Thanks to the contribution by "ircecho" (https://github.com/OpenAPITools/openapi-generator/pull/2894), the Dart API client generator in the OpenAPI Generator project now supports Dart 2.3 which was released recently. Here are a few steps to generate Dart API client given an OpenAPI specification file:
1. Download the Java JAR (https://oss.sonatype.org/content/repositories/snapshots/org/...)
2. Rename the JAR as "openapi-generator-cli.jar"
3. Run the following command to generate a Dart API client for the Petstore API (https://raw.githubusercontent.com/OpenAPITools/openapi-gener...):
Mac/Linux:
- java -jar openapi-generator-cli.jar generate -g dart -i https://raw.githubusercontent.com/OpenAPITools/openapi-gener... -o /var/tmp/dart-api-client/
Windows:
- java -jar openapi-generator-cli.jar generate -g dart -i https://raw.githubusercontent.com/OpenAPITools/openapi-gener... -o C:\tmp\dart-api-client
Please give it a try and let us know if you've any feedback.