Blocks: fix block variation name checking

[meteorlxy]

What?

When registering block variations in array:

registerBlockVariation( 'core/variation-block', [
	{
		name: 'variation-name',
		title: 'Variation Title',
		description: 'Variation description',
	},
	{
		name: 'variation-name-2',
		title: 'Variation Title 2',
		description: 'Variation description 2',
	},
] );

There would always have a warning in console:

Why?

Fix the wrong warning

How?

Check if the variation param is an array or not

Testing Instructions

Testing Instructions for Keyboard

Screenshots or screencast

[github-actions]

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Co-authored-by: meteorlxy <meteorlxy@git.wordpress.org>
Co-authored-by: Mamaduka <mamaduka@git.wordpress.org>

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[Mamaduka]

Thanks for contributing, @meteorlxy!

As the function name suggests, the registerBlockVariation isn't meant to register multiple variations. The fact that it was able to do so is an unaccounted side-effect.

I think we should first consider whether we want to support or discourage this behavior.

[meteorlxy]

@Mamaduka Oh didn't know that.

The types definition in the @types/wordpress__blocks package is the key reason that why we thought array is supported:

https://github.com/DefinitelyTyped/DefinitelyTyped/blob/d5a5c3b0ef50b7277750ed631c3d640b27272143/types/wordpress__blocks/api/registration.d.ts#L192-L198

Then maybe creating official typings would help discourage this behavior

[Mamaduka]

JSDoc states that it accepts a variation object:

gutenberg/packages/blocks/src/api/registration.js

Lines 702 to 703 in 57c9c69

	* @param {string} blockName Name of the block (example: “core/columns”).
	* @param {WPBlockVariation} variation Object describing a block variation.