How to reduce duplication in your GitHub Actions workflows

Recently ReactJS v18 was released. I started to look into its improvements, and checked which of my projects could benefit from them.The main react-based project I maintain at the moment of writing this article is <a target="_blank" rel="noopener noreferrer" href="https://github.com/shlinkio/shlink-web-client">shlink-web-client</a>, so I naturally created a new branch and started the process.The update was quite smooth, as most of the other dependencies I was using from the react ecosystem were already updated to support v18. All but one, <a target="_blank" rel="noopener noreferrer" href="https://enzymejs.github.io/enzyme/">enzyme</a>, the testing framework I was using to unit-test react components.To be precise, I was able to continue running my tests, but some of them (those using <code>mount</code> instead of <code>shallow</code>) were still rendering components with the &quot;old&quot; React v17 approach, causing them to behave as in that version and a warning being printed in the console.<h3>First fix attempt</h3>The way enzyme integrates with the react version you are using is through an adapter library. The last official one supports only React v16, but someone released an <a target="_blank" rel="noopener noreferrer" href="https://github.com/wojtekmaj/enzyme-adapter-react-17">unofficial adapter for v17</a> which, with close to 650k weekly downloads, quickly became the way to go.I checked if there was one for React 18, but sadly there wasn&#x27;t.Also, the author of the adapter for v17 posted an article indicating <a target="_blank" rel="noopener noreferrer" href="https://dev.to/wojtekmaj/enzyme-is-dead-now-what-ekl">enzyme is dead</a>, he was not going to release one for v18, and publishing one for v17 was a mistake.With those facts in mind, I started to face what was probably going to be the moment to migrate to <a target="_blank" rel="noopener noreferrer" href="https://testing-library.com/docs/react-testing-library/intro">react testing library</a>.<h3>Migration strategy</h3>I decided to follow a migration strategy similar to the one suggested in the article above, but with a couple of modifications:<ul><li>I update to React 18 anyway, as tests still pass.</li><li>Migrate right away all tests using <code>mount</code>, as those are the ones behaving differently.</li><li>New tests should be written directly with react testing library (RTL from now on).</li><li>When an existing test needs to be changed, consider migrating it to RTL, and do it if there&#x27;s time.</li><li>Introduce some PR from time to time just migrating a handful of tests.</li><li>Once everything is migrated, get rid of everything related with enzyme.</li></ul><h3>First contact and impressions</h3>I was a bit sceptical with RTL, as it was focused more on integration tests, instead of unit tests, which meant I had to completely change the mindset to write tests.It also didn&#x27;t support shallow rendering, meaning that you will end up sometimes rendering a bigger component tree when testing container-like components, potentially causing side effects that could affect your test.On the other hand there&#x27;s more and more people stating that <a target="_blank" rel="noopener noreferrer" href="https://kentcdodds.com/blog/why-i-never-use-shallow-rendering">shallow rendering is an anti-pattern</a>, and that&#x27;s probably the reason of enzyme getting &quot;discontinued&quot;.Also, RTL has become the <a target="_blank" rel="noopener noreferrer" href="https://reactjs.org/docs/testing.html#tools">officially recommended framework</a> to test react components, it has become very popular, and it has even joined a wider group of testing libraries under the <a target="_blank" rel="noopener noreferrer" href="https://testing-library.com/"><code>@testing-library</code></a> organization.The thing is that I started to use it, and I was quickly surprised with how it felt to work with it, and all the benefits it was bringing to my tests.<h3>Benefits I have experienced</h3>Once I started migrating the first tests I noticed some benefits:<ul><li>Changing my mindset was actually easier than I thought. The docs are very well written, so it&#x27;s relatively easy to start using RTL.</li><li>My tests got simpler, and required less of those nasty global mocks that jest allows (I&#x27;m looking at you, <a target="_blank" rel="noopener noreferrer" href="https://jestjs.io/es-ES/docs/mock-functions#mocking-modules"><code>jest.mock</code></a>).</li><li>Tests were way less coupled with implementation details. I moved from testing the component props, to test what the user would see on the screen.</li><li>Related with previous point, I started to write my tests by looking at the screen instead of the component&#x27;s implementation.</li><li>Changes in source code led to fewer tests requiring to be changed.</li><li>A progressive migration was possible, where some tests still use enzyme and others are already using RTL.</li></ul>And overall, it felt good and I have already dedicated a couple of PRs just to migrate more tests.<h3>Challenges I faced</h3>But of course, migrating to a new tool always comes with its own challenges, and this was not an exception. I&#x27;ll explain the main ones I have faced so far and how I tackled them:<ul><li>RTL lets you do some things in a couple of different ways, and the docs may not be super clear about what&#x27;s the recommended option.For this I recommend reading <a target="_blank" rel="noopener noreferrer" href="https://acel.me/DCMb1">this article</a> from Kent C. Dodds, RTL&#x27;s author, which explains some common mistakes when using the library.</li><li>At first, I struggled a bit with asynchronous side effects and state changes in components, which can easily end up printing a warning like <code>Warning: An update to MyComponent inside a test was not wrapped in act</code>.The warning also explains how you are supposed to solve this by wrapping your code in <code>act()</code>, but this warning comes from React, not RTL, and what it is not telling you is that RTL already wraps all needed operations in <code>act()</code>.What this error usually mean is that you are not waiting for something to happen. <a target="_blank" rel="noopener noreferrer" href="https://acel.me/jnUdT">This other article</a>, also from Kent C. Dodds, explains everything you need to know about the things that can lead to this warning, and how to solve them.</li><li>Since you start testing from the user point of view, some use cases can be challenging to test without coupling with implementation details. For example, when you have a component which dynamically renders different images or icons, I used to directly check the component properties.For this I found the best solution was to use <a target="_blank" rel="noopener noreferrer" href="https://jestjs.io/docs/snapshot-testing">jest snapshots</a>. I didn&#x27;t want to manually check which SVG was being rendered in the DOM, just that different ones were being used in every case.<pre><pre><code class="language-tsx">// I went from this...
test(&#x27;...&#x27;, () =&gt; {
 const wrapper = shallow(&lt;MyComp dynamicValue=&quot;foo&quot; /&gt;);
 expect(wrapper.find(FontAwesomeIcon).prop(&#x27;icon&#x27;)).toEqual(someIcon);
})

