VS Code task process stdout/stderr - visual-studio-code

Question

I'm attempting to write some test for a VS Code extension.
The extension basically creates some tasks, using ShellExecution to run a local executable file, for example:
new Task(
definition,
folder,
name,
source,
new ShellExecution('./runme', { cwd })
);
I would like to be able to test the shell process, but don't have access to this process and so cannot attach to any of the output streams nor get the exit code.
In my tests, I execute the task like so: await vscode.tasks.executeTask(task); which runs successfully regardless of the exit code of the process created by ShellExecution.
Is there any way I can get access to the child process generated from executing a task?

Answer 1

With Node.js' child_process this is simple to do. I use it to run an external Java jar and capture its output to get the errors. The main part is:
let java = child_process.spawn("java", parameters, spawnOptions);
let buffer = "";
java.stderr.on("data", (data) => {
let text = data.toString();
if (text.startsWith("Picked up _JAVA_OPTIONS:")) {
let endOfInfo = text.indexOf("\n");
if (endOfInfo == -1) {
text = "";
} else {
text = text.substr(endOfInfo + 1, text.length);
}
}
if (text.length > 0) {
buffer += "\n" + text;
}
});
java.on("close", (code) => {
let parser = new ErrorParser(dependencies);
if (parser.convertErrorsToDiagnostics(buffer)) {
thisRef.setupInterpreters(options.outputDir);
resolve(fileList);
} else {
reject(buffer); // Treat this as non-grammar error (e.g. Java exception).
}
});