eslint-plugin-smarter-tabs

🎓 eslint-plugin-smarter-tabs

This plugin aims to enforce the usage of smart tabs, as defined in the emacs wiki:

• Tabs are only used at the beginning of lines. Everything else, like ASCII art and tables, should be formatted with spaces.
• Tabs are only used for expressing the indentation level. One tab per “block” — any remaining whitespace is spaces only.

To accomplish this, the plugin exports a single rule which issues a report in three cases:

• The line contains an inline tabulation:

Valid	Invalid
const foo = true; const foobar = false;	const foo———𝈷= true; const foobar = false;

• The line use spaces for indentation. This happens when a line is indented with spaces or starts with tabs followed by spaces, and its indentation level is different than the one of its block:

Valid	Invalid
function foo(bar) { ————𝈷return (bar === undefined) ————𝈷 ? 'foo'; ————𝈷 : 'bar'; }	function foo(bar) { ————𝈷return (bar === undefined) ————𝈷————𝈷 ? 'foo'; ————𝈷————𝈷 : 'bar'; }

• The line has a mismatched indentation level. This happens when the indentation level of the line is greater than the one of the line before it by two or more:

Valid	Invalid
if (baz) { ————𝈷let p = { x: 1, ————𝈷 y: 2, ————𝈷 z: 3, ————𝈷}; }	if (baz) { ————𝈷let p = { x: 1, ————𝈷————𝈷————𝈷y: 2, ————𝈷————𝈷————𝈷z: 3, ————𝈷}; }

Installation

npm i -D eslint-plugin-smarter-tabs

Usage

This plugin exports a single rule called smarter-tabs that you can use in your .eslintrc.json or eslintrc.js:

{
	"plugins": [
		"smarter-tabs"
	],

	"rules": {
		"smarter-tabs/smarter-tabs": "warn"
	}
}

If you use the eslint:recommended preset, you may also want to disable the no-mixed-spaces-and-tabs rule as it might clash with this plugin:

{
	"rules": {
		"no-mixed-spaces-and-tabs": "off",
		"smarter-tabs/smarter-tabs": "warn"
	}
}

Or you could pass it the smart-tabs options:

{
	"rules": {
		"no-mixed-spaces-and-tabs": ["warn", "smart-tabs"],
		"smarter-tabs/smarter-tabs": "warn"
	}
}

Changelog

See the full changelog here.

License

This software is distributed under the ISC license.