Cannot read properties of null (reading 'byteLength')

I keep getting this error in my script but I can't figure out the cause of it.

TypeError: Cannot read properties of null (reading 'byteLength')
    at Object.pull (C:\Users\*\Documents\Bot\node_modules\undici\lib\web\fetch\body.js:66:20)
    at invokePromiseCallback (node:internal/webstreams/util:172:10)
    at Object.<anonymous> (node:internal/webstreams/util:177:23)
    at readableByteStreamControllerCallPullIfNeeded (node:internal/webstreams/readablestream:3145:24)
    at readableByteStreamControllerPullSteps (node:internal/webstreams/readablestream:3254:3)
    at [kPull] (node:internal/webstreams/readablestream:1201:5)
    at readableStreamDefaultReaderRead (node:internal/webstreams/readablestream:2269:39)
    at nextSteps (node:internal/webstreams/readablestream:493:7)
    at async writeIterable (C:\Users\*\Documents\Bot\node_modules\undici\lib\dispatcher\client-h1.js:1439:22)

TypeError: Cannot read properties of null (reading 'byteLength')
    at Object.pull (C:\Users\*\Documents\Bot\node_modules\undici\lib\web\fetch\body.js:66:20)
    at invokePromiseCallback (node:internal/webstreams/util:172:10)
    at Object.<anonymous> (node:internal/webstreams/util:177:23)
    at readableByteStreamControllerCallPullIfNeeded (node:internal/webstreams/readablestream:3145:24)
    at readableByteStreamControllerPullSteps (node:internal/webstreams/readablestream:3254:3)
    at [kPull] (node:internal/webstreams/readablestream:1201:5)
    at readableStreamDefaultReaderRead (node:internal/webstreams/readablestream:2269:39)
    at nextSteps (node:internal/webstreams/readablestream:493:7)
    at async writeIterable (C:\Users\*\Documents\Bot\node_modules\undici\lib\dispatcher\client-h1.js:1439:22)

Short code snippet:

if (interaction.commandName === "cardtest") {
    const canvas = createCanvas(700, 250);
    const context = canvas.getContext('2d');

    const backgroundPath = path.join(__dirname, "assets", "contribution-card-background.png")
    const background = await readFile(backgroundPath);
    const backgroundImage = new Image();
    backgroundImage.src = background;
    context.drawImage(backgroundImage, 0, 0, canvas.width, canvas.height);

    const attachment = new AttachmentBuilder(canvas.toBuffer('image/png'), { name: 'profile-image.png' });
    console.log(attachment)

    interaction.reply({ files: [attachment] });
}

if (interaction.commandName === "cardtest") {
    const canvas = createCanvas(700, 250);
    const context = canvas.getContext('2d');

    const backgroundPath = path.join(__dirname, "assets", "contribution-card-background.png")
    const background = await readFile(backgroundPath);
    const backgroundImage = new Image();
    backgroundImage.src = background;
    context.drawImage(backgroundImage, 0, 0, canvas.width, canvas.height);

    const attachment = new AttachmentBuilder(canvas.toBuffer('image/png'), { name: 'profile-image.png' });
    console.log(attachment)

    interaction.reply({ files: [attachment] });
}

16 Replies

d.js toolkit•5d ago

thom463sOP•5d ago

The code snippet is primarily from this sample: https://github.com/discordjs/guide/blob/main/code-samples/popular-topics/canvas/14/index.js

NyR•5d ago

What is your discord.js version? Can you do npm ls discord.js?

thom463sOP•5d ago

14.22.1

NyR•5d ago

Can you do, npm ls @discordjs/rest and show me the output?

thom463sOP•5d ago

NyR•5d ago

Weird, this was fixed. I'm not sure if the fix was backported tho

thom463sOP•5d ago

i've been stuck at this problem for a few hours now, I might just scrap the entire thing for the time being

NyR•5d ago

The original issue was from undici which labeled it as non-issue. There was a fix from d.js side for dev in this pr https://github.com/discordjs/discord.js/pull/11015

thom463sOP•5d ago

that sucks not really sure where to go from there

NyR•5d ago

Do you have undici installed separately?

thom463sOP•5d ago

yeah

NyR•5d ago

Then that's likely the issue, the version affected with the bug is not used by d.js, so you installing the latest version could be the issue here

thom463sOP•5d ago

let me try and uninstall

thom463sOP•5d ago

the built attachment exists I think, but the image is never sent via reply

thom463sOP•5d ago

the error doesnt show up anymore either theres nothing wrong with this is there

const attachment = new AttachmentBuilder(canvas.toBuffer('image/png'), { name: 'profile-image.png' });
return interaction.reply({ files: [attachment] })

const attachment = new AttachmentBuilder(canvas.toBuffer('image/png'), { name: 'profile-image.png' });
return interaction.reply({ files: [attachment] })

so things work now because I also had noblox.js installed which was interferring with the discord.js' undici but now my problem is how I can keep both packages without both versions of undici interfering with eachother

Gaming

Programming

Cannot read properties of null (reading 'byteLength')

Did you find this page helpful?