rfc:php8_assertions

PHP RFC: Your Title Here

Introduction

In PHP 7.0, the assert statement received some enhancements. Notably, it added the ability to throw exceptions on failures (but off by ini default) and the code to assert could now be directly given to assert, instead of only through a string argument. In 7.2, the string argument was officially deprecated, and support has been removed from master for PHP 8. The assert_options function has been discouraged in the official documentation for PHP 7. This RFC proposes the continued cleanup of assert behavior.

Proposal

This RFC proposes that:

1. The ini setting ''assert.exception'' defaults to 1, meaning that exceptions will be thrown on an assertion failure instead of emitting a warning. 
2. The function ''assert_options'' is officially deprecated in code, not just discouraged in documentation.

Since a failing assertion means that the program is in an unexpected state, throwing an exception or otherwise exiting are the only viable actions; continuing after emitting a warning is unwise and further issues in the program runtime are expected to occur. In the worst case, the program will exhibit different behavior without any other symptoms; if the the logs are not checked, it is possible this bug might go unnoticed. Changing the default to now throw exceptions will probably leave programs using the default settings in a more correct state than they were prior to this change.

Backward Incompatible Changes

The ini setting assert.exception defaults to 1, meaning that exceptions will be thrown on an assertion failure instead of emitting a warning.

Proposed PHP Version(s)

This RFC targets PHP 8.0.

RFC Impact

php.ini Defaults

assert.exceptions:

  • hardcoded default value: 1
  • php.ini-development value: 1, and no longer commented out
  • php.ini-production value: 1, and no longer commented out

Open Issues

Make sure there are no open issues when the vote starts!

Unaffected PHP Functionality

List existing areas/features of PHP that will not be changed by the RFC.

This helps avoid any ambiguity, shows that you have thought deeply about the RFC's impact, and helps reduces mail list noise.

Future Scope

This section details areas where the feature might be improved in future, but that are not currently proposed in this RFC.

Proposed Voting Choices

This vote will be a single yes or no vote to accept the RFC, requiring two-thirds of votes to be “yes” to pass.

Patches and Tests

There is no patch at this time. It is an incredibly small patch, so I am not worried about not having one yet.

Implementation

After the project is implemented, this section should contain

  1. the version(s) it was merged into
  2. a link to the git commit(s)
  3. a link to the PHP manual entry for the feature
  4. a link to the language specification section (if any)

References

Links to external references, discussions or RFCs

Rejected Features

Keep this updated with features that were discussed on the mail lists.

rfc/php8_assertions.txt · Last modified: 2019/10/28 11:28 by levim