Static versioning and styles minification break email fonts styles

[Igloczek]

Preconditions

Enabled static versioning and styles minification in production mode.

Steps to reproduce

1. Make an order or any other action that will send an email.
2. Run static-content:deploy or make and application deployment
3. Open previous email.

Expected result

1. Your email should have proper styles including fonts (check console).

Actual result

1. email-fonts.min.css generated by static-content:deploy isn't loaded, b/c email template is requesting for email-fonts.css. It's hardcoded in /web/css/source/_email-extend.less of Blank and Luma themes.
2. Even if email-fonts.css will exist, running static-content:deploy or making an whole application deployment, will make path to this file unaccessible due to static version change.

[AirmanAJK]

My fix for this was to add "email" to the config setting 'dev/css/minify_exclude'. Whenever css filenames are generated, this config value (if present) is split by line break (\n) and compared with the file to potentially add ".min" to using a contains function. If any matches are found, no .min is added to the filename.

I had other problems with css and javascript files getting minified so that right now my two exclude configs look like this:

'dev/js/minify_exclude' : 'api/checkout\ntiny_mce\neditor'
'dev/css/minify_exclude' : 'tiny_mce\neditor\nemail'

This fixes several issues while minifying:

1. Paypal's external checkout.js file (which has no min version and is downloaded remotely) being broken.
2. Static email css imports are improperly referenced (as you've seen).
3. TinyMCE intermittently going crazy with not finding extensions in the admin area.

An official fix here is tricky because these config values are a combination of settings from different areas, so an extension can't simply append it's own addition to it using the normal config files. You may be stuck with manually managing these settings in the database. Magento devs will probably have to rethink the exception lists for these resources, because there is a clear need for it.

[xmav]

@Igloczek Thanks for reporting this issue.
We've created internal ticket MAGETWO-64085 to address this issue.

[PieterCappelle]

Any update on this?

[tigerx7]

We just updated to 2.1.6 recently and ran into this problem. Even though we had CSS Minify set to false in admin, CSS was still being minified and breaking styles in the transactional emails. Digging into it, seems the issue is with the way the less parser is being used.

In https://github.com/magento/magento2/blob/develop/lib/internal/Magento/Framework/Css/PreProcessor/Adapter/Less/Processor.php#L73, the compress option is being set by if Magento is in developer mode or not... which clearly defies the purpose of the CSS minify option in admin since almost all CSS will be running through less.

We just removed the compress option from being passed on to less.php in Processor.php which resulted in non-minified CSS and correctly began styling the outgoing transactional emails.

[CNanninga]

Intrinsically related to the same cause is the fact that some inline styles are missing as well. Same factors (always happens when the forced minification takes place in production mode).

Normal email styles when static content deployment was done in developer mode: https://files.classyllama.com/cf99354a/screenshots/Your_Main_Website_Store_order_confirmation_-_chris.nanningaclassyllama.com_-_Classy_Llama_Studios_LLC_Mail_2017-07-27_09-23-15.jpg

The way it looks when deployment was done in production mode:
https://files.classyllama.com/cf99354a/screenshots/Your_Main_Website_Store_order_confirmation_-_chris.nanningaclassyllama.com_-_Classy_Llama_Studios_LLC_Mail_2017-07-27_09-59-39.jpg

In the second example, the style sheets were minified even though minification is disabled, and the missing styles are those that should be injected inline.

[xmav]

To fix issue just bump version of pelago/emogrifier to 1.2.0 in composer.json