export-jdl always uses app.jdl as filename

[ruddell]

Overview of the issue

jhipster export-jdl always uses app.jdl as filename, hardcoded here. There's a related test in generator-jhipster that only passes since it was updated to use app.jdl

We should either update the docs to say it does not take an argument, or write the exported JDL to the argument.

Reproduce the error

Generate a project, then run: jhipster export-jdl test.jdl

It exports the JDL to app.jdl, ignoring test.jdl

Related Issues

https://github.com/jhipster/generator-jhipster/pull/10044 Fix jdl export https://github.com/jhipster/jhipster-core/pull/343 Implemented the single & multi app export

JHipster Version(s)

Started in v6.2.0+ v6.1.2 works as expected

JHipster configuration

.yo-rc.json file

{
  "generator-jhipster": {
    "promptValues": {
      "packageName": "com.mycompany.myapp",
      "nativeLanguage": "en"
    },
    "jhipsterVersion": "6.3.0",
    "applicationType": "monolith",
    "baseName": "mono",
    "packageName": "com.mycompany.myapp",
    "packageFolder": "com/mycompany/myapp",
    "serverPort": "8080",
    "authenticationType": "jwt",
    "cacheProvider": "ehcache",
    "enableHibernateCache": true,
    "websocket": false,
    "databaseType": "sql",
    "devDatabaseType": "h2Disk",
    "prodDatabaseType": "mysql",
    "searchEngine": false,
    "messageBroker": false,
    "serviceDiscoveryType": false,
    "buildTool": "maven",
    "enableSwaggerCodegen": false,
    "jwtSecretKey": "bXktc2VjcmV0LXRva2VuLXRvLWNoYW5nZS1pbi1wcm9kdWN0aW9uLWFuZC10by1rZWVwLWluLWEtc2VjdXJlLXBsYWNl",
    "clientFramework": "angularX",
    "useSass": true,
    "clientPackageManager": "npm",
    "testFrameworks": [],
    "jhiPrefix": "jhi",
    "enableTranslation": true,
    "nativeLanguage": "en",
    "languages": [
      "en"
    ],
    "embeddableLaunchScript": false,
    "clientTheme": "none",
    "entitySuffix": "",
    "dtoSuffix": "DTO",
    "otherModules": [],
    "blueprints": []
  }
}

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