JSLint, The JavaScript Code Quality and Coverage Tool

Status

Branch	master (v2024.6.28)	beta (Web Demo)	alpha (Development)
CI
Coverage
Demo
Artifacts

Web Demo
Web Demo Archived
Quickstart Install
Quickstart JSLint Report
- To create a JSLint report in shell:
- To create a JSLint report in javascript:
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:
Quickstart JSLint in CodeMirror
Quickstart JSLint in Vim
Quickstart JSLint in VSCode
Documentation
Package Listing
Changelog
License
Devops Instruction

Web Demo

https://www.jslint.com

Web Demo Archived

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

screenshot

To run `jslint.mjs` in shell:

#!/bin/sh

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

node jslint.mjs hello.js

shell output

screenshot

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 <source> and print <formatted_message>.

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

'

shell output

screenshot

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 <source> and print <formatted_message>.

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

'

shell output

screenshot

To JSLint entire directory in shell:

#!/bin/sh

# JSLint directory '.'

node jslint.mjs .

shell output

screenshot

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

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 <source> 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

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

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:

#!/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=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

screenshot file .artifact/coverage_sqlite3_js/index.html

screenshot file .artifact/coverage_sqlite3_js/lib/sqlite3.js.html

Quickstart JSLint in CodeMirror

Download and save jslint.mjs, jslint_wrapper_codemirror.js to file.

Edit, save, and serve example html-file below:


<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>CodeMirror: JSLint Demo</title>

<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/codemirror/5.65.10/codemirror.css">
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/codemirror/5.65.10/addon/lint/lint.css">
<script defer src="https://cdnjs.cloudflare.com/ajax/libs/codemirror/5.65.10/codemirror.js"></script>
<script defer src="https://codemirror.net/mode/javascript/javascript.js"></script>
<script defer src="https://cdnjs.cloudflare.com/ajax/libs/codemirror/5.65.10/addon/lint/lint.js"></script>

<script type="module" src="https://github.com/jslint-org/jslint/raw/beta/jslint.mjs?window_jslint=1"></script>
<script defer src="https://github.com/jslint-org/jslint/raw/beta/jslint_wrapper_codemirror.js"></script>

CodeMirror: JSLint Demo

This demo will auto-lint the code below, and auto-generate a report as you type.

3. Live example at https://www.jslint.com/jslint_wrapper_codemirror.html

[![screenshot](https://jslint-org.github.io/jslint/branch-beta/.artifact/screenshot_browser__2fjslint_2fbranch-beta_2fjslint_wrapper_codemirror.html.png)](https://jslint-org.github.io/jslint/jslint_wrapper_codemirror.html)

<br><br>
# Quickstart JSLint in Vim
1. Download and save [`jslint.mjs`](https://www.jslint.com/jslint.mjs), [`jslint_wrapper_vim.vim`](https://www.jslint.com/jslint_wrapper_vim.vim) to directory `~/.vim/`
2. Add vim-command `:source ~/.vim/jslint_wrapper_vim.vim` to file `~/.vimrc`
    - If above files were saved to custom-directory, then use that directory instead, e.g.:
        - save [`jslint.mjs`](https://www.jslint.com/jslint.mjs), [`jslint_wrapper_vim.vim`](https://www.jslint.com/jslint_wrapper_vim.vim) to directory `~/vimfiles/`
        - vim-command `:source ~/vimfiles/jslint_wrapper_vim.vim`
3. Vim can now jslint files (via nodejs):
    - with vim-command `:SaveAndJslint`
    - with vim-key-combo `<Ctrl-S> <Ctrl-J>`
- screenshot

[![screenshot](asset_image_jslint_wrapper_vim.png)](https://www.jslint.com/jslint_wrapper_vim.vim)

<br><br>
# Quickstart JSLint in VSCode
1. In VSCode, search and install extension [`vscode-jslint`](https://marketplace.visualstudio.com/items?itemName=jslint.vscode-jslint)
2. In VSCode, while editing a javascript file:
    - right-click context-menu and select `[JSLint - Lint File]`
    - or use key-binding `[Ctrl + Shift + J], [L]`
    - or use key-binding `[ Cmd + Shift + J], [L]` for Mac
- screenshot

[![screenshot](https://jslint-org.github.io/jslint/asset_image_jslint_wrapper_vscode.png)](https://marketplace.visualstudio.com/items?itemName=jslint.vscode-jslint)

<br><br>
# Documentation

- [jslint.mjs](jslint.mjs) contains the jslint function. It parses and analyzes a source file, returning an object with information about the file. It can also take an object that sets options.

- [index.html](index.html) runs the jslint.mjs function in a web page.

JSLint can be run anywhere that JavaScript (or Java) can run.