// To this
test(&#x27;...&#x27;, () =&gt; {
 const { container } = render(&lt;MyComp dynamicValue=&quot;foo&quot; /&gt;);
 expect(container.firstChild).toMatchSnapshot();
})
</code></pre></pre></li><li>Something very similar happens if you use some library that renders canvas. There&#x27;s no way to test that from a DOM point of view, which is what RTL does.In my case I was using <a target="_blank" rel="noopener noreferrer" href="https://www.chartjs.org/">Chart.js</a> to render some charts, so I used <a target="_blank" rel="noopener noreferrer" href="https://github.com/hustcc/jest-canvas-mock">jest-canvas-mock</a>, which exposes a method on the canvas to see which are all the events invoked from the library.Then I used snapshots again to verify they had the expected &quot;shape&quot;.<pre><pre><code class="language-tsx">// I went from this...
test(&#x27;...&#x27;, () =&gt; {
 const wrapper = shallow(&lt;MyCompWithCanvas /&gt;);
 expect(wrapper.find(Chart).prop(&#x27;data&#x27;).datasets).toEqual(...);
})

// To this
test(&#x27;...&#x27;, () =&gt; {
 const { container } = render(&lt;MyCompWithCanvas /&gt;);
 const events = container.querySelector(&#x27;canvas&#x27;)?.getContext(&#x27;2d&#x27;)?.__getEvents();

 expect(events).toBeTruthy();
 expect(events).toMatchSnapshot();
})
</code></pre></pre></li></ul><h3>Conclusion</h3>For better or worst, enzyme should no longer be considered an option. If you are starting a new project or are using it on small ones, consider migrating to RTL as soon as possible.If you are using it in bigger projects, following the process described in this article will probably help you.In any case, you will get surprised. React testing library is a great tool and provides many benefits over enzyme.Its main issue is that it&#x27;s not a drop-in replacement for enzyme, so you will have to change a bit your mindset.

