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import {TextEncoder} from 'util';
import {Readable} from 'stream';
import utils from "../utils.js";
import readBlob from "./readBlob.js";
const BOUNDARY_ALPHABET = utils.ALPHABET.ALPHA_DIGIT + '-_';
const textEncoder = new TextEncoder();
const CRLF = '\r\n';
const CRLF_BYTES = textEncoder.encode(CRLF);
const CRLF_BYTES_COUNT = 2;
class FormDataPart {
constructor(name, value) {
const {escapeName} = this.constructor;
const isStringValue = utils.isString(value);
let headers = `Content-Disposition: form-data; name="${escapeName(name)}"${
!isStringValue && value.name ? `; filename="${escapeName(value.name)}"` : ''
}${CRLF}`;
if (isStringValue) {
value = textEncoder.encode(String(value).replace(/\r?\n|\r\n?/g, CRLF));
} else {
headers += `Content-Type: ${value.type || "application/octet-stream"}${CRLF}`
}
this.headers = textEncoder.encode(headers + CRLF);
this.contentLength = isStringValue ? value.byteLength : value.size;
this.size = this.headers.byteLength + this.contentLength + CRLF_BYTES_COUNT;
this.name = name;
this.value = value;
}
async *encode(){
yield this.headers;
const {value} = this;
if(utils.isTypedArray(value)) {
yield value;
} else {
yield* readBlob(value);
}
yield CRLF_BYTES;
}
static escapeName(name) {
return String(name).replace(/[\r\n"]/g, (match) => ({
'\r' : '%0D',
'\n' : '%0A',
'"' : '%22',
}[match]));
}
}
const formDataToStream = (form, headersHandler, options) => {
const {
tag = 'form-data-boundary',
size = 25,
boundary = tag + '-' + utils.generateString(size, BOUNDARY_ALPHABET)
} = options || {};
if(!utils.isFormData(form)) {
throw TypeError('FormData instance required');
}
if (boundary.length < 1 || boundary.length > 70) {
throw Error('boundary must be 10-70 characters long')
}
const boundaryBytes = textEncoder.encode('--' + boundary + CRLF);
const footerBytes = textEncoder.encode('--' + boundary + '--' + CRLF + CRLF);
let contentLength = footerBytes.byteLength;
const parts = Array.from(form.entries()).map(([name, value]) => {
const part = new FormDataPart(name, value);
contentLength += part.size;
return part;
});
contentLength += boundaryBytes.byteLength * parts.length;
contentLength = utils.toFiniteNumber(contentLength);
const computedHeaders = {
'Content-Type': `multipart/form-data; boundary=${boundary}`
}
if (Number.isFinite(contentLength)) {
computedHeaders['Content-Length'] = contentLength;
}
headersHandler && headersHandler(computedHeaders);
return Readable.from((async function *() {
for(const part of parts) {
yield boundaryBytes;
yield* part.encode();
}
yield footerBytes;
})());
};
export default formDataToStream;