleTypes=false, responseHeaders=[], content={application/json=CodegenMediaType{schema=CodegenProperty{openApiType='Foo', baseName='SchemaFor200ResponseBodyApplicationJson', complexType='Foo', getter='getSchemaFor200ResponseBodyApplicationJson', setter='setSchemaFor200ResponseBodyApplicationJson', description='null', dataType='AMinimalOpenAPIExample.Model.Foo.t', datatypeWithEnum='AMinimalOpenAPIExample.Model.Foo.t', dataFormat='null', name='SchemaFor200ResponseBodyApplicationJson', min='null', max='null', defaultValue='null', defaultValueWithParam=' = data.SchemaFor200ResponseBodyApplicationJson;', baseType='Foo', containerType='null', containerTypeMapped='null', title='null', unescapedDescription='null', maxLength=null, minLength=null, pattern='null', example='null', jsonSchema='{
  "$ref" : "#/components/schemas/Foo"
}', minimum='null', maximum='null', exclusiveMinimum=false, exclusiveMaximum=false, required=false, deprecated=false, hasMoreNonReadOnly=false, isPrimitiveType=false, isModel=true, isContainer=false, isString=false, isNumeric=false, isInteger=false, isShort=false, isLong=false, isUnboundedInteger=false, isNumber=false, isFloat=false, isDouble=false, isDecimal=false, isByteArray=false, isBinary=false, isFile=false, isBoolean=false, isDate=false, isDateTime=false, isUuid=false, isUri=false, isEmail=false, isPassword=false, isFreeFormObject=false, isArray=false, isMap=false, isOptional=false, isEnum=false, isInnerEnum=false, isEnumRef=false, isAnyType=false, isReadOnly=false, isWriteOnly=false, isNullable=false, isSelfReference=false, isCircularReference=false, isDiscriminator=false, isNew=false, isOverridden=null, _enum=null, allowableValues=null, items=null, additionalProperties=null, vars=[], requiredVars=[], mostInnerItems=null, vendorExtensions={}, hasValidation=false, isInherited=false, discriminatorValue='null', nameInCamelCase='schemaFor200ResponseBodyApplicationJson', nameInPascalCase='SchemaFor200ResponseBodyApplicationJson', nameInSnakeCase='SCHEMA_FOR200_RESPONSE_BODY_APPLICATION_JSON', enumName='null', maxItems=null, minItems=null, maxProperties=null, minProperties=null, uniqueItems=false, uniqueItemsBoolean=null, multipleOf=null, isXmlAttribute=false, xmlPrefix='null', xmlName='null', xmlNamespace='null', isXmlWrapped=false, isNull=false, isVoid=false, getAdditionalPropertiesIsAnyType=false, getHasVars=false, getHasRequired=false, getHasDiscriminatorWithNonEmptyMapping=false, composedSchemas=null, hasMultipleTypes=false, hasSanitizedName=false, requiredVarsMap=null, ref=#/components/schemas/Foo, schemaIsFromAdditionalProperties=false, isBooleanSchemaTrue=false, isBooleanSchemaFalse=false, format=null, dependentRequired=null, contains=null}, encoding=null, vendorExtensions={}}}, requiredVarsMap=null, ref=null, schemaIsFromAdditionalProperties=false}