My experience migrating from enzyme to react testing library

Capturing code coverage for a test suite is a very useful way to know which parts of your source code are actually getting executed by tests.This is useful not only to know if you need to add more tests to your project (in case the coverage is too low), but also, if you want to apply technics like mutation testing, having a properly generated code coverage report will dramatically speed up te execution and help you know if a non-killed mutant is relevant.<h3>Generating the code coverage</h3>Capturing code coverage is usually easy in the most common types of tests, like unit tests, where the source code is executed in the same process.Tools like <a target="_blank" rel="noopener noreferrer" href="https://phpunit.de/">PHPUnit</a>, one of the most extended PHP testing frameworks, ships with tools like <a target="_blank" rel="noopener noreferrer" href="https://github.com/sebastianbergmann/php-code-coverage">php-code-coverage</a>, designed to capture the code under execution, just by providing a couple of lines of configuration.However, generating a reliable code coverage report is not always that easy for other types of tests.In contexts like E2E tests, where you may spin-up an API on a different process, and make your tests just call this API via HTTP and assert on the responses, PHPUnit will not be able to capture the code coverage, because the source code is actually being loaded on a different process.<h3>Remote code coverage</h3>A couple of weeks ago, I faced the issue described above. I had a web service for which I had a decent API test suite, but I wanted to capture code coverage for two main reasons:<ul><li>Be able to merge this coverage with the one generated by other tests suites, to know what&#x27;s the &quot;total&quot; code coverage, regardless the test producing it.</li><li>Apply mutation testing to the API tests, as I was already doing that for the rest of the test suites in the project. For this, I also needed to know exactly what tests were covering every line of the source code.</li></ul>After some investigation, I couldn&#x27;t find a built-in feature, where PHPUnit itself was able to &quot;remotely&quot; capture te code under test, so I had to think on a way to manually use <code>php-code-coverage</code> by myself.<h3>Code coverage reports</h3>In order to be able to capture code coverage, I had to make sure the instances of the objects provided by <code>php-code-coverage</code> where &quot;spin-up&quot; with the server, and then, the code coverage report was dumped at the end.Also, you usually define the code to include/exclude from coverage in PHPUnit&#x27;s config, but since this time we are the ones creating the coverage objects, this was not possible.I tried a couple of different approaches (more on this at the end), but the most accurate one for me, was to define two routes in my server, that were dynamically configured only when running the server in the context of these tests, and were responsible for creating and dumping the code coverage.<pre><pre><code class="language-php">use PHPUnit\Runner\Version;
use SebastianBergmann\CodeCoverage\CodeCoverage;
use SebastianBergmann\CodeCoverage\Driver\Selector;
use SebastianBergmann\CodeCoverage\Filter;
use SebastianBergmann\CodeCoverage\Report\Html\Facade as Html;
use SebastianBergmann\CodeCoverage\Report\PHP;
use SebastianBergmann\CodeCoverage\Report\Xml\Facade as Xml;

// Define directories containing the code you want to cover
$filter = new Filter();
$filter-&gt;includeDirectory(...);
$filter-&gt;includeDirectory(...);
$coverage = new CodeCoverage((new Selector())-&gt;forLineCoverage($filter), $filter);

// This is &quot;pseudo-code&quot;. Defining the routes depends on the framework you use
$app-&gt;get(&#x27;/api-tests/start-coverage&#x27;, function () use (&amp;$coverage) {
 $coverage-&gt;start(&#x27;API tests&#x27;);
 return new EmptyResponse();
});
$app-&gt;get(&#x27;/api-tests/stop-coverage&#x27;, function () use (&amp;$coverage) {
 $basePath = &#x27;...&#x27;; // Wherever you want the reports to be dumped
 $coverage-&gt;stop();

 // I generated coverage reports in a couple of different formats
 (new PHP())-&gt;process($coverage, $basePath . &#x27;/coverage.cov&#x27;);
 (new Xml(Version::getVersionString()))-&gt;process($coverage, $basePath . &#x27;/coverage-xml&#x27;);
 (new Html())-&gt;process($coverage, $basePath . &#x27;/coverage-html&#x27;);

 return new EmptyResponse();
});
</code></pre></pre>Then, I added the next snippet to my PHPUnit <code>bootstrap.php</code> file, to make sure the endpoints configured above are invoked at the proper times:<pre><pre><code class="language-php">// when starting up the test suite, call the endpoint to start collecting coverage
$httpClient-&gt;request(&#x27;GET&#x27;, &#x27;http://localhost:8080/api-tests/start-coverage&#x27;);