The place to express yourself in programming is in the quality of your ideas and
the efficiency of their execution. The role of style in programming is the same
as in literature: It makes for better reading. A great writer doesn't express
herself by putting the spaces before her commas instead of after, or by putting
extra spaces inside her parentheses. A great writer will slavishly conform to
some rules of style, and that in no way constrains her power to express herself
creatively. See for example William Strunk's The Elements of Style
[https://www.crockford.com/style.html].

This applies to programming as well. Conforming to a consistent style improves
readability, and frees you to express yourself in ways that matter. JSLint here
plays the part of a stern but benevolent editor, helping you to get the style
right so that you can focus your creative energy where it is most needed.

<br><br>
### API Doc
- https://www.jslint.com/apidoc.html

[![screenshot](https://jslint-org.github.io/jslint/branch-beta/.artifact/screenshot_browser__2f.artifact_2fapidoc.html.png)](https://www.jslint.com/apidoc.html)

<br><br>
### Directive `/*jslint*/`

<br>

##### `/*jslint beta*/`

```js
/*jslint beta*/
// Enable experimental warnings.
// Warn if global variables are redefined.
// Warn if const / let statements are not declared at top of function or
//    script, similar to var statements.
// Warn if const / let / var statements are not declared in ascii-order.
// Warn if named-functions are not declared in ascii-order.
// Warn if cases in switch-statements are not in ascii-order.

`/jslint bitwise/`

/*jslint bitwise*/
// Allow bitwise operator.

let foo = 0 | 1;

`/jslint browser/`

/*jslint browser*/
// Assume browser environment.

localStorage.getItem("foo");

`/jslint convert/`

/*jslint convert*/
// Allow conversion operator.

let foo = new Date() + "";
let bar = !!0;

`/jslint couch/`

/*jslint couch*/
// Assume CouchDb environment.

registerType("text-json", "text/json");

`/jslint devel/`

/*jslint devel*/
// Allow console.log() and friends.

console.log("hello");

`/jslint eval/`

/*jslint eval*/
// Allow eval().

eval("1");

`/jslint fart/`

/*jslint fart*/
// Allow complex fat-arrow.

let foo = async ({bar, baz}) => {
    return await bar(baz);
};

`/jslint for/`

/*jslint for*/
// Allow for-loop.

function foo() {
    let ii;
    for (ii = 0; ii < 10; ii += 1) {
        foo();
    }
}

`/jslint getset/`

/*jslint getset, this, devel*/
// Allow get() and set().

let foo = {
    bar: 0,
    get getBar() {
        return this.bar;
    },
    set setBar(value) {
        this.bar = value;
    }
};
console.log(foo.getBar); // 0
foo.setBar = 1;
console.log(foo.getBar); // 1

`/jslint indent2/`

/*jslint indent2*/
// Use 2-space indent.

function foo() {
  return;
}

`/jslint long/`

/*jslint long*/
// Allow long lines.

let foo = "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa";

`/jslint node/`

/*jslint node*/
// Assume Node.js environment.

require("fs");

`/jslint nomen/`

/*jslint nomen*/
// Allow weird property name.

let foo = {};
foo._bar = 1;

`/jslint single/`

/*jslint single*/
// Allow single-quote strings.

let foo = '';

`/jslint subscript/`

/*jslint subscript*/
// Allow identifiers in subscript-notation.

let foo = {};
foo["bar"] = 1;

`/jslint this/`

/*jslint this*/
// Allow 'this'.

function foo() {
    return this;
}

`/jslint trace/`

/*jslint trace*/
// Include jslint stack-trace in warnings.

console.log('hello world');
/*
1. Undeclared 'console'.
console.log('hello world');
Error
    at warn_at (...)
    at warn (...)
    at lookup (...)
    at pre_v (...)
    at jslint.mjs
2. Use double quotes, not single quotes.
console.log(...);
Error
    at warn_at (...)
    at lex_string (...)
    at lex_token (...)
    at jslint_phase2_lex (...)
    at Function.jslint (...)
    at jslint.mjs
*/

`/jslint unordered/`

/*jslint unordered*/
// Allow unordered cases, params, properties, variables, and exports.

let foo = {bb: 1, aa: 0};

function bar({
    bb = 1,
    aa = 0
}) {
    return aa + bb;
}

export {
    foo,
    bar
};

`/jslint white/`

/*jslint white*/
// Allow messy whitespace.

let foo = 1; let bar = 2;

Directive `/global/`

/*global foo, bar*/
// Declare global variables foo, bar.

foo();
bar();

Directive `/property/`

/*property foo, bar*/
// Restrict property-access to only .foo, .bar.

let aa = {bar: 1, foo: 2};

Directive `/jslint-disable/.../jslint-enable/`

/*jslint-disable*/

JSLint will ignore and treat this region as blank-lines.
Syntax error.

/*jslint-enable*/

Directive `//jslint-ignore-line`

// JSLint will ignore non-fatal warnings at given line.

eval("1"); //jslint-ignore-line

Package Listing

Changelog

Full CHANGELOG.md

License

JSLint is under Unlicense License.
CodeMirror editor is under MIT License.
Function v8CoverageListMerge is derived from MIT Licensed v8-coverage.

Devops Instruction

pull-request merge

find highest issue-number at https://github.com/jslint-org/jslint/issues/, https://github.com/jslint-org/jslint/pulls/, and add +1 to it for PR-xxx
shGitPullrequest beta beta
- verify ci-success for origin-branch-alpha
- https://github.com/kaizhu256/jslint/actions
git push upstream alpha -f
- verify ci-success for upstream-branch-alpha
- https://github.com/jslint-org/jslint/actions
goto https://github.com/jslint-org/jslint/compare/beta...kaizhu256:jslint:branch-p2024.6.23
click Create pull request
input Add your description here... with:
```
Fixes #xxx.
```

This PR will ...

this PR will additionally:

