Consider using xpcall in try block

[pilaoda]

Error message from pcall only include the first line that error happened but not the full stack traceback, but this can be done by compiling to using xpcall and pass debug.traceback as second arg:

local result
local function ____catch(err)
    print("catch:", err)
end
local ____try, ____hasReturned = xpcall(
    function()
        result = dosomething(args)
    end,
    debug.traceback
)
if not ____try then
    ____catch(____hasReturned)
end

Although custom plugin can implement this feature, but plugin can not rewrite lualib such as pcall in Promise.lua

[lolleko]

Unfortunately, it is not as simple as replacing pcall with xpcall & debug.traceback. Because using xpcall & debug.traceback will break our throw implementation.

e.g.

      try {
          throw "Hello, I am an Error!";
      } catch (error) {
          return error;
      }

would return:

Hello, I am an Error!
    stack traceback:
        [C]: in function 'error'
        [string \"...\"]:17: in function <[string \"...\"]:16>
        [C]: in function 'xpcall'
        [string \"...\"]:15: in function <[string \"...\"]:6>
        (...tail calls...)
        [string \"...\"]:3: in main chunk

instead of the correct/JS behavior

Hello, I am an Error!

This can possibly be solved by changing the way we throw string literals. Another solution might be to create a custom/adapted implementation of debug.tracepack.

[BribeFromTheHive]

Likely the best middle ground is that an empty catch block can compile to an xpcall, and a non-empty one can compile as-is. Same with un-caught rejected promise objects, if they don't already work that way.

[pilaoda]

https://github.com/TypeScriptToLua/TypeScriptToLua/blob/16a8eb3a5aed582f31d5f2306d70d3801983deca/src/lualib/Await.ts#L55-L58 coroutine.resume also lack of stack trace, the asyncCoroutine should pass into debug.traceback as the first argument to get the error trace in coroutine context.

[fadabaerobe6]

-- Reimplemented pcall function
_G.pcall = function(func, ...)
    local results = table.pack(
        xpcall(func, function(err)
            -- Do nothing here, just return the error object
            return err..'\n'..debug.traceback()
        end, ...)
    )
    local status = table.remove(results, 1)
    if not status then
        -- When an error occurs, err is the error message, mimicking the behavior of pcall
        return false, table.unpack(results)
    else
        -- No error occurred, return all the additional parameters returned by xpcall
        return true, table.unpack(results)
    end
end

We can use xpcall to override pcall method to find the origin trackback