// When the tests process shuts down, call the endpoint to stop the coverage
register_shutdown_function(function () use ($httpClient): void {
 $httpClient-&gt;request(&#x27;GET&#x27;, &#x27;http://localhost:8080/api-tests/stop-coverage&#x27;);
});
</code></pre></pre><blockquote>Learn more about how to configure PHPUnit&#x27;s <a target="_blank" rel="noopener noreferrer" href="https://phpunit.readthedocs.io/en/9.5/configuration.html#the-bootstrap-attribute">bootstrap script</a>.</blockquote>This was fine from a pure code coverage point of view, but if you try it yourself, you will notice the report says all the code has been covered by <code>API tests</code>, which is what we provide when calling <code>$coverage-&gt;start(&#x27;API tests&#x27;);</code><img src="/assets/img/remote-coverage/invalid-api-coverage.png" alt="Invalid API coverage"/>To properly do mutation testing we need to know which are the exact tests that cover every part of the code. That requirement took me to the next approach.<h3>Supporting mutation testing</h3>To be more precise with the generated reports, I needed some way to notify the server about the specific test performing the request.One way to do this is by sending a custom header when performing a request from your tests, and registering some event handler or middleware which starts the coverage for that request with the value coming from that header.With that, I evolved the configuration above, and added a middleware handler (the framework I use is <a target="_blank" rel="noopener noreferrer" href="https://www.php-fig.org/psr/psr-15/">PSR-15</a> based, but the framework of your choice will probably have a way to do this).<pre><pre><code class="language-php">use ...

$coverage = new CodeCoverage();

// This ensures the coverage is started and stopped on every request, using the &quot;x-coverage-id&quot; header as the ID.
$app-&gt;middleware(function (ServerRequestInterface $req, RequestHandlerInterface $handler) use (&amp;$coverage) {
$coverage?-&gt;start(&#x27;API Tests&#x27;);
 $coverage-&gt;start($req-&gt;getHeaderLine(&#x27;x-coverage-id&#x27;));

 try {
 return $handler-&gt;handle($req);
 } finally {
 $coverage-&gt;stop();
 }
});

// This route is no longer needed. You can also remove the request from your bootstrap script
// $app-&gt;get(&#x27;/api-tests/start-coverage&#x27;, ...);
$app-&gt;get(&#x27;/api-tests/stop-coverage&#x27;, ...);
</code></pre></pre>Then, inside your test you can do something like this:<pre><pre><code class="language-php">use PHPUnit\Framework\TestCase;

class MyApiTest extends TestCase
{
 private ClientInterface $httpClient;

 public function setUp(): void
 {
 $this-&gt;httpClient = ...;
 }

 public function testMyEndpoint(): void
 {
 $resp = $this-&gt;httpClient-&gt;request(&#x27;POST&#x27;, &#x27;...&#x27;, [
 &#x27;headers&#x27; =&gt; [
 &#x27;x-coverage-id&#x27; =&gt; static::class,
 ],
 ])

 // Asserts go here...
 }
}
</code></pre></pre>After this, the code coverage reports will properly show the actual tests covering them.<img src="/assets/img/remote-coverage/valid-api-coverage.png" alt="Valid API coverage"/><h3>Alternative approach</h3>The approach explained here is functional, but it&#x27;s a bit hacky. I had to do it like this because of limitations with how I serve the API with <a target="_blank" rel="noopener noreferrer" href="https://openswoole.com">openswoole</a>.However, instead of defining routes that need to be actively called to start/stop the code coverage (or just to dump the report, as in the second approach), you could try to register the shutdown function directly in the server side.If that works for you, it&#x27;s much more straightforward, and you won&#x27;t need to bother changing your tests bootstrap script.<h3>Conclusion</h3>Even though there&#x27;s room for improvement, this allows to generate code coverage reports for code that&#x27;s running on a different process.I plan to apply something similar for E2E tests for a command line app, so maybe I extend this article at some point.Also, I decided to write this article, because at the moment of having to implement this myself, I didn&#x27;t find too much useful information out there.I hope this helped you, and now you can collect code coverage reports on your API tests.

