Replacing `$this` with `$block` in templates is not universally safe / correct

[fredden]

Preconditions

1. In a template (.phtml file), make use of $this->helper(SomeClass:class);. For example, https://github.com/magento/magento2/blob/2.4.4/app/code/Magento/Catalog/view/frontend/templates/product/listing.phtml#L20
2. Magento Coding Standard version 25

Steps to reproduce

1. Run phpcbf --standard=Magento2 on template

Expected result

1. Template works the same as before auto-fixes are applied.

Actual result

1. Exception is throw: Invalid method Vendor\Module\Block\SomeBlockClass\Interceptor::helper

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[Nuranto]

@fredden have a look at https://github.com/magento/magento-coding-standard/issues/156

[fredden]

@Nuranto thanks for your feedback.

I have no problem with the warning / message that says that helpers are deprecated / should not be used. I have no problem with the warning / message that says that one should use $block->getThing() not $this->getThing() in templates. I have no problem with the auto-fix of $this->getThing() to $block->getThing().

This bug is for when $this->helper() gets replaced automatically with $block->helper(), which results in a broken template. (The automatic replacement of $this->getThing() with $block->getThing() is fine and the template works just fine with this change.)

[Nuranto]

I understand, and agree but my point was that they probably won’t do anything about it since they consider this is a not a correct approach.

For my projects, I simply run the fixer with that rule excluded. But of course that means it won’t fix other $this cases..

[fredden]

That's what we've had to do as well (remove/exclude this rule from the fixer).