``` - verify `commit into jslint-org:beta` - click `Create pull request` - verify ci-success for pull-request - https://github.com/jslint-org/jslint/actions/workflows/on_pull_request.yml - wait awhile before continuing ... - click `Rebase and merge` - verify ci-success for upstream-branch-beta - https://github.com/jslint-org/jslint/actions - `shGitPullrequestCleanup` - verify ci-success for origin-branch-alpha - https://github.com/kaizhu256/jslint/actions - `git push upstream alpha -f` - verify ci-success for upstream-branch-alpha - https://github.com/jslint-org/jslint/actions - click `Delete branch`

### branch-master commit - `shGitPullrequest master beta` - verify ci-success for origin-branch-alpha - https://github.com/kaizhu256/jslint/actions - `git push upstream alpha -f` - verify ci-success for upstream-branch-alpha - https://github.com/jslint-org/jslint/actions - goto https://github.com/jslint-org/jslint/compare/beta...kaizhu256:jslint:branch-v2024.6.28 - click `Create pull request` - input `Add a title` with: `# v20yy.mm.dd` - input `Add a description` with: ``` - - ``` - verify `commit into jslint-org:beta` - click `Create pull request` - verify ci-success for pull-request - https://github.com/jslint-org/jslint/actions/workflows/on_pull_request.yml - wait awhile before continuing ... - click `Rebase and merge` - verify ci-success for upstream-branch-beta - https://github.com/jslint-org/jslint/actions - `shGitPullrequestCleanup` - verify ci-success for origin-branch-alpha - https://github.com/kaizhu256/jslint/actions - `git push upstream alpha -f` - verify ci-success for upstream-branch-alpha - https://github.com/jslint-org/jslint/actions - click `Delete branch` - `git push origin beta:master` - verify ci-success for origin-branch-master - https://github.com/kaizhu256/jslint/actions - `git push upstream beta:master` - verify ci-success for upstream-branch-master - https://github.com/jslint-org/jslint/actions

### branch-master publish - `git push upstream beta:master` - verify ci-success for upstream-branch-master - https://github.com/jslint-org/jslint/actions - goto https://github.com/jslint-org/jslint/releases/new - input `Choose a tag` with: `v20yy.mm.dd` - click `Create new tag: v20yy.mm.dd on publish` - verify correct-year `20yy` - select `Target: master` - select `Previous tag:auto` - input `Release title` with: `v20yy.mm.dd - ` - input `Describe this release` with: ``` - - ``` - click `Generate release notes` - click `Set as the latest release` - click `Preview` and review - click `Publish release` - verify ci-success for upstream-branch-publish - https://github.com/jslint-org/jslint/actions - verify email-notification `Successfully published @jslint-org/jslint@20yy.mm.dd`

### vscode-jslint publish - goto https://github.com/jslint-org/jslint/tree/gh-pages/branch-beta/.artifact/jslint_wrapper_vscode - click `vscode-jslint-20yy.mm.dd.vsix` - click `Raw` to download - goto https://marketplace.visualstudio.com/manage/publishers/jslint - right-click `Update` - upload downloaded file `vscode-jslint-20yy.mm.dd.vsix` - click 'Upload' - verify email-notification `[Succeeded] Extension publish on Visual Studio Marketplace - vscode-jslint`

jslint-org / jslint

readme

JSLint, The JavaScript Code Quality and Coverage Tool

Status

Table of Contents

Web Demo

Web Demo Archived

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:

Quickstart JSLint Report

To create a JSLint report in shell:

To create a JSLint report in javascript:

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:

Quickstart JSLint in CodeMirror

CodeMirror: JSLint Demo

This demo will auto-lint the code below, and auto-generate a report as you type.

/*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

Package Listing

Changelog

License

Devops Instruction

pull-request merge

To run `jslint.mjs` in shell:

To import `jslint.mjs` in ES Module environment:

To import `jslint.mjs` in CommonJS environment:

`/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`