Capturing remote code coverage in API tests with PHPUnit

In the last couple of days I have been playing around with the idea of combining GitHub Actions and GitHub Pages to be able to dynamically build preview environments every time a pull request is opened against a repository hosting a client-side web app.The idea is that you can quickly preview the changes made by some contributor, without having to clone their branch and running everything locally, something specially useful for open source projects.In this article I will explain how to set everything up, and what are some considerations and problems you may face during the process.<h3>Enable github pages</h3>The first thing you need to do is enable your project to publish pages on some branch. I recommend creating a new branch for this, let&#x27;s say <code>preview-env</code>, and then enabling publishing on it.In order to do that go to your repository and then Settings -&gt; Pages, look for the Source section, and you should see something like this:<img src="/assets/img/preview-envs/github-pages-before-enabling.png" alt="GitHub pages before enabling"/>Click in the dropdown and select your new branch, <code>preview-env</code>. Then click Save.<img src="/assets/img/preview-envs/github-pages-after-enabling.png" alt="GitHub pages after enabling"/>After saving you will see a message at the top of this section telling you what&#x27;s the URL in which the pages are published. It always follows the same pattern. If your organization is <code>my-org</code> and your repository is <code>my-repo</code>, the url will be <code>https://my-org.github.io/my-repo/</code>.<h3>Configure the workflow</h3>Now we need to configure a workflow that will &quot;deploy&quot; the preview environment for the branch every time a new pull request is created or updated:Let&#x27;s imagine we have a React web app that is built with node.js. The configuration could look like this.<pre><pre><code class="language-yml"># .github/workflows/deploy-preview.yml
name: Deploy preview

