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eslint-plugin-html

eslint-plugin-html

Build Status

This ESLint plugin allows linting and fixing inline scripts contained in HTML files.

Migration to v3

If you are considering upgrading to v3, please read this guide.

Usage

Simply install via npm install --save-dev eslint-plugin-html and add the plugin to your ESLint configuration. See ESLint documentation.

Example:

{
    "plugins": [
        "html"
    ]
}

Note: by default, when executing the eslint command on a directory, only .js files will be linted. You will have to specify extra extensions with the --ext option. Example: eslint --ext .html,.js src will lint both .html and .js files in the src directory. See ESLint documentation.

XML support

This plugin parses HTML and XML markup slightly differently, mainly when considering CDATA sections:

  • in XML, any data inside a CDATA section will be considered as raw text (not XML) and the CDATA delimiter will be droped ;
  • in HTML, there is no such thing for <script> tags: the CDATA delimiter is considered as normal text and thus, part of the script.

Settings

Note: all settings can be written either as "html/key": value or in a nested object "html": { "key": value }

html/html-extensions

By default, this plugin will only consider files ending with those extensions as HTML: .erb, .handlebars, .hbs, .htm, .html, .mustache, .nunjucks, .php, .tag, .twig, .vue, .we. You can set your own list of HTML extensions by using this setting. Example:

{
    "plugins": [ "html" ],
    "settings": {
        "html/html-extensions": [".html", ".we"],  // consider .html and .we files as HTML 
    }
}

html/xml-extensions

By default, this plugin will only consider files ending with those extensions as XML: .xhtml, .xml. You can set your own list of XML extensions by using this setting. Example:

{
    "plugins": [ "html" ],
    "settings": {
        "html/xml-extensions": [".html"],  // consider .html files as XML 
    }
}

html/indent

By default, the code between <script> tags is dedented according to the first non-empty line. The setting html/indent allows to ensure that every script tags follow an uniform indentation. Like the indent rule, you can pass a number of spaces, or "tab" to indent with one tab. Prefix this value with a + to be relative to the <script> tag indentation. Example:

{
    "plugins": [ "html" ],
    "settings": {
        "html/indent": "0",   // code should start at the beginning of the line (no initial indentation). 
        "html/indent": "+2",  // indentation is the <script> indentation plus two spaces. 
        "html/indent": "tab", // indentation is one tab at the beginning of the line. 
    }
}

html/report-bad-indent

By default, this plugin won't warn if it encounters a problematic indentation (ex: a line is under indented). If you want to make sure the indentation is correct, use the html/report-bad-indent in conjunction with the indent rule. Pass "warn" or 1 to display warnings, "error" or 2 to display errors. Example:

{
    "plugins": [ "html" ],
    "settings": {
        "html/report-bad-indent": "error",
    }
}

html/javascript-mime-types

By default, the code between <script> tags is considered as JavaScript code only if there is no type attribute or if its value matches the pattern /^(application|text)\/(x-)?(javascript|babel|ecmascript-6)$/i. You can customize the types that should be considered as JavaScript by providing one or multiple MIME types. If a MIME type starts with a /, it will be considered as a regular expression. Example:

{
    "plugins": [ "html" ],
    "settings": {
        "html/javascript-mime-types": ["text/javascript", "text/jsx"],  // also use script tags with a "text/jsx" type attribute 
        "html/javascript-mime-types": "/^text\\/(javascript|jsx)$/",    // same thing 
    }
}

Troubleshooting

Linting templates (or PHP)

eslint-plugin-html won't evaluate or remove your template markup. If you have template markup in your script tags, the resulting script may not be valid JavaScript, so ESLint will fail to parse it.

One possible hacky workaround to make sure the code is valid JavaScript is to put your template markup inside a comment. When the template is rendered, the generated JS code must start with a new line, so it will be written below the comment. PHP example:

<script>
var mydata;
// <?= "\n mydata = " . json_encode($var) . ";" ?>
console.log(mydata);
</script> 

Linting VUE files

Initially, eslint-plugin-vue was using eslint-plugin-html to lint code inside script tags. Since v3, eslint-plugin-vue is using its own parser, so it is incompatible with eslint-plugin-html. You should remove eslint-plugin-html from your dependencies if you still have this.