Use something shortenCommandLine

[rcasia]

Hi!

I'm working on a large Java project on Neovim Windows, and I encountered many problems with jdtls and java-debug until I found out about the

shortenCommandLine: 'argfile'

argument, set either in the .vscode/launch.json or in the jdtls configuration (see this discussion).

I am experimenting with neotest-java for better test handling within Neovim, but I'm getting the usual issues that happens when I try to run or debug without the shortenCommandLine argument set to 'argfile': lockups, timeouts and no output.

My configuration for neotest-java is the same as the LazyVim setup described in the README.

OS: Windows 11 Pro (23H2)
Neovim: 0.11
JDTLS: 1.43
java-test: 0.43
LazyVim: 14.6.0

Originally posted by @erikson84 in #170

[rcasia]

Any chance that you could provide some logs? @erikson84

[erikson84]

My main issue is that Neovim hangs because the huge classPath in my project ends up raising a timeout exception. Here are some DAP logs (with classPath removed for brevity; neotest-java.log file does not log any relevant information):

[DEBUG] 2025-03-13 13:27:43 dap/session.lua:1872	"request"	{
  arguments = {
    args = "-version 3 -port 54581 -testLoaderClass org.eclipse.jdt.internal.junit5.runner.JUnit5TestLoader -loaderpluginname org.eclipse.jdt.junit5.runtime -test testClass:testNull",
    classPaths = { [HUGE, 33.000+chars classPath, removed for brevity] },
    cwd = "C:\\Users\\...",
    javaExec = "C:\\Users\...",
    mainClass = "org.eclipse.jdt.internal.junit.runner.RemoteTestRunner",
    modulePaths = {},
    name = "testClass#testNull()",
    noDebug = false,
    projectName = "project_name",
    request = "launch",
    type = "java",
    vmArgs = "-ea"
  },
  command = "launch",
  seq = 2,
  type = "request"
}
[DEBUG] 2025-03-13 13:27:43 dap/session.lua:1068	2	{
  arguments = {
    args = { "C:\\Users\\...\\java.exe", "-agentlib:jdwp=transport=dt_socket,server=n,suspend=y,address=localhost:54583", "-ea", "-cp", "[HUGE, 33.000+chars classPath, removed for brevity]", "org.eclipse.jdt.internal.junit.runner.RemoteTestRunner", "-version", "3", "-port", "54581", "-testLoaderClass", "org.eclipse.jdt.internal.junit5.runner.JUnit5TestLoader", "-loaderpluginname", "org.eclipse.jdt.junit5.runtime", "-test", "testClass:testNull" },
    cwd = "C:\\Users\\...",
    kind = "integrated",
    title = "Debug: RemoteTestRunner"
  },
  command = "runInTerminal",
  seq = 2,
  type = "request"
}
[DEBUG] 2025-03-13 13:27:43 dap/session.lua:230	"run_in_terminal"	{
  args = { "C:\\Users\\...\\java.exe", "-agentlib:jdwp=transport=dt_socket,server=n,suspend=y,address=localhost:54583", "-ea", "-cp", "[HUGE, 33.000+chars classPath, removed for brevity]", "org.eclipse.jdt.internal.junit.runner.RemoteTestRunner", "-version", "3", "-port", "54581", "-testLoaderClass", "org.eclipse.jdt.internal.junit5.runner.JUnit5TestLoader", "-loaderpluginname", "org.eclipse.jdt.junit5.runtime", "-test", "testClass:testNull" },
  cwd = "C:\\Users\\...",
  kind = "integrated",
  title = "Debug: RemoteTestRunner"
}
[DEBUG] 2025-03-13 13:28:25 dap/session.lua:1902	"response"	{
  body = {
    processId = 16016
  },
  command = "runInTerminal",
  request_seq = 2,
  seq = 3,
  success = true,
  type = "response"
}
[DEBUG] 2025-03-13 13:28:25 dap/session.lua:1068	2	{
  body = {
    error = {
      format = "Failed to launch debuggee in terminal. Reason: Failed to launch debuggee in terminal. Reason: java.util.concurrent.TimeoutException: timeout",
      id = 1014
    }
  },
  command = "launch",
  message = "Failed to launch debuggee in terminal. Reason: Failed to launch debuggee in terminal. Reason: java.util.concurrent.TimeoutException: timeout",
  request_seq = 2,
  seq = 3,
  success = false,
  type = "response"
}

[DEBUG] 2025-03-13 14:22:19 dap/session.lua:1464	"Connecting to debug adapter"	{
  enrich_config = <function 1>,
  host = "127.0.0.1",
  port = 54557,
  type = "server"
}

If I were able to pass the shortenCommandLine: 'argfile' option in the first DAP request, I think this wouldn't happen, because I was getting the same problem while debugging my Java project and this options solved it for me.