on:
 pull_request: null

jobs:
 deploy:
 runs-on: ubuntu-20.04
 continue-on-error: true
 steps:
 - name: Checkout code
 uses: actions/checkout@v2
 - name: Use node.js 14.15
 uses: actions/setup-node@v1
 with:
 node-version: 14.15
 - name: Generate slug
 id: generate_slug
 run: echo &quot;##[set-output name=slug;]$(echo ${GITHUB_HEAD_REF#refs/heads/} | sed -r &#x27;s/[~\^]+//g&#x27; | sed -r &#x27;s/[^a-zA-Z0-9]+/-/g&#x27; | sed -r &#x27;s/^-+\|-+$//g&#x27; | tr A-Z a-z)&quot;
 - name: Build
 run: npm ci &amp;&amp; npm run build
 - name: Deploy
 uses: JamesIves/github-pages-deploy-action@4.1.1
 with:
 branch: preview-env
 folder: build
 target-folder: ${{ steps.generate_slug.outputs.slug }}
 - name: Publish env
 uses: marocchino/sticky-pull-request-comment@v2
 with:
 header: Preview environment
 message: |
 ## Preview environment
 https://my-org.github.io/my-repo/${{ steps.generate_slug.outputs.slug }}/
</code></pre></pre><blockquote>If you are not familiar with GitHub Actions yet, take a look at the <a target="_blank" rel="noopener noreferrer" href="https://docs.github.com/en/actions">official documentation</a>.</blockquote>This workflow will follow the next steps:<ul><li>Checkout the code from the repository.</li><li>Set-up node.js 14.15</li><li>Based on the branch name, generate a slug that we will use to have separated deployment folders for every pull request we receive. The slug is exposed to next steps as an output.</li><li>Build the project. This step will obviously depend on the needs of your project.</li><li>Using <a target="_blank" rel="noopener noreferrer" href="https://github.com/JamesIves/github-pages-deploy-action">JamesIves/github-pages-deploy-action</a>, deploy the contents we previously built in the GitHub page, under a sub-folder matching the slug we generated a few steps above, and under the branch <code>preview-env</code> (remember we enabled GitHub pages for this branch).</li><li>Finally, using <a target="_blank" rel="noopener noreferrer" href="https://github.com/marocchino/sticky-pull-request-comment">marocchino/sticky-pull-request-comment</a>, post a comment in the pull request with a link to the preview environment, so that you can just click on it and see the deployment.</li></ul>The steps may change depending on your needs and how you build your project. For example, I have an extra step to update a property in the <code>package.json</code> that is then used to allow serving the app in a sub-path instead of the root of the domain.You may also not build your site with node.js, as you could be using any of the multiple existing static site generators out there, but you get the idea.Finally, you have probably noticed the config includes <code>continue-on-error: true</code>. This will allow the pull request to be merged even if this process fails for some reason.<h3>Considerations when using forks</h3>While the configuration above will work perfectly when creating pull requests inside the same repository, there are some limitations when the pull request comes from a fork (which is the usual in OSS projects).For security reasons, the <code>GITHUB_TOKEN</code> injected in those cases doesn&#x27;t have write permissions, which will make the &quot;deploy&quot; step fail.Also, you cannot define your own token with more permissions and inject it as a secret, as the secrets are not exposed to workflows running on forks.However, with a couple small config changes, we can work around these limitations:<h4>Change event</h4>The first thing we need to do is use the <code>pull_request_target</code> event instead of the <code>pull_request</code> one.<pre><pre><code class="language-diff">on:
- pull_request: null
+ pull_request_target: null
</code></pre></pre>According to the documentation, this is equivalent to the <code>pull_request</code> event, but it runs in the scope of the base repository.Thanks to this, the <code>GITHUB_TOKEN</code> will come with write permissions, and we will have access to secrets if needed.<h4>Checkout the fork</h4>The second thing we are going to change is that we now need to specify the repository to checkout.In order to do that, we need to add two inputs to the &quot;Checkout code&quot; step, like this:<pre><pre><code class="language-diff"> steps:
 - name: Checkout code
 uses: actions/checkout@v2
+ with:
+ repository: ${{ github.event.pull_request.head.repo.full_name }}
+ ref: ${{ github.event.pull_request.head.ref }}
</code></pre></pre>This will ensure we checkout from the fork repository, instead of the base one, which is the default, as it&#x27;s the one where the <code>pull_request_target</code> event is scoped to.And that&#x27;s it. With these two changes you can now deploy preview environments for pull requests coming from forks.<blockquote>IMPORTANT! The limitations of the <code>pull_request</code> event are there for a reason. People could potentially get access to your secrets or manipulate your code. Proceed at your own risk.</blockquote><h3>Other considerations</h3>Other than the limitations for forks, there are a few other minor things to take into consideration.<ul><li>Changes in GitHub Pages do not reflect immediately. It may take up to a couple of minutes for the deployment to be available, but considering you will usually not review a PR right after it has been created, this should not be a big issue.</li><li>As you have seen, every time a pull request is created, the deployment will generate a new folder in your GitHub Pages branch. This may result in a lot of old folders to pile-up, so you may want to set up some way to clean them up periodically or after the pull request has been merged.</li><li>Due to the fact that GitHub Pages only allows static pages to be served, this process cannot be used with apps that require some kind of back-end or server-side logic.</li><li>If your project is already using GitHub Pages for something else (serve the project&#x27;s website or docs), that may conflict with this, preventing you from having this kind of preview envs.</li></ul>

Setting-up a preview environment for your client-side apps with GitHub Actions and GitHub Pages

