prefer-blob-reading-methods.md

prefer-blob-reading-methods

📝 Prefer Blob#arrayBuffer() over FileReader#readAsArrayBuffer(…) and Blob#text() over FileReader#readAsText(…).

💼 This rule is enabled in the following configs: ✅ recommended, ☑️ unopinionated.

FileReader predates promises, and the newer Blob#arrayBuffer() and Blob#text() methods are much cleaner and easier to use.

Examples

// ❌
const arrayBuffer = await new Promise((resolve, reject) => {
	const fileReader = new FileReader();
	fileReader.addEventListener('load', () => {
		resolve(fileReader.result);
	});
	fileReader.addEventListener('error', () => {
		reject(fileReader.error);
	});
	fileReader.readAsArrayBuffer(blob);
});

// ✅
const arrayBuffer = await blob.arrayBuffer();

// ❌
fileReader.readAsText(blob);

// ✅
const text = await blob.text();

// ✅
fileReader.readAsText(blob, 'ascii');

// ✅
fileReader.readAsDataURL(blob);