lts/lib/internal/process/warning.js
'use strict';
const {
ArrayIsArray,
Error,
} = primordials;
const { ERR_INVALID_ARG_TYPE } = require('internal/errors').codes;
// Lazily loaded
let fs;
let fd;
let warningFile;
function lazyOption() {
// This will load `warningFile` only once. If the flag is not set,
// `warningFile` will be set to an empty string.
if (warningFile === undefined) {
warningFile = require('internal/options')
.getOptionValue('--redirect-warnings');
}
return warningFile;
}
// If we can't write to stderr, we'd like to make this a noop,
// so use console.error.
let error;
function writeOut(message) {
if (!error) {
error = require('internal/console/global').error;
}
error(message);
}
function writeToFile(message) {
if (fd === undefined) {
fs = require('fs');
try {
fd = fs.openSync(warningFile, 'a');
} catch {
return writeOut(message);
}
process.on('exit', () => {
try {
fs.closeSync(fd);
} catch {}
});
}
fs.appendFile(fd, `${message}\n`, (err) => {
if (err) {
writeOut(message);
}
});
}
function doEmitWarning(warning) {
return () => process.emit('warning', warning);
}
function onWarning(warning) {
if (!(warning instanceof Error)) return;
const isDeprecation = warning.name === 'DeprecationWarning';
if (isDeprecation && process.noDeprecation) return;
const trace = process.traceProcessWarnings ||
(isDeprecation && process.traceDeprecation);
let msg = `(${process.release.name}:${process.pid}) `;
if (warning.code)
msg += `[${warning.code}] `;
if (trace && warning.stack) {
msg += `${warning.stack}`;
} else {
const toString =
typeof warning.toString === 'function' ?
warning.toString : Error.prototype.toString;
msg += `${toString.apply(warning)}`;
}
if (typeof warning.detail === 'string') {
msg += `\n${warning.detail}`;
}
const warningFile = lazyOption();
if (warningFile) {
return writeToFile(msg);
}
writeOut(msg);
}
// process.emitWarning(error)
// process.emitWarning(str[, type[, code]][, ctor])
// process.emitWarning(str[, options])
function emitWarning(warning, type, code, ctor, now) {
let detail;
if (type !== null && typeof type === 'object' && !ArrayIsArray(type)) {
ctor = type.ctor;
code = type.code;
if (typeof type.detail === 'string')
detail = type.detail;
type = type.type || 'Warning';
} else if (typeof type === 'function') {
ctor = type;
code = undefined;
type = 'Warning';
}
if (type !== undefined && typeof type !== 'string') {
throw new ERR_INVALID_ARG_TYPE('type', 'string', type);
}
if (typeof code === 'function') {
ctor = code;
code = undefined;
} else if (code !== undefined && typeof code !== 'string') {
throw new ERR_INVALID_ARG_TYPE('code', 'string', code);
}
if (typeof warning === 'string') {
// Improve error creation performance by skipping the error frames.
// They are added in the `captureStackTrace()` function below.
const tmpStackLimit = Error.stackTraceLimit;
Error.stackTraceLimit = 0;
// eslint-disable-next-line no-restricted-syntax
warning = new Error(warning);
Error.stackTraceLimit = tmpStackLimit;
warning.name = String(type || 'Warning');
if (code !== undefined) warning.code = code;
if (detail !== undefined) warning.detail = detail;
// eslint-disable-next-line no-restricted-syntax
Error.captureStackTrace(warning, ctor || process.emitWarning);
} else if (!(warning instanceof Error)) {
throw new ERR_INVALID_ARG_TYPE('warning', ['Error', 'string'], warning);
}
if (warning.name === 'DeprecationWarning') {
if (process.noDeprecation)
return;
if (process.throwDeprecation)
throw warning;
}
if (now) process.emit('warning', warning);
else process.nextTick(doEmitWarning(warning));
}
module.exports = {
onWarning,
emitWarning
};