I remember many years ago, when I released my first open source project, that every time I had a new release ready, I was never sure what should be the new version number.Versioning software is not as straightforward as it might look when you don&#x27;t have a lot of experience.In this article I&#x27;ll try to explain the <a target="_blank" rel="noopener noreferrer" href="https://semver.org/">SemVer</a> approach to version software, and some things you might want to take into account on top of that.<h3>Semantic Versioning</h3>The first thing you need is a solid set of rules that help you decide which should your next version be.I remember thinking &quot;is this version big enough as to jump from 1.0 to 2.0?&quot; or &quot;I have seen projects using three numbers for the version, X.Y.Z, should I do the same?&quot;Those questions are easier to answer if you stick to some standard that tells you what to do, and that will help others more easily understand your intention.My recommendation is to use <a target="_blank" rel="noopener noreferrer" href="https://semver.org/">Semantic Versioning</a>, as it defines a solid starting point, and it&#x27;s quite adopted by the community.Semantic Versioning states that you should use three numbers to identify versions, <code>MAJOR.MINOR.PATCH</code>, and follow these rules in order to decide which one to increase:<ul><li><code>PATCH</code>: the new release includes only bug fixes. People are encouraged to update to this release and no changes are needed in their code bases.</li><li><code>MINOR</code>: the new release includes new backwards-compatible features. People can update to this version without changing their code bases, and make use of the new features afterwards if they wish.</li><li><code>MAJOR</code>: the new release includes <a target="_blank" rel="noopener noreferrer" href="https://en.wikipedia.org/wiki/Backward_compatibility">backward compatibility</a> breaks. Changes in the code base will be needed when updating to this version.</li></ul><blockquote>These rules are easier to apply to libraries and frameworks than it is for apps and services. More about this later.</blockquote><h3>Try to keep backwards-compatibility</h3>Ok, we have some rules now. However, I have seen very frequently people mistaking what can be done with what should be done.Yes, if you introduce a breaking change, you can update the major version and that&#x27;s it. However, if you do it too frequently, people won&#x27;t be happy, and you will end up with a fragmented user base, that stop updating to newer versions.I remember using a library to deploy stuff that had a new major version every couple of months, changing things like &quot;The <code>host</code> function is now called <code>server</code>&quot;. Yes, ok, but why do I have to change my stuff so frequently.It&#x27;s usually better to try to implement things in a backwards-compatible way, and keep track of the things you want to change and do it all at a time.You can also deprecate things, and document the way you want those things to be done moving forward. That way you give people the chance to start changing their code and simplify a hypothetical upcoming major release.<h3>Provide clear upgrade paths</h3>As mentioned above, too frequent major version changes are not desirable, but sooner or later you will want to release a new major version for different reasons.<ul><li>Getting rid of that feature which is hard to maintain, introduces lots of bugs, and provides little value.</li><li>Supporting something new which is very hard to implement without breaking backwards compatibility.</li><li>Removing all those deprecated methods you have been dragging for months.</li><li>Fix design issues, where something was architected in the wrong way, and only spotted after some time.</li></ul>At the time this happens you will want your users to upgrade to the newer version, as you don&#x27;t want people to report bugs that only affect older versions, or to expect you to backport fixes to older versions because they haven&#x27;t updated to the new one.The best way to achieve this is to provide clear and simple upgrade paths:<ul><li>Prepare your releases for the things to come: If you want to introduce new ways of doing things, do it before the major release, and deprecate the older ones. For example, you can have a new method that gets called by an older one, while you mark the old one as deprecated.People will be more willing to update and change their code afterwards. By the time the major release is published, their code will be ready to upgrade.</li><li>Include a CHANGELOG file in your project, explaining the changes introduced in every version. A very good way to document a change log is the <a target="_blank" rel="noopener noreferrer" href="https://keepachangelog.com/">Keep a changelog</a> initiative.You can also use some other platform to document the change log, like GitHub releases.</li><li>Include documentation on how to upgrade to a major release: This is probably the most important one. Document all the steps that need to be followed and all the required changes to update from a release to the next major one.A good way to do this is by including an UPGRADE file in your project. You can see <a target="_blank" rel="noopener noreferrer" href="https://github.com/acmailer/acmailer/blob/main/UPGRADE.md">this example</a>.</li></ul><h3>Versioning libraries vs apps</h3>Semantic Versioning is a good standard to version software, but it plays much better with libraries and frameworks that are installed using some kind of package manager, than it does with apps and services that are not directly depended on.For example, how do you identify a backward compatibility break on a web user interface?With this kind of software there are more grey areas, and you will end up using your intuition.For example, not long ago I released a <a href="/2020/12/24/released-shlink-web-client-v3-0-0/">new major version</a> for a web app I maintain, and it was completely compatible with the previous one. However, it introduced a larger amount of features than usual, and big UI changes, so I decided it was worth the bump.Because of this there are projects that use different approaches to version apps. For example:<ul><li>Firefox and Chrome have 6-week cycles, and after each one of them they release a new major version no matter what.</li><li>Jetbrains publishes a few releases of their IDEs every year (I think 3) which always start with the year they were released on, like <code>2020.3.0</code>, and they increase the patch number for bugfixes.</li><li>Ubuntu releases 2 versions every year, one in April and one in October, and they are always identified by the year and month they were released on, like <code>19.04</code> or <code>20.10</code>.</li></ul><h3>Special versions</h3>There&#x27;s also a set of special versions that can be used to publish the so-called pre-release versions. These <a target="_blank" rel="noopener noreferrer" href="https://semver.org/#spec-item-9">are covered</a> by Semantic Versioning, but sometimes they are not so easy to understand.It is also very likely that you never have to use these, as only relatively big projects will need this level of granularity, but it&#x27;s still good to know what&#x27;s their purpose and what do they imply.<h4>0.x.y</h4>It is possible to release a version of your software where the major number is <code>0</code>. When this happens, it means your software is still in its early stages.It does not mean it&#x27;s necessarily unstable, but it means you are still introducing frequent changes on it, and therefore, it might be a bit more fragile than a version starting with a number greater than <code>0</code>.<h4>Alpha</h4>The intention of an alpha release is that a subset of people con test some new functionality, but you don&#x27;t want people to use it in productionAlpha versions are on their very early stages. Their public API is very likely to change, and they probably contain bugs.Semantic Versioning states that alpha versions are identified by this pattern: <code>MAJOR.MINOR.PATCH-alpha.NUMBER</code>, for example <code>2.0.0-alpha.1</code>.<h4>Beta</h4>Similar to alpha versions, beta versions are also prone to contain bugs, but their API will in theory not change. That means that you could potentially adapt your software to start using a beta version, and when the corresponding stable release is published, you shouldn&#x27;t need that many changes.Semantic Versioning defines a pattern similar to the one for alpha versions: <code>MAJOR.MINOR.PATCH-beta.NUMBER</code>, for example <code>2.0.0-beta.1</code>.<h4>Release candidate</h4>Release candidates (RC) are pre-release versions that you will want to publish for the general user-base to test an upcoming release. You want to publish a RC so that it&#x27;s battle tested by as many people as possible, in order to find possible bugs and edge cases.They should not contain many bugs, but some could be found. The public API should not change anymore.According to Semantic Versioning, the pattern to identify a RC is <code>MAJOR.MINOR.PATCH-rc.NUMBER</code>, for example <code>2.0.0-rc.1</code>.<h3>Conclusion</h3>We have seen some approaches and considerations to properly version your software.Versioning is not so straightforward when you don&#x27;t have a lot of experience, but as you have seen, you just need to know a small set of rules and use a bit your intuition.With those tools, you will be able to properly version your software.

