[Windows] Missed support of long path

[AlttiRi]

Possible bug

It works fine until I pass a long path to load an image with sharp function.

As workaround I can manually read the file with Node.js and pass ArrayBuffer of the image to sharp function instead of the image path string.

Is this a possible bug in a feature of sharp, unrelated to installation?

It's bug of handling a Windows filesystem long path.

ENV

• Window 10
• Node v20.18.0
• Sharp 0.33.5

What are the steps to reproduce?

Run the TS code.

What is the expected behaviour?

No errors. A workaround is not needed. It just works from the box.

Please provide a minimal, standalone code sample, without other dependencies, that demonstrates this problem

import sharp from "sharp";
import fs from "node:fs/promises";
import path from "node:path";

const imageName = "image-for-long-path-3x3.png";

// create an image
await saveImageDataWithSharp({
    data: new Uint8ClampedArray([255, 255, 255, 0, 0, 0, 128, 128, 128]),
    width: 3,
    height: 3,
    channels: 1
}, imageName);

// move it to a long path directory
const dirPath = path.join("./", ...[
    "a".repeat(100), "b".repeat(100), "c".repeat(100), "d".repeat(100)
]);
await fs.mkdir(dirPath, {recursive: true});

const newPath = path.join(dirPath, imageName);
await fs.rename(imageName, newPath);

// ---

// it works fine
console.log("reading with fs:");
console.log(await getImageDataWithSharp((await fs.readFile(newPath)).buffer));

console.log();

// it throws an error
console.log("reading with sharp:");
try {
    console.log(await getImageDataWithSharp(newPath));
} catch (e) {
    console.log((e as Error).message);
}


// ---

export function saveImageDataWithSharp(imageData: ImageDataLikeEx, outputFilePath: string): Promise<sharp.OutputInfo> {
    const image: sharp.Sharp = sharp(imageData.data, {
        raw: {
            width: imageData.width,
            height: imageData.height,
            channels: imageData.channels ? imageData.channels : 4,
        }
    });
    return image.toFile(outputFilePath);
}

export async function getImageDataWithSharp(inputData: string | ArrayBuffer): Promise<ImageDataLike> {
    const imageData = await sharp(inputData)
        .ensureAlpha()
        .raw()
        .toBuffer({resolveWithObject: true});
    const {data, info} = imageData;
    return {
        width: info.width,
        height: info.height,
        data: new Uint8ClampedArray(data.buffer),
    };
}

type ImageDataLike = {
    data:   Uint8ClampedArray
    width:  number
    height: number
};
type ImageDataLikeEx = {
    data:   Uint8ClampedArray | Uint8Array
    width:  number
    height: number
    channels?: 4 | 1 | 2 | 3
};

reading with fs:
{
  width: 3,
  height: 3,
  data: Uint8ClampedArray(36) [
    255, 255, 255, 255, 255, 255, 255, 255,
    255, 255, 255, 255,   0,   0,   0, 255,
      0,   0,   0, 255,   0,   0,   0, 255,
    128, 128, 128, 255, 128, 128, 128, 255,
    128, 128, 128, 255
  ]
}

reading with sharp:
Input file is missing: aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa\bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb\cccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc\dddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddd\image-for-long-path-3x3.png

Please provide sample image(s) that help explain this problem

Generated.

[AlttiRi]

BTW, using path.toNamespacedPath(newPath)) also helps.
It simply resolves the path to absolute one and prepends \\?\.

[lovell]

Is it still the case that Windows has problems with filesystem paths longer than 260 characters? If so, use of toNamespacedPath is probably the right approach here.