tutorial.lua

local runner = require("async.runner")
local wrap = require("async.wrap")
local wait = require("async.waits.wait_with_error_handler")

local function success_async(callback)
	local timer = vim.loop.new_timer()

	assert(timer)

	timer:start(2000, 0, function()
		-- First parameter is the error
		callback(nil, "hello world")
	end)
end

local function fail_async(callback)
	local timer = vim.loop.new_timer()

	assert(timer)

	timer:start(2000, 0, function()
		-- First parameter is the error
		callback("something went wrong", nil)
	end)
end

local function log(message)
	vim.print(os.date("%H:%M:%S") .. " " .. message)
end

vim.cmd.messages("clear")

local nested = runner(function()
	local success_sync = wrap(success_async)
	local fail_sync = wrap(fail_async)

	local success_result = wait(success_sync())
	-- here we get the result because there is no error
	log("success_result is: " .. success_result)

	-- following is going to fail and error will get caught by
	-- the parent runner function's 'catch'
	wait(fail_sync())
end)

runner(function()
		log("starting the execution")
		-- just wait for nested runner to complete the execution
		wait(nested.run)
	end)
	.catch(function(err)
		log("parent error handler " .. err)
	end)
	.run()