syntax-error

What is syntax-error?

The syntax-error npm package is used to check JavaScript code for syntax errors. It can be used as a module in Node.js to detect and report syntax errors in code strings.

What are syntax-error's main functionalities?

Check for syntax errors in a string of code

This feature allows you to pass a string of JavaScript code and optionally a filename, and it will return an error object if there are syntax errors in the code. If there are no syntax errors, it returns undefined.

const syntaxError = require('syntax-error');
const src = 'var foo = 1;
var bar = ;';
const err = syntaxError(src, 'foo.js');
if (err) console.error('Error:', err);

Other packages similar to syntax-error

jshint

JSHint is a static code analysis tool used in software development for checking if JavaScript source code complies with coding rules. It is more comprehensive than syntax-error as it checks for errors and potential problems in code style and logic, not just syntax errors.

eslint

ESLint is a pluggable and configurable linter tool for identifying and reporting on patterns in JavaScript. It is more advanced than syntax-error, offering customizable rules for coding standards and errors, including syntax errors, code smells, and stylistic issues.

acorn

Acorn is a tiny, fast JavaScript parser, written completely in JavaScript. While syntax-error uses Acorn internally to detect syntax errors, Acorn itself is a more powerful tool that can be used for parsing JavaScript code into an abstract syntax tree (AST), which can then be analyzed or manipulated for various purposes.

README

syntax-error

Detect and report syntax errors in source code strings.

When you type node src.js you get a friendly error report about exactly where the syntax error is. This module lets you check for syntax errors and report them in a similarly friendly format that wrapping a try/catch around Function() or vm.runInNewContext() doesn't get you.

example

var fs = require('fs');
var check = require('syntax-error');

var file = __dirname + '/src.js';
var src = fs.readFileSync(file);

var err = check(src, file);
if (err) {
    console.error('ERROR DETECTED' + Array(62).join('!'));
    console.error(err);
    console.error(Array(76).join('-'));
}

---

$ node check.js
ERROR DETECTED!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

/home/substack/projects/node-syntax-error/example/src.js:5
        if (Array.isArray(x) res.push.apply(res, x);
                             ^
ParseError: Unexpected identifier
---------------------------------------------------------------------------

methods

var check = require('syntax-error')

var err = check(src, file, opts={})

Check the source code string src for syntax errors. Optionally you can specify a filename file that will show up in the output.

If src has a syntax error, return an error object err that can be printed or stringified.

If there are no syntax errors in src, return undefined.

Options will be passed through to acorn-node. acorn-node defaults to options that match the most recent Node versions.

err.toString()

Return the long string description with a source snippet and a ^ under pointing exactly where the error was detected.

attributes

err.message

short string description of the error type

err.line

line number of the error in the original source (indexing starts at 1)

err.column

column number of the error in the original source (indexing starts at 1)

install

With npm do:

npm install syntax-error

license

MIT