120 lines
2.8 KiB
JavaScript
120 lines
2.8 KiB
JavaScript
// Based on https://github.com/tmpvar/jsdom/blob/aa85b2abf07766ff7bf5c1f6daafb3726f2f2db5/lib/jsdom/living/blob.js
|
|
// (MIT licensed)
|
|
|
|
import Stream from 'stream';
|
|
|
|
// fix for "Readable" isn't a named export issue
|
|
const Readable = Stream.Readable;
|
|
|
|
export const BUFFER = Symbol('buffer');
|
|
const TYPE = Symbol('type');
|
|
|
|
export default class Blob {
|
|
constructor() {
|
|
this[TYPE] = '';
|
|
|
|
const blobParts = arguments[0];
|
|
const options = arguments[1];
|
|
|
|
const buffers = [];
|
|
let size = 0;
|
|
|
|
if (blobParts) {
|
|
const a = blobParts;
|
|
const length = Number(a.length);
|
|
for (let i = 0; i < length; i++) {
|
|
const element = a[i];
|
|
let buffer;
|
|
if (element instanceof Buffer) {
|
|
buffer = element;
|
|
} else if (ArrayBuffer.isView(element)) {
|
|
buffer = Buffer.from(element.buffer, element.byteOffset, element.byteLength);
|
|
} else if (element instanceof ArrayBuffer) {
|
|
buffer = Buffer.from(element);
|
|
} else if (element instanceof Blob) {
|
|
buffer = element[BUFFER];
|
|
} else {
|
|
buffer = Buffer.from(typeof element === 'string' ? element : String(element));
|
|
}
|
|
size += buffer.length;
|
|
buffers.push(buffer);
|
|
}
|
|
}
|
|
|
|
this[BUFFER] = Buffer.concat(buffers);
|
|
|
|
let type = options && options.type !== undefined && String(options.type).toLowerCase();
|
|
if (type && !/[^\u0020-\u007E]/.test(type)) {
|
|
this[TYPE] = type;
|
|
}
|
|
}
|
|
get size() {
|
|
return this[BUFFER].length;
|
|
}
|
|
get type() {
|
|
return this[TYPE];
|
|
}
|
|
text() {
|
|
return Promise.resolve(this[BUFFER].toString())
|
|
}
|
|
arrayBuffer() {
|
|
const buf = this[BUFFER];
|
|
const ab = buf.buffer.slice(buf.byteOffset, buf.byteOffset + buf.byteLength);
|
|
return Promise.resolve(ab);
|
|
}
|
|
stream() {
|
|
const readable = new Readable();
|
|
readable._read = () => {};
|
|
readable.push(this[BUFFER]);
|
|
readable.push(null);
|
|
return readable;
|
|
}
|
|
toString() {
|
|
return '[object Blob]'
|
|
}
|
|
slice() {
|
|
const size = this.size;
|
|
|
|
const start = arguments[0];
|
|
const end = arguments[1];
|
|
let relativeStart, relativeEnd;
|
|
if (start === undefined) {
|
|
relativeStart = 0;
|
|
} else if (start < 0) {
|
|
relativeStart = Math.max(size + start, 0);
|
|
} else {
|
|
relativeStart = Math.min(start, size);
|
|
}
|
|
if (end === undefined) {
|
|
relativeEnd = size;
|
|
} else if (end < 0) {
|
|
relativeEnd = Math.max(size + end, 0);
|
|
} else {
|
|
relativeEnd = Math.min(end, size);
|
|
}
|
|
const span = Math.max(relativeEnd - relativeStart, 0);
|
|
|
|
const buffer = this[BUFFER];
|
|
const slicedBuffer = buffer.slice(
|
|
relativeStart,
|
|
relativeStart + span
|
|
);
|
|
const blob = new Blob([], { type: arguments[2] });
|
|
blob[BUFFER] = slicedBuffer;
|
|
return blob;
|
|
}
|
|
}
|
|
|
|
Object.defineProperties(Blob.prototype, {
|
|
size: { enumerable: true },
|
|
type: { enumerable: true },
|
|
slice: { enumerable: true }
|
|
});
|
|
|
|
Object.defineProperty(Blob.prototype, Symbol.toStringTag, {
|
|
value: 'Blob',
|
|
writable: false,
|
|
enumerable: false,
|
|
configurable: true
|
|
});
|