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#!/usr/bin/env node
/**
* @fileoverview Main CLI that is run via the eslint command.
* @author Nicholas C. Zakas
*/
/* eslint no-console:off -- CLI */
"use strict";
// to use V8's code cache to speed up instantiation time
require("v8-compile-cache");
// must do this initialization *before* other requires in order to work
if (process.argv.includes("--debug")) {
require("debug").enable("eslint:*,-eslint:code-path,eslintrc:*");
}
//------------------------------------------------------------------------------
// Helpers
//------------------------------------------------------------------------------
/**
* Read data from stdin til the end.
*
* Note: See
* - https://github.com/nodejs/node/blob/master/doc/api/process.md#processstdin
* - https://github.com/nodejs/node/blob/master/doc/api/process.md#a-note-on-process-io
* - https://lists.gnu.org/archive/html/bug-gnu-emacs/2016-01/msg00419.html
* - https://github.com/nodejs/node/issues/7439 (historical)
*
* On Windows using `fs.readFileSync(STDIN_FILE_DESCRIPTOR, "utf8")` seems
* to read 4096 bytes before blocking and never drains to read further data.
*
* The investigation on the Emacs thread indicates:
*
* > Emacs on MS-Windows uses pipes to communicate with subprocesses; a
* > pipe on Windows has a 4K buffer. So as soon as Emacs writes more than
* > 4096 bytes to the pipe, the pipe becomes full, and Emacs then waits for
* > the subprocess to read its end of the pipe, at which time Emacs will
* > write the rest of the stuff.
* @returns {Promise<string>} The read text.
*/
function readStdin() {
return new Promise((resolve, reject) => {
let content = "";
let chunk = "";
process.stdin
.setEncoding("utf8")
.on("readable", () => {
while ((chunk = process.stdin.read()) !== null) {
content += chunk;
}
})
.on("end", () => resolve(content))
.on("error", reject);
});
}
/**
* Get the error message of a given value.
* @param {any} error The value to get.
* @returns {string} The error message.
*/
function getErrorMessage(error) {
// Lazy loading because this is used only if an error happened.
const util = require("util");
// Foolproof -- third-party module might throw non-object.
if (typeof error !== "object" || error === null) {
return String(error);
}
// Use templates if `error.messageTemplate` is present.
if (typeof error.messageTemplate === "string") {
try {
const template = require(`../messages/${error.messageTemplate}.js`);
return template(error.messageData || {});
} catch {
// Ignore template error then fallback to use `error.stack`.
}
}
// Use the stacktrace if it's an error object.
if (typeof error.stack === "string") {
return error.stack;
}
// Otherwise, dump the object.
return util.format("%o", error);
}
/**
* Catch and report unexpected error.
* @param {any} error The thrown error object.
* @returns {void}
*/
function onFatalError(error) {
process.exitCode = 2;
const { version } = require("../package.json");
const message = getErrorMessage(error);
console.error(`
Oops! Something went wrong! :(
ESLint: ${version}
${message}`);
}
//------------------------------------------------------------------------------
// Execution
//------------------------------------------------------------------------------
(async function main() {
process.on("uncaughtException", onFatalError);
process.on("unhandledRejection", onFatalError);
// Call the config initializer if `--init` is present.
if (process.argv.includes("--init")) {
// `eslint --init` has been moved to `@eslint/create-config`
console.warn("You can also run this command directly using 'npm init @eslint/config'.");
const spawn = require("cross-spawn");
spawn.sync("npm", ["init", "@eslint/config"], { encoding: "utf8", stdio: "inherit" });
return;
}
// Otherwise, call the CLI.
process.exitCode = await require("../lib/cli").execute(
process.argv,
process.argv.includes("--stdin") ? await readStdin() : null
);
}()).catch(onFatalError);