How to handle async adapters?

[s1n7ax]

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?

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]

You can use the nio library that is bundled with neotest to wrap callback style functions

local nio = require("nio")

local executeCommand = nio.wrap(jdtls.executeCommand, 2)

adapter.is_test_file = function(file_path)
  local uri = vim.uri_from_fname(file_path)
  local err, is_test_file = executeCommand({
    command = "java.project.isTestFile",
    arguments = { uri },
  })
  assert(err, "could not check the file")
  return is_test_file
end

[rcarriga]

What should build_spec return? Is it a dap laucher config?

Here are the interface and types. For the dap strategy, you need to pass a dap table in the context which is a launcher config. Here is what neotest-python returns

[s1n7ax]

@rcarriga nvim-java got a co-routine library https://github.com/nvim-java/lua-async-await. Seems like the one you are using and the one I'm using is not compatible.

I tried request_sync in vim.lsp.client too. It doesn't work either.

When I do this,

function neotest.Adapter.is_test_file(file_path)
  if
    file_path
    == "/home/s1n7ax/Workspace/demo/src/test/java/com/example/demo/DemoApplicationTests.java"
  then
    return true
  end

  return false
end

discover_positions function is being called for DemoApplicationTests.java file.

filter_dir src/test/java/com/example/example
filter_dir src/main/java/com/example/example
filter_dir bin/test/com/example/demo/demo
filter_dir bin/main/com/example/demo/demo
filter_dir src/test/java/com/example/demo/demo
filter_dir src/main/java/com/example/demo/demo
discover_position/home/s1n7ax/Workspace/demo/src/test/java/com/example/demo/DemoApplicationTests.java

However, when following logic is used,

local function execute_command(cmd_info, timeout, buffer)
  timeout = timeout and timeout or 5000
  buffer = buffer and buffer or 0

  return jdtls().request_sync("workspace/executeCommand", cmd_info, timeout, buffer)
end

function neotest.Adapter.is_test_file(file_path)
  vim.print("is test file check: " .. file_path)

  local response = execute_command({
    command = "java.project.isTestFile",
    arguments = { vim.uri_from_fname(file_path) },
  })

  if response.err then
    error(response.err.message)
  end

  vim.print(response.result)
  return response.result
end

Output looks as follows. It's defiantly blocking and value is being returned but discover_positions never called.

filter_dir bin/test/com/example/demo/demo
filter_dir bin/main/com/example/demo/demo
filter_dir src/test/java/com/example/demo/demo
filter_dir src/main/java/com/example/demo/demo
is test file check: /home/s1n7ax/Workspace/demo/gradlew
is test file check: /home/s1n7ax/Workspace/demo/src/test/java/com/example/demo/DemoApplicationTests.java
true
is test file check: /home/s1n7ax/Workspace/demo/src/test/java/com/example/demo/DemoApplicationTests.java
true
is test file check: /home/s1n7ax/Workspace/demo/src/test/java/com/example/demo/DemoApplicationTests.java
true

[rcarriga]

I can't see how your async library would be interfering but since this is only partial code, it's impossible to rule out. From the snippets you've provided so far, there is no involvement of your async library right? (Not too sure what jdtls is)

Without a full reproduction example, there's not much I can do to help here unfortunately. You could try adding some log lines to the client file in neotest, and check the log. Here is where the is_test_file function is used.

[s1n7ax]

No, I first tried to use my async library and yours both at the same time. It did not work. That's why I have tried above example which did not work either

[s1n7ax]

THIS IS THE implementation with my co-routine library. NOT the above example.

I pushed implementation here. This wont work without https://github.com/nvim-java-core dependency.
https://github.com/nvim-java/neotest-jdtls

I have this to call jdtls and get the is test status from server. I have made it a callback style so I can wrap it using your library
https://github.com/nvim-java/neotest-jdtls/blob/0fca10b753d16d33ff8b06b34cf9c4b0a257bd45/lua/neotest-jdtls/helper.lua?plain=1#L16-L28

Here is how I've wrapped and used it
https://github.com/nvim-java/neotest-jdtls/blob/0fca10b753d16d33ff8b06b34cf9c4b0a257bd45/lua/neotest-jdtls/init.lua?plain=1#L57-L67

Here is the output. As you can see from the logs, request is sent to get is test file check and response was received successfully.

is test: /home/s1n7ax/Workspace/demo/src/test/java/com/example/demo/DemoApplicationTests.java
*************************
{
  arguments = { "file:///home/s1n7ax/Workspace/demo/src/test/java/com/example/demo/DemoApplicationTests.java" },
  command = "java.project.isTestFile"
}
<function 1>
>>>>>>>>>>>>>>>>>>>>>>>>>
java.project.isTestFile success! response: 
true
res: 
true
Error executing vim.schedule lua callback: ...x/Workspace/nvim-java-core/lua/java-core/utils/async.lua:41: unhandled error ...n7ax/.local/share/nvim/lazy/nvim-nio/lua/nio/control.lua:133: Future already set
stack traceback:
	[C]: in function 'error'
	...x/Workspace/nvim-java-core/lua/java-core/utils/async.lua:41: in function 'callback'
	...nvim-java-core/lua/java-core/ls/clients/jdtls-client.lua:51: in function 'handler'
	...eovim-unwrapped-0.9.4/share/nvim/runtime/lua/vim/lsp.lua:1393: in function ''
	vim/_editor.lua: in function <vim/_editor.lua:0>