What to take into account when versioning software

The day Zend Expressive 2 was released I was super excited. I have been using it a lot for both professional and personal projects, so I&#x27;m quite used to it.Since I&#x27;ve been using it in many projects, being able to update all of them to version 2 was a challenge, but I can say, I have succeed :-)<h3>The projects</h3>I have used expressive for two small websites, <a target="_blank" rel="noopener noreferrer" href="https://www.alejandrocelaya.com">https://www.alejandrocelaya.com</a> and <a target="_blank" rel="noopener noreferrer" href="https://shlink.io">https://shlink.io</a>.The code can be found <a target="_blank" rel="noopener noreferrer" href="https://github.com/acelaya/alejandrocelaya.com">here</a> and <a target="_blank" rel="noopener noreferrer" href="https://github.com/shlinkio/shlink.io">here</a>.When I migrated my website to expressive, I had to create a custom router for backward compatibility reasons, because none of the provided implementations supports optional params at the beginning of the path, and I was using them.That&#x27;s why I created <a target="_blank" rel="noopener noreferrer" href="https://github.com/acelaya/expressive-slim-router">this</a> implementation based on Slim framework router (Slim 2, not 3). Since expressive 2 depends on the expressive router 2, I had to release a new version of this component too.The next project to migrate was <a target="_blank" rel="noopener noreferrer" href="https://github.com/shlinkio/shlink">Shlink</a>, a little OSS project of my own. Like its website, it is based on expressive too.This is a little bit bigger application, but not too big anyway.Shlink is mainly a REST API, but has two or three endpoints that are meant to be consumed by humans in a web browser. For this reason I created a component that was responