JSLint, The JavaScript Code Quality and Coverage Tool

Douglas Crockford douglas@crockford.com

Status

| Branch | [master

(v2026.4.30)](https://github.com/jslint-org/jslint/tree/master) | [beta

(Web Demo)](https://github.com/jslint-org/jslint/tree/beta) | [alpha

(Development)](https://github.com/jslint-org/jslint/tree/alpha) | |--:|:--:|:--:|:--:| | CI | | | | | Coverage | | | | | Demo | | | | | Artifacts | | | |

Table of Contents

1. Web Demo

2. Web Demo Archived

3. Quickstart Install

   • To install, just download and save https://www.jslint.com/jslint.mjs to file:
   • To run jslint.mjs in shell:
   • To import jslint.mjs in ES Module environment:
   • To import jslint.mjs in CommonJS environment:
   • To JSLint entire directory in shell:

4. Quickstart JSLint Report

   • To create a JSLint report in shell:
   • To create a JSLint report in javascript:

5. Quickstart V8 Coverage Report

   • To create V8 coverage report from Node.js / Npm program in shell:
   • To create V8 coverage report from Node.js / Npm program in javascript:

6. Quickstart JSLint in CodeMirror

7. Quickstart JSLint in Vim

8. Quickstart JSLint in VSCode

9. Documentation

   • API Doc
   • Directive /*jslint*/
     • /*jslint beta*/
     • /*jslint bitwise*/
     • /*jslint browser*/
     • /*jslint convert*/
     • /*jslint couch*/
     • /*jslint devel*/
     • /*jslint eval*/
     • /*jslint fart*/
     • /*jslint for*/
     • /*jslint getset*/
     • /*jslint indent2*/
     • /*jslint long*/
     • /*jslint node*/
     • /*jslint nomen*/
     • /*jslint single*/
     • /*jslint subscript*/
     • /*jslint this*/
     • /*jslint trace*/
     • /*jslint unordered*/
     • /*jslint white*/
   • Directive /*global*/
   • Directive /*property*/
   • Directive /*jslint-disable*/.../*jslint-enable*/
   • Directive //jslint-ignore-line
   • Directive /*coverage-disable*/.../*coverage-enable*/
   • Directive //coverage-ignore-line

10. Package Listing

11. Changelog

12. License

13. Devops Instruction

    • pull-request merge
    • branch-master commit
    • branch-master publish
    • vscode-jslint publish

Web Demo

• https://www.jslint.com

Web Demo Archived

• Web Demo 2020
• Web Demo 2014 (ES5 only)
• Web Demo 2013 (ES5, CSS, HTML)

Quickstart Install

To install, just download and save https://www.jslint.com/jslint.mjs to file:

#!/bin/sh

curl -L https://www.jslint.com/jslint.mjs > jslint.mjs

• shell output

To run jslint.mjs in shell:

#!/bin/sh

printf "console.log('hello world');\n" > hello.js

node jslint.mjs hello.js

• shell output

To import jslint.mjs in ES Module environment:

#!/bin/sh

node --input-type=module --eval '

/*jslint devel*/

// Import JSLint in ES Module environment.

import jslint from "./jslint.mjs";

let globals = ["caches", "indexedDb"];
let options = {browser: true};
let result;
let source = "console.log(\u0027hello world\u0027);\n";

// JSLint 

 and print <formatted_message>.

result = jslint.jslint(source, options, globals);
result.warnings.forEach(function ({
    formatted_message
}) {
    console.error(formatted_message);
});

'

• shell output

To import jslint.mjs in CommonJS environment:

#!/bin/sh

node --eval '

/*jslint devel*/
(async function () {
    let globals = ["caches", "indexedDb"];
    let jslint;
    let options = {browser: true};
    let result;
    let source = "console.log(\u0027hello world\u0027);\n";

// Import JSLint in CommonJS environment.

    jslint = await import("./jslint.mjs");
    jslint = jslint.default;

// JSLint 

 and print <formatted_message>.

    result = jslint.jslint(source, options, globals);
    result.warnings.forEach(function ({
        formatted_message
    }) {
        console.error(formatted_message);
    });
}());

'

• shell output

To JSLint entire directory in shell:

#!/bin/sh

# JSLint directory '.'

node jslint.mjs .

