regex-empty-conditional-comments^2.0.1

Regular expression for matching HTML empty conditional comments

Install via npm

npm i regex-empty-conditional-comments

This package is ESM only: Node 12+ is needed to use it and it must be imported instead of required:

import { emptyCondCommentRegex } from "regex-empty-conditional-comments";

If you need a legacy version which works with require, use version 1.11.0:

"regex-empty-conditional-comments": "1.11.0",

Install as a script, via CDN

Put this in your HTML:

<script src="https://cdn.jsdelivr.net/npm/regex-empty-conditional-comments/dist/regex-empty-conditional-comments.umd.js"></script>

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

const { emptyCondCommentRegex } = regexEmptyConditionalComments;

Trivia

This program has 25 assertions in its unit tests. That's less than all unit test assertions' median (48) and less than geometric mean (70).

In monorepo, one other package, email-comb, consumes this package.

Quick Take

import { strict as assert } from "assert";
import { emptyCondCommentRegex } from "regex-empty-conditional-comments";

// empty comment which was meant to target Outlook-only
assert.equal(
  emptyCondCommentRegex().test(`<!--[if !mso]>
<![endif]-->`),
  true
);

// empty comment which was meant to target non-Outlook-only
assert.equal(
  emptyCondCommentRegex().test(`<!--[if !mso]><!-- -->
<!--<![endif]-->`),
  true
);

assert.equal(
  emptyCondCommentRegex().test(`<!--[if !mso]><!-- -->
<meta http-equiv="X-UA-Compatible" content="IE=edge" />
<!--<![endif]-->`),
  false
);

assert.equal(
  emptyCondCommentRegex()
    .test(`<!--[if gte mso 9]><xml>
<o:OfficeDocumentSettings>
<o:AllowPNG/>
<o:PixelsPerInch>96</o:PixelsPerInch>
</o:OfficeDocumentSettings>
</xml><![endif]-->`),
  false
);

assert.equal(
  emptyCondCommentRegex().exec(
    "<html><!--[if !mso]><![endif]--><title>"
  )[0],
  "<!--[if !mso]><![endif]-->"
);

assert.deepEqual(
  `<html> <!--[if !mso]><![endif]--> <title>text</title> <!--[if gte mso 9]>
<xml>
<![endif]-->`.match(emptyCondCommentRegex()),
  ["<!--[if !mso]><![endif]-->"]
);