[rcasia]

I'm not able to reproduce this issue, but per what was said on mfussenegger/nvim-jdtls#674 (comment) and analyzing nvim-jdtls and neotest code, the solution should be just modifying this:

neotest-java/lua/neotest-java/core/spec_builder/init.lua

Lines 93 to 98 in 1404de7

	strategy = {
	type = "java",
	request = "attach",
	name = ("neotest-java (on port %s)"):format(port),
	port = port,
	},

By adding this line:

  shortenCommandLine = "argfile",

Can you give it a try?

[rcasia]

[DEBUG] 2025-03-13 13:27:43 dap/session.lua:1872 "request" {
arguments = {
args = "-version 3 -port 54581 -testLoaderClass org.eclipse.jdt.internal.junit5.runner.JUnit5TestLoader -loaderpluginname org.eclipse.jdt.junit5.runtime -test testClass:testNull",
classPaths = { [HUGE, 33.000+chars classPath, removed for brevity] },
cwd = "C:\Users\...",
javaExec = "C:\Users...",
mainClass = "org.eclipse.jdt.internal.junit.runner.RemoteTestRunner",
modulePaths = {},
name = "testClass#testNull()",
noDebug = false,
projectName = "project_name",
request = "launch",
type = "java",
vmArgs = "-ea"
},
command = "launch",
seq = 2,
type = "request"
}

Also, the shared logs do not match with the neotest-java strategy fields:

 request = "attach", 
 name = ("neotest-java (on port %s)"):format(port), 

Make sure require("neotest").run.run({ strategy = "dap" }) is being invoked.

[erikson84]

I'm still getting hangups with DAP, even after adding the 'shortenCommandLine', but I was able to get normal testing running. I had to make some changes to the source code for make the generated JUnit call compatible with PowerShell, I will detail the changes soon.

[erikson84]

I'm using my personal computer now and trying with the basic maven-demo project included in neotest-java. I was able to run the tests with the following edits:

neotest-java/lua/neotest-java/command/junit_command_builder.lua

Lines 93 to 102 in 1404de7

	local selectors = {}
	for _, v in ipairs(self._test_references) do
	if v.type == "test" then
	table.insert(selectors, "-m=" .. v.qualified_name .. "#" .. v.method_name)
	elseif v.type == "file" then
	table.insert(selectors, "-c=" .. v.qualified_name)
	elseif v.type == "dir" then
	selectors = "-p=" .. v.qualified_name
	end
	end

-	table.insert(selectors, "-m=" .. v.qualified_name .. "#" .. v.method_name)
+	table.insert(selectors, "-m " .. v.qualified_name .. "#" .. v.method_name)
-	table.insert(selectors, "-c=" .. v.qualified_name)
+	table.insert(selectors, "-c " .. v.qualified_name)
-	selectors = "-p=" .. v.qualified_name
+	selectors = "-p " .. v.qualified_name

(The downloaded version of JUnit that comes with neotest-java complained with the = for the short parameter name, requiring a whitespace)

neotest-java/lua/neotest-java/command/jdtls.lua

Lines 67 to 73 in 1404de7

	M.get_classpath_file_argument = function(report_dir, additional_classpath_entries)
	local classpath = table.concat(M.get_classpath(additional_classpath_entries), ":")
	local temp_file = compatible_path(report_dir .. "/.cp")
	write_file(temp_file, ("-cp %s"):format(classpath))
	return ("@%s"):format(temp_file)
	end

-	local classpath = table.concat(M.get_classpath(additional_classpath_entries), ":")
+	local classpath = table.concat(M.get_classpath(additional_classpath_entries), ";")
-	return ("@%s"):format(temp_file)
+	return ("`@%s"):format(temp_file)

(For Powershell, the semicolon is employed to separate multiple paths; and the backtick is needed before the @ to escape it)

Debugging tests is still hanging up my Neovim, though, even though I got it working when I run it in WSL. It must be something related to my Lazyvim configuration. I will investigate it further and report back.

So, I noticed that Neovim doesn't hang when I start the DAP as a debugging session and terminate it before running the tests. In WSL, I noticed the same pattern: if I tried to debug defore starting DAP as a debugging session first, it would hang up.

About the edit shown above, I could work on a pull request to detect the shell and set the parameters accordingly.