is-html-attribute-closing^2.1.3

Is a character on a given index a closing of an HTML attribute?

Install via npm

npm i is-html-attribute-closing

Consume via a require():

const { isAttrClosing } = require("is-html-attribute-closing");

or as an ES Module:

import { isAttrClosing } from "is-html-attribute-closing";

Install as a script, via CDN

Put this in your HTML:

<script src="https://cdn.jsdelivr.net/npm/is-html-attribute-closing/dist/is-html-attribute-closing.umd.js">

Then, you’ll get a global variable isHtmlAttributeClosing in your Global object and you consume it like this:

const { isAttrClosing } = isHtmlAttributeClosing;

Trivia

This program has 2,917 assertions in its unit tests. That's more than all unit test assertions' median (47) and more than geometric mean (75).

In monorepo, one other package, codsen-tokenizer, consumes this package.

§ Quick Take

import { strict as assert } from "assert";
import { isAttrClosing } from "dist/is-html-attribute-closing.esm";

const str = `<a href="zzz" target="_blank" style="color: black;">`;

// <a href="zzz" target="_blank" ...
//                      ^
//                  index 21

// <a href="zzz" target="_blank" ...
//                             ^
//                         index 28

assert.equal(
  isAttrClosing(
    str, // reference string
    21, // known opening (or in absence of a quote, a start of a value)
    28 // we ask, is this a closing on the attribute?
  ),
  true // the answer
);

⬆ back to top

§ Examples

⬆ back to top

§ Purpose

This program detects, is a character at a given index in a given string being a closing of an attribute. In healthy code, that's normally a double quotes character.

This program is aimed at fixing seriously broken HTML code — missing closing quotes, mismatching closing quotes, swapped quotes and unencoded "content" quotes as a part of attribute's value.

It's driving the codsen-tokenizer which in turn powers codsen-parser which in turn powers emlint.

For healthy HTML code, however, finding the closing double quotes is a trivial task.

⬆ back to top

§ API - Input

isAttrClosing(
  str,
  idxOfAttrOpening,
  isThisClosingIdx
)

In other words, function which takes three arguments:

Input argument	Key value's type	Obligatory?	Description
`str`	String	yes	The input string of zero or more characters
`idxOfAttrOpening`	Natural number or zero	yes	Index of an opening quote of an attribute
`isThisClosingIdx`	Natural number	yes	Index we ask program to evaluate, is it a closing quote

This program does not throw. It just returns false.

If anything is wrong with the input arguments, the program returns false. It never throws. That's because it's to be used inside other programs. Idea is, proper algorithms that will use this program will "care" only about the truthy case: does the given quote pass as a closing-one. Crappy input arguments yields false, happy days, consuming algorithms continue whatever dodgy journeys they have been making.

We don't throw errors in this program.

⬆ back to top