[BUG] Error when working with npm workspaces

🐛 Bug Report:

Describe the bug

The generator crashes with the [error] Required option '-i' is missing error when running with different cwd.

Steps to Reproduce

Steps to reproduce the behavior:

1. Create a npm project with two workspaces: packages/client and packages/server (server probably isn't even necessary)
2. Save a spec in packages/openapi.yaml
3. Reference it in packages/client/openapitools.json via "inputSpec": "../openapi.yaml"
4. Add a script in client: "openapi": "openapi-generator-cli generate" and run it
   • It works ✔️
5. Add a script in root "openapi": "npm run openapi --workspaces --if-present" and run it
   • See error ❌
   • Generates a openapitools.json in the root directory

Failing workaround

I created a packages/client/openapi.js script and let it run in client via "openapi": "node openapi.js" , but this also fails in the same way.

// try forcing the cwd to the client directory (works when checking with pwd command)
const child = require('child_process').exec('openapi-generator-cli generate', { cwd: __dirname });
child.stdout.pipe(process.stdout);
child.stderr.pipe(process.stderr);
child.on('exit', code => process.exit(code));

Expected behavior

I expect the generator to always find the file.

Operation System:

• OS: Windows
• Version 10

Package System:

• npm v8.3.0