In my Discord.JS bot, I need to be able to handle all uncaught exceptions.
I understand that I can use process.on('uncaughtException',. . .', but I need the ability to send a message to the channel where the error was triggered (if the error was triggered by a command, of course), and send instructions to report the error (I already have the error reporting method figured out, and I know how to do it without giving them a stack trace or other info — that is not my question).
Of course, I could always just put a try statement in every single part of the code where this is the slightest chance of an error, but this would get very messy. Of course, I could have a module that does the error handling, but what happens if I need to add another argument to the error handler that will require a change in the try statements? I will have to spend hours going through every single file in the bot.
I understand that I will probably need to have some try statements and other error handling methods, but I need to find a more efficient way to do this if possible.
Edit: Yes, I have already tried using a try-catch statement in the command handler. It did nothing. Code:
const {bot} = require('../index');
const { logError } = require("./utils/ErrorHandling.js");
bot.on("interactionCreate", async interaction => {
if (!interaction.isCommand()) return;
let cmd = interaction.commandName;
if (bot.commands.has(cmd)) {
command = bot.commands.get(cmd);
} else {
command = bot.commands.get(bot.aliases.get(cmd));
}
try {
if (command) command.run(bot, interaction);
} catch (e) {
logError(e, interaction.channel);
}
});
Error handler module:
const { errorLoggingWebhook, supportServer } = require("../config.json")
const fetch = require("node-fetch");
module.exports = {
"logError": (error, discordChannel) => {
var errorID = createUUID();
var params = {
username: "Aspectfully Error Logging",
content: `**${errorID}**:
```
${error}
````,
}
fetch(errorLoggingWebhook, {
method: "POST",
headers: {
'Content-type': 'application/json'
},
body: JSON.stringify(params)
}).then(res => {
console.log(res);
})
return discordChannel.send(`An error occured while running that command.
If this continues to occur, please join our [support server](${supportServer}) and tell them an error is occuring.
Also, give them the error ID `${errorID}`.`)
}
}
This is an error that occurs. I know there is an easy solution to prevent it from occurring, but I just haven’t implemented it yet. This way, I can test the error handling function.
(The error is because I am intentionally trying to process a page from Wikipedia that doesn’t exist using the Wikipedia API as if it does exist, therefore trying to read values that don’t exist)
C:UsersbekfeOneDriveDocumentsAspectfullycodecommandswikipedia.js:36
wikiParseContents = wikiParse(Object.values(Object.values(JSON.parse(body))[0].text)[0], `https://en.wikipedia.org/wiki/${encodeURI(suffix)}`);
^
TypeError: Cannot convert undefined or null to object
at Function.values (<anonymous>)
at C:UsersbekfeOneDriveDocumentsAspectfullycodecommandswikipedia.js:36:42
at processTicksAndRejections (node:internal/process/task_queues:96:5)
I am not asking how to solve this specific error. I already know how to solve it. The problem is that the error handler doesn’t catch it as an error — my question is about solving this specific error.
I have also tried doing the await function this way, but I have got the same result:
const {bot} = require('../index');
const { logError } = require("../utils/ErrorHandling.js");
bot.on("interactionCreate", async interaction => {
if (!interaction.isCommand()) return;
let cmd = interaction.commandName;
if (bot.commands.has(cmd)) {
command = bot.commands.get(cmd);
} else {
command = bot.commands.get(bot.aliases.get(cmd));
}
if (command) {
try {
await command.run(bot, interaction);
} catch (e) {
logError(e, interaction.channel);
}
}
});
Bot Designer for Discord — Wiki
Error Handling
In BDScript 2 you can handle errors returned by functions or limiters (such as $cooldown[] or $onlyIf[]).
Error Handling Functions
$try
Used to open the Error Handling block.
$endtry
Used to close the Error Handling block.
$catch
Used to create a sub-block between $try and $endtry that will contain the code that will be executed when an error occurs.
$error[]
Used in the $catch block to return error information.
Possible Arguments
command— returns the name of the function that returned the error.message— returns the error message that was received.source— returns the content of the line where the error occurred.row— returns the number of the row in the code where the error occurred.column— returns the number of the column in the code where the error occurred.
Examples
Function Error
$nomention
$try
$color[FFFFFF]
$title[Hi]
$description[Some broken code;]
$catch
$color[E74C3C]
$title[Error Handling]
$addField[Function:;$error[command]]
$addField[Error:;$error[message]]
$endtry
Limiter Error
As a way to use Error Handling with Limiter Errors, we’ll use $cooldown[]. With the help of Error Handling, we can make a nice cooldown error message.
To handle only the error of our limiter, we will use a temporary variable and if statements.
If $cooldown[] returns an error, the value of the temporary variable will be set to true (in which case our nice error message will be sent).
Note: The
error messageargument in$cooldown[]must be left blank.
$nomention
$var[cooldownError;false]
$try
$cooldown[3m;]
$catch
$var[cooldownError;true]
$endtry
$if[$var[cooldownError]==false]
Hey $username, are you making an example for the guide?
$else
$color[E74C3C]
$author[Oops, $username!]
$authorIcon[$authorAvatar]
$title[You have a cooldown!]
$description[Come back <t:$sum[$getTimestamp;$getCooldown[normal]]:R>.]
$endif
