--- title: "Exakat 1.5.3 review" url: https://www.exakat.io/exakat-1-5-3-review/ date: 2018-11-13 modified: 2020-10-06 author: "dams" description: "[caption id=\"attachment_4434\" align=\"alignleft\" width=\"300\"] Exakat 1.5.3 review[/caption] Exakat 1.5.3 Review Exakat 1.5.4 add more after-coding review for your code : after suggesting upgrading visibility on properties, it now checks class..." categories: - "Company" tags: - "classic trap" - "Exakat" - "generator" - "Yield" image: https://www.exakat.io/wp-content/uploads/2018/11/poppy.320.jpg word_count: 1308 --- # Exakat 1.5.3 review [![](https://178.62.231.40/wp-content/uploads/2018/11/poppy.320-300x300.jpg)](https://178.62.231.40/wp-content/uploads/2018/11/poppy.320.jpg)Exakat 1.5.3 review # Exakat 1.5.3 Review Exakat 1.5.4 add more after-coding review for your code : after suggesting upgrading visibility on properties, it now checks class candidates for `final` and `abstract` keyword. As you can guess, a class won't be a candidate for them at the same time. We also include more review of generators, including the PHP classic trap with `iterator_to_array()`, and code improvement with `yield from`. I love it when the Exakat 1.5.3 review comes together. ## Use Yield From `Yield from` was introduced in PHP 7. It is a delegation keyword for `yield` : the yielding will be handed to another function or method, and when this delegated yield has been finished, the next will resume. This means that `yield from` is basically a `foreach` loop for a designated generator, and may be used just like that : ``` ``` ``` ``` Note that `yield from` works with any `Traversable` object and arrays, on top of of other `Generator`. This means that the following are basically the same : ``` ``` ``` ``` It is probably not worth turning a foreach on array() into a generator, but if the code is juggling with several sources of data, it is very convenient to build such a generator. Using `yield from` not only hides the foreach loop, but it is also faster to execute. ## Beware of iteratortoarray() The `yield` keyword was introduced in PHP 5.5, to build generators. Those are used in foreach loops, and produce one value each time. To build an array from a generator, there is the convenient function `iterator_to_array()`, which collects all the values into one array, saving the call of a foreach(). ``` ``` ``` ``` As the [PHP manual](http://php.net/manual/en/language.generators.syntax.php#control-structures.yield.from) says, the `yield` keyword provides automatic keys but doesn't reset those when calling `yield from`. As such, mixing `yield` and `yield from` in the same generator is bound to lead to overwrite values in the final array. Solutions to this problem include : using [array_merge](http://php.net/manual/en/function.array-merge.php) to merge the arrays after using [iterator*to*array](http://php.net/manual/en/function.iterator-to-array.php); using keys when yielding. ``` ``` ``` ``` In this example, we simply reuse the value as key, and end up with distinct keys. If real code, when generators are arbitrarily combined, merging the arrays after the call to iterator*to*array() is a better idea. Thanks to [Holger Woltersdorf](https://twitter.com/hollodotme) for running into [it](https://twitter.com/hollodotme/status/1057917774759165952) ## Final or abstract after the code `final` and `abstract` are two keywords that apply to classes and methods. They signal classes that can't or must be extended, respectively. A `final` class can't be found as `extends`, and `abstract` classes must be `extends`. They are most often set at conception time, when the architect of the code has a broad view over it, and has freedom to add restrictions inside the code. When code conception is lightly enforced, or if architecture is grown organically, the code will be written without those keywords. How can we check if those keywords are applicable ? Since the code is already written, we simply have to reverse the logic of the rule : a `final` class is a class that is never extended, but instantiated; an `abstract` class is a class that is extended, but never instantiated directly. ``` ``` ``` ``` Please, be gentle with this example : it is small, for editing purposes. On the other hand, reviewing a 2000 class-strong application to check which are extended and which are instantiated is usually a daunting task : as such, it is often delayed until never done. All this is actually a good task for static analysis. Exakat collects all those operations across the entire repository, and report both situation in the Ambassador report (the default report). Here, you'll find every class that may be upgraded to `final` or `abstract`. The red stars mention possible upgrades by using `final` or `abstract` keywords; The green stars mention a valid absence of the option (an extended class, that can't be final, for example); The absence of star reports currently configured classes : good job. Is it enough to decide if a class may be `final` or `abstract` : probably not. This report is a great base to review the current class configuration, and ponder about the adding of such options. It is also interesting to review the list, and find classes that ought to be listed, but didn't make it : maybe those `abstractClass` that were supposed to be extended did find some other usage. In any case, time for a code review! # The Weekly Audits : 2018, Week #46 Exakat includes a 'weekly' report : this report is built with a selection of five analyses. This means a short audit report, with few issues to review. This is not a lot to read them, and review them in your code. Everyone in the PHP community can focus on one of the classic coding problems and fix it. Talk about the weekly audit around you : you'll find programmers facing the same challenges. To obtain the 'weekly' audit, run an audit, and request the 'Weekly' report. ``` # Init the project (skip when it is already done) php exakat.phar init -p -R https://github.com/Seldaek/monolog.git -git # Run the project (skip when it is already done) php exakat.phar project -p # Export the weekly project (every monday) php exakat.phar report -p -format Weekly # Open projects//weekly/index.html in your browser ``` Every week, you can find here 5 new analysis to review in your code. In fact, when your code is clean, you can also take a quick look at the upcoming Weekly recommendations for PHP code review : 2018, week 2018-46 - [Undefined static:: Or self::](https://exakat.readthedocs.io/en/latest/Rules.html#undefined-static-or-self) : List of all undefined static and self properties and methods. - [Useless Referenced Argument](https://exakat.readthedocs.io/en/latest/Rules.html#useless-referenced-argument) : The argument has a reference, but is only used for reading. - [preg_replace With Option e](https://exakat.readthedocs.io/en/latest/Rules.html#preg-replace-with-option-e) : preg_replace() supported the /e option until PHP 7. - [Must Call Parent Constructor](https://exakat.readthedocs.io/en/latest/Rules.html#must-call-parent-constructor) : Some PHP native classes require a call to parent::__construct() to be stable. - [Used Once Property](https://exakat.readthedocs.io/en/latest/Rules.html#used-once-property) : Property used once in their defining class. Every week, you can find here 5 new analysis to review in your code. In fact, when your code is clean, you can also take a quick look at the upcoming week with the 'Go further' section. # Happy PHP Code Reviews All the 362 analyzers are presented in the docs, including the faithful [Switch Without Default](http://exakat.readthedocs.io/en/latest/Rules.html#switch-without-default) : Always use a default statement in switch().. It is a routine bug : 56% applications mishandle switch(). You can check all of the Exakat reports at the gallery: [exakat gallery](https://www.exakat.io/exakat-gallery). Download Exakat on exakat.io, install it with [Docker](https://hub.docker.com/r/exakat/exakat/), upgrade it with 'exakat.phar upgrade -u' and like us on [github](https://github.com/exakat/exakat).