1
Files
2025/tools/lib/http.js

134 lines
3.5 KiB
JavaScript

const { fetch } = require("undici");
const UserAgent = require("user-agents");
const DEFAULT_ACCEPT =
"text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,*/*;q=0.8";
const DEFAULT_ACCEPT_LANGUAGE = "fr-FR,fr;q=0.9,en;q=0.7";
const DEFAULT_TIMEOUT_MS = 5000;
const DEFAULT_MAX_REDIRECTS = 5;
function buildUserAgent(preferred) {
if (typeof preferred === "string" && preferred.trim()) {
return preferred.trim();
}
const ua = new UserAgent();
return ua.toString();
}
async function fetchWithRedirects(targetUrl, options, maxRedirects) {
let currentUrl = targetUrl;
let response = null;
let redirects = 0;
while (redirects <= maxRedirects) {
response = await fetch(currentUrl, { ...options, redirect: "manual" });
const location = response.headers.get("location");
if (
response.status >= 300 &&
response.status < 400 &&
location &&
redirects < maxRedirects
) {
if (response.body && typeof response.body.cancel === "function") {
try {
await response.body.cancel();
} catch (_) {
// Ignore cancellation errors; we're moving to the next hop.
}
}
currentUrl = new URL(location, currentUrl).toString();
redirects += 1;
continue;
}
break;
}
return response;
}
async function probeUrl(url, options = {}) {
const method = typeof options.method === "string" ? options.method.toUpperCase() : "HEAD";
const timeoutMs = Number.isFinite(options.timeoutMs) ? options.timeoutMs : DEFAULT_TIMEOUT_MS;
const maxRedirects = Number.isFinite(options.maxRedirects)
? options.maxRedirects
: DEFAULT_MAX_REDIRECTS;
const userAgent = buildUserAgent(options.userAgent);
const headers = {
"user-agent": userAgent,
"accept-language": DEFAULT_ACCEPT_LANGUAGE,
"accept": DEFAULT_ACCEPT,
...(options.headers || {}),
};
const controller = new AbortController();
const timer = setTimeout(() => controller.abort(), timeoutMs);
try {
const response = await fetchWithRedirects(
url,
{
method,
headers,
signal: controller.signal,
},
maxRedirects
);
const status = response ? response.status : null;
const finalUrl = response?.url || url;
if (response?.body && typeof response.body.cancel === "function") {
try {
await response.body.cancel();
} catch (_) {
// Ignore cancellation errors; the status is all we needed.
}
}
return {
status,
finalUrl,
method,
errorType: null,
};
} catch (error) {
if (error.name === "AbortError") {
return {
status: null,
finalUrl: url,
method,
errorType: "timeout",
};
}
return {
status: null,
finalUrl: url,
method,
errorType: "network",
message: error.message,
};
} finally {
clearTimeout(timer);
}
}
function shouldRetry(result) {
if (!result) return true;
if (result.errorType) return true;
if (typeof result.status !== "number") return true;
return result.status >= 400;
}
async function checkUrl(url, options = {}) {
const firstMethod = options.firstMethod || "HEAD";
let result = await probeUrl(url, { ...options, method: firstMethod });
if (options.retryWithGet !== false && shouldRetry(result)) {
result = await probeUrl(url, { ...options, method: "GET" });
}
return result;
}
module.exports = {
buildUserAgent,
checkUrl,
probeUrl,
shouldRetry,
};