[BUG][dart2] Description

Created by: dayofr

Bug Report Checklist

• Have you provided a full/minimal spec to reproduce the issue?
• Have you validated the input using an OpenAPI validator (example)?
• What's the version of OpenAPI Generator used?
• Have you search for related issues/PRs?
• What's the actual output vs expected output?
• [Optional] Bounty to sponsor the fix

Description

Using the dart generator and publishing the generated content to pub.dev we can see some health suggestions regarding the effective dart style: https://pub.dev/packages/gitea_openapi#-analysis-tab-

It would be best to follow the dart style.

openapi-generator version

4.2.3

OpenAPI declaration file content or url

Command line used for generation

java -jar .\openapi-generator-cli-4.2.3.jar generate -g dart -i https://try.gitea.io/swagger.v1.json -o C:\dev\gitea2 --additional-properties pubName=gitea

Steps to reproduce

run generate command above and check output in supporting files

Related issues/PRs

Non found

Suggest a fix

Update templates to add curly braces for all flow control structures and don't explicitly initialize variables to null.

Could you guide me on how to update the template?