[BUG][typescript-angular] Schemas with allOf and Schemas using required and additionalProperties fails to generate models

Bug Report Checklist

• Have you provided a full/minimal spec to reproduce the issue?
• Have you validated the input using an OpenAPI validator?
• 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

I use Typescript-Angular generator. I have a specific use case of OpenApi that doesn't generate models

openapi-generator version

• cli 2.23
• generator 7.15

OpenAPI declaration file content or url

{
  "openapi": "3.1.0",
  "info": {
    "title": "Demo bug allOf",
    "version": "1.0.0"
  },
  "servers": [
    {
      "url": "http://localhost:3000"
    }
  ],
  "security": [],
  "paths": {
    "/v1/demo": {
      "get": {
        "operationId": "getDemoV1",
        "summary": "Get demo",
        "responses": {
          "200": {
            "description": "successful operation",
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/DemoV1"
                }
              }
            }
          },
          "400": {
            "description": "bad request"
          }
        }
      }
    }
  },
  "components": {
    "schemas": {
      "DemoV1": {
        "type": "object",
        "additionalProperties": false,
        "required": [
          "demoId",
          "status"
        ],
        "properties": {
          "demoId": {
            "type": "string"
          },
          "status": {
            "type": "string",
            "enum": [
              "new",
              "in_progress",
              "completed"
            ]
          },
          "extra": {
            "type": "object",
            "description": "extra data",
            "required": [
              "data"
            ],
            "additionalProperties": false,
            "properties": {
              "data": {
                "type": "string"
              }
            }
          }
        },
        "allOf": [
          {
            "if": {
              "properties": {
                "status": {
                  "enum": [
                    "new"
                  ]
                }
              }
            },
            "then": {
              "required": [
                "extra"
              ]
            }
          }
        ]
      }
    }
  }
}

Generation Details

OpenApi Generator Config

{
  "additionalProperties": {
    "disallowAdditionalPropertiesIfNotPresent": false,
    "fileNaming": "kebab-case",
    "enumPropertyNaming": "camelCase",
    "modelPropertyNaming": "original",
    "queryParamObjectFormat": "json",
    "modelFileSuffix": "-dto.model",
    "modelSuffix": "Dto",
    "serviceFileSuffix": ".gateway",
    "serviceSuffix": "Gateway"
  }
}

OpenApi Tools

{
  "$schema": "./node_modules/@openapitools/openapi-generator-cli/config.schema.json",
  "spaces": 2,
  "generator-cli": {
    "version": "7.15.0"
  }
}

Package.json to reproduce problem

{
    "name": "demo-bug-allof",
    "version": "0.0.0",
    "scripts": {
      "generate:gateway": "openapi-generator-cli generate -g typescript-angular --global-property skipFormModel=false -i ./openapi.json -o ./gateway -c ./openapi-config.json"
    },
    "devDependencies": {
      "@openapitools/openapi-generator-cli": "^2.18.4",
      "ts-node": "^10.9.2",
      "typescript": "~5.7.2"
    }
}
  

Steps to reproduce

• npm install where you put the package.json
• run npm generate:gateway

Open gateway/models/models.ts : it's empty

• remove properties required and additionalProperties from object 'extra' and rerun the previous steps

Open gateway/models/models.ts : it references 2 other DTO files

Related issues/PRs

Suggest a fix

Start with the minimal OpenAPI declaration, openapi-config.json, and the npm generation command in package.json. Inspect generated gateway/models/models.ts and compare the output with and without required and additionalProperties on extra. Done means the typescript-angular generator produces the expected DTO model references for the reproduced schema.