Default values override "required" state in output types

[dave-addition]

Description

Generated types don't allow undefined inputs on fields with default values, even if they're not part of the "required" fields array.

Name	Version
openapi-typescript	7.0.2
Node.js	v20.12.2
OS + version	macOS 14.5

Reproduction

Create a package.json like:

{
  "name": "test-scripts",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "start": "http-server -p 4000",
    "generate": "tsx ./generate-types.ts > ./openapi-output.ts"
  },
  "dependencies": {
    "openapi-typescript": "7.0.2",
    "tsx": "4.7.1",
    "typescript": "5.4.5"
  },
  "devDependencies": {
    "http-server": "14.1.1"
  },
  "author": "",
  "license": "ISC"
}

Add a docs-json file with:

{
  "openapi": "3.0.0",
  "security": [
    {
      "bearer": []
    }
  ],
  "paths": {
    "/do/the/thing": {
      "post": {
        "operationId": "Controller_method",
        "summary": "Do something.",
        "parameters": [],
        "requestBody": {
          "required": true,
          "content": {
            "application/json": {
              "schema": {
                "$ref": "#/components/schemas/MyInputType"
              }
            }
          }
        },
        "responses": {
          "200": {
            "description": "Did the thing."
          },
          "400": {
            "description": "Bad request."
          }
        }
      }
    }
  },
  "info": {
    "title": "Test API",
    "license": {
      "name": "MIT",
      "url": "https://opensource.org/license/mit"
    },
    "description": "",
    "version": "1.0",
    "contact": {}
  },
  "tags": [],
  "servers": [
    {
      "url": "https://some.site.com/v1"
    }
  ],
  "components": {
    "securitySchemes": {
      "bearer": {
        "scheme": "bearer",
        "bearerFormat": "JWT",
        "type": "http"
      }
    },
    "schemas": {
      "MyInputType": {
        "type": "object",
        "properties": {
          "requiredField": {
            "type": "string"
          },
          "optionalField": {
            "type": "string"
          },
          "optionalFieldWithDefault": {
            "type": "string",
            "default": "foo"
          }
        },
        "required": [
          "requiredField"
        ]
      }
    }
  }
}

and a generate-types.ts file with:

import openapiTS from "openapi-typescript";
import ts, { EmitHint } from "typescript";

openapiTS("http://127.0.0.1:4000/docs-json", {
  alphabetize: true,
}).then((output) => {
  const outFile = ts.createSourceFile("API.ts", "", ts.ScriptTarget.Latest);
  const printer = ts.createPrinter({ newLine: ts.NewLineKind.LineFeed });
  output.forEach((typeNode) => {
    console.log(printer.printNode(EmitHint.Unspecified, typeNode, outFile));
  });
});

Run yarn start in one terminal window and yarn generate in another. This creates an openapi-output.ts file.

Expected result

I expect a schema which looks like this:

        MyInputType: {
            optionalField?: string;
            /** @default foo */
            optionalFieldWithDefault?: string;
            requiredField: string;
        };

But this is what the script outputs:

        MyInputType: {
            optionalField?: string;
            /** @default foo */
            optionalFieldWithDefault: string;
            requiredField: string;
        };

I'm surprised by this because the "required" array is part of the offical JSON schema spec, whereas the default value is (to the best of my knowledge) not. The closest thing I could find to documentation was here, where the docs say:

Unless stated otherwise, the property definitions follow those of JSON Schema and do not add any additional semantics.

So I would expect the ? types to be determined by "required" fields only.

Checklist

• My OpenAPI schema passes the Redocly validator (npx @redocly/cli@latest lint)
• I’m willing to open a PR (see CONTRIBUTING.md) (I may be open to this, but don't want to commit to it as I'm not familiar with this project and unsure how tough it would be)

[phk422]

@dave-addition You can refer to this pr：#1746 (comment)

[dave-addition]

Ah! Yeah setting defaultNonNullable to false does indeed fix this. For what it's worth I find this default behavior a bit surprising... but the option is clear and well documented, so works for me!

Thanks to you and all the other contributors for all your hard work on this project.