Block transforms: single Blocks shouldn't allow transforms to the same Block. Avoid block-specific behaviours

[getdave]

Currently, the block transform logic prevents a single group block from being transformed into another core group block.

https://github.com/WordPress/gutenberg/pull/14908/files/5dd34524c2a6bdd81b399d959ad71636ef0c3501#diff-a5c77b070da74373cd1d937dee3a77eaR150

In pursuit of avoiding block-specific behaviours here, we should see if this is this more about preventing a block from being transformed into itself. In which case we could make this condition apply to any block type and not specifically the group block?

Originally posted by @aduth in #14908

[draganescu]

What is this issue about, I am having trouble understanding it, even after visiting the original PR :)

[aduth]

The implementation has changed slightly since the issue was originally created, but I believe the goal is the same as it once was: A block should not be allowed to be transformed into its own block type.

This logic:

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

Lines 169 to 177 in aa44b76

	// Don't allow single Grouping blocks to be transformed into
	// a Grouping block.
	if (
	! isMultiBlock &&
	isContainerGroupBlock( sourceBlock.name ) &&
	isContainerGroupBlock( transform.blockName )
	) {
	return false;
	}

Can be simplified to one where the source block type and transform candidate block type are compared.

Something like:

// Don't allow a transform to the same block type.
if ( ! isMultiBlock && sourceBlock.name === transform.blockName ) {
	return false;
}

[jordesign]

@getdave @aduth - just looping back through old issues, is this still relevant?

[getdave]

Seems very old. I think we can close it out.