How to handle async adapters?

[s1n7ax]

Discussed in https://github.com/nvim-neotest/neotest/discussions/322

^{Originally posted by **s1n7ax** November 19, 2023} I'm working on https://github.com/nvim-java/nvim-java. So far, I have created only two APIs to run tests. - `run_current_test_class` - `debug_current_test_class` Both these are ran using `nvim-dap` & test discovery is done by communicating to `jdtls` language server. However, I would like to have an adapter so I can get all the neotest features come with it. However, I don't really understand how to do asynchronous stuff from the given adapter interface. I can see that you have the `@async` annotation in each method, however, there is no callback function passed to any APIs. So I would like to get help on - doing async stuff For instance, there is a language sever command for checking if the given file is a test or not in jdtls. It's `java.project.isTestFile`. However calling this has to be done asynchronously. So my adapter function should look like this with a callback function. But looking at the interface there is not? So how should this be handled? ```lua adapter.is_test_file = function(file_path, callback) jdtls.executeCommand({ command = 'java.project.isTestFile', arguments = { uri }, }, function(err, is_test_file) assert(err, 'could not check the file') callback(is_test_file) end) end ``` - What should `build_spec` return? Is it a dap laucher config?

[rcarriga]

Closing and continuing in discussion linked