Swagger-faker pattern incorrectly applies slashes around regex

[editedredx]

What version of kubb is running?

kubb/2.6.5 win32-x64 node-v18.14.0

What platform is your computer?

Windows

What version of external packages are you using(@tanstack-query, MSW, React, Vue, ...)

"@faker-js/faker": "^8.4.1",     "@kubb/cli": "^2.6.5",     "@kubb/core": "^2.6.5",     "@kubb/swagger": "^2.6.5",     "@kubb/swagger-client": "^2.6.5",     "@kubb/swagger-tanstack-query": "^2.6.5",     "@kubb/swagger-ts": "^2.6.5",     "@mswjs/http-middleware": "^0.9.2",     "@tanstack/react-query": "^5.24.1",     "axios": "^1.6.7",     "msw": "^2.2.2",     "ts-node": "^10.9.2",     "@kubb/swagger-faker": "^2.6.5",     "@kubb/swagger-msw": "^2.6.5"

What steps can reproduce the bug?

When using the following simple config to create MSW mocks with the spec below:

import { defineConfig } from "@kubb/core";
import createSwagger from "@kubb/swagger";
import createSwaggerFaker from "@kubb/swagger-faker";
import createSwaggerMsw from "@kubb/swagger-msw";
import createSwaggerTS from "@kubb/swagger-ts";

export default defineConfig({
  root: ".",
  input: {
    path: "./test-spec.yaml",
  },
  output: {
    path: "./dist",
  },
  plugins: [
    createSwagger({ output: false }),
    createSwaggerTS({}),
    createSwaggerFaker({}),
    createSwaggerMsw({
      output: {
        path: "./mocks",
      },
    }),
  ],
});

This will create the mocks for an MSW server, if you start one up and visit http://localhost:9090/test you get something like this:

{
    "nationalityCode": "/^ZF$/"
}

How often does this bug happen?

Every time

What is the expected behavior?

I would expect the regex characters not to appear in the mocked output.

{
    "nationalityCode": "ZF"
}

Swagger/OpenAPI file?

openapi: 3.0.0
info:
  title: test API
  version: 1.0.0

paths:
  /test:
    get:
      operationId: getTest
      responses:
        "200":
          description: Successful operation
          content:
            application/json:
              schema:
                type: object
                properties:
                  nationalityCode:
                    type: string
                    pattern: "^[A-Z]{2}$"

Additional information

I noticed the slashes are wrapped around the value by this lib which I'm not sure why (https://github.com/kubb-project/kubb/blob/main/packages/swagger-faker/src/FakerGenerator.ts#L334).

Could there be a configurable way to clean up patterns before they are placed inside the mock? For this example I would like to remove the ^ and $ since Faker will just leave those in place. They do make sense in the source yaml so I wouldn't want to change that.

[editedredx]

While digging in the source code I found the undocumented feature of transforming the schema via de configuration and created the following workaround:

import { defineConfig } from "@kubb/core";
import createSwagger from "@kubb/swagger";
import createSwaggerFaker from "@kubb/swagger-faker";
import createSwaggerMsw from "@kubb/swagger-msw";
import createSwaggerTS from "@kubb/swagger-ts";

export default defineConfig({
  root: ".",
  input: {
    path: "./test-spec.yaml",
  },
  output: {
    path: "./dist",
  },
  plugins: [
    createSwagger({ output: false }),
    createSwaggerTS({}),
    createSwaggerFaker({
      transformers: {
        schema(schema) {
          if (
            schema.type &&
            schema.pattern &&
            typeof schema.pattern === "string"
          ) {
            return [
              {
                keyword: "matches",
                args: schema.pattern.replace(/(^\^)|(\$$)/g, ""),
              },
            ];
          }
          return undefined;
        },
      },
    }),
    createSwaggerMsw({
      output: {
        path: "./mocks",
      },
    }),
  ],
});

While this does create a workaround I think at least the wrapping of slashes should not happen.