• shell output

Quickstart JSLint Report

To create a JSLint report in shell:

#!/bin/sh

printf "function foo() {console.log('hello world');}\n" > hello.js

# Create JSLint report from file 'hello.js' in shell.

node jslint.mjs \
    jslint_report=.artifact/jslint_report_hello.html \
    hello.js

• shell output

• screenshot file .artifact/jslint_report_hello.html

To create a JSLint report in javascript:

#!/bin/sh

node --input-type=module --eval '

/*jslint devel*/
import jslint from "./jslint.mjs";
import fs from "fs";
(async function () {
    let result;
    let source = "function foo() {console.log(\u0027hello world\u0027);}\n";

// Create JSLint report from 

 in javascript.

    result = jslint.jslint(source);
    result = jslint.jslint_report(result);
    result = `<body class="JSLINT_ JSLINT_REPORT_">\n${result}</body>\n`;

    await fs.promises.mkdir(".artifact/", {recursive: true});
    await fs.promises.writeFile(".artifact/jslint_report_hello.html", result);
    console.error("wrote file .artifact/jslint_report_hello.html");
}());

'

• shell output

• screenshot file .artifact/jslint_report_hello.html

Quickstart V8 Coverage Report

To create V8 coverage report from Node.js / Npm program in shell:

#!/bin/sh

git clone https://github.com/tryghost/node-sqlite3 node-sqlite3-sh \
    --branch=v5.0.11 \
    --depth=1 \
    --single-branch

cd node-sqlite3-sh
npm install

# Create V8 coverage report from program `npm run test` in shell.

node ../jslint.mjs \
    v8_coverage_report=../.artifact/coverage_sqlite3_sh/ \
        --exclude=tes?/ \
        --exclude=tes[!0-9A-Z_a-z-]/ \
        --exclude=tes[0-9A-Z_a-z-]/ \
        --exclude=tes[^0-9A-Z_a-z-]/ \
        --exclude=test/**/*.js \
        --exclude=test/suppor*/*elper.js \
        --exclude=test/suppor?/?elper.js \
        --exclude=test/support/helper.js \
        --include=**/*.cjs \
        --include=**/*.js \
        --include=**/*.mjs \
        --include=li*/*.js \
        --include=li?/*.js \
        --include=lib/ \
        --include=lib/**/*.js \
        --include=lib/*.js \
        --include=lib/sqlite3.js \
    npm run test

• shell output

• screenshot file .artifact/coverage_sqlite3_sh/index.html

• screenshot file .artifact/coverage_sqlite3_sh/lib/sqlite3.js.html

To create V8 coverage report from Node.js / Npm program in javascript:

```shell

!/bin/sh

git clone https://github.com/tryghost/node-sqlite3 node-sqlite3-js \ --branch=v5.0.11 \ --depth=1 \ --single-branch

cd node-sqlite3-js npm install

node --input-type=module --eval '

/jslint node/ import jslint from "../jslint.mjs"; (async function () {

// Create V8 coverage report from program npm run test in javascript.

await jslint.v8CoverageReportCreate({
    coverageDir: "../.artifact/coverage_sqlite3_js/",
    processArgv: [
        "--exclude=tes?/",
        "--exclude=tes[!0-9A-Z_a-z-]/",
        "--exclude=tes[0-9A-Z_a-z-]/",
        "--exclude=tes[^0-9A-Z_a-z-]/",
        "--exclude=test/**/*.js",
        "--exclude=test/suppor*/*elper.js",
        "--exclude=test/suppor?/?elper.js",
        "--exclude=te