Quote Block: Fix parsing a blockquote without a classname

[youknowriad]

This PR fixes parsing a blockquote without a classname, and returns 1 as the default styling for quotes without classnames.

[aduth]

With this, there's now three ways we're enforcing a default value for style.

• Explicitly return 1 from style parsing
• Return null from style parsing and fallback using || 1 in edit and save
• Destructure with style = 1 default in controls.isActive

I think we ought to consolidate on one. My preference would be toward returning undefined in the style parsing and using destructuring with default value.

[aduth]

e.g.

Explicit undefined:

style: ( node ) => {
	const value = attr( 'blockquote', 'class' )( node );
	if ( ! value ) {
		return;
	}

	const match = value.match( /\bblocks-quote-style-(\d+)\b/ );
	if ( ! match ) {
		return;
	}

	return Number( match[ 1 ] );
}

Implicit undefined:

style: ( node ) => {
	const value = attr( 'blockquote', 'class' )( node );
	if ( value ) {
		const match = value.match( /\bblocks-quote-style-(\d+)\b/ );
		if ( match ) {
			return Number( match[ 1 ] );
		}
	}
}

[youknowriad]

Sounds good to me, I'd go for the explicit one :)

[aduth]

This looks good and seems to simplify a fair bit on how we're we're using style 👍

[aduth]

Depending on how we want the quote block to be styled, should we always enforce the existence of a class, even if it's the "default" (first) style?

[youknowriad]

Probably, but I think it's worth dropping here to avoid having this bug another time?

[aduth]

Probably, but I think it's worth dropping here to avoid having this bug another time?

I don't feel strongly either way. We can keep it as you have here and if it becomes a point of confusion, reintroduce later.

[nylen]

This would be better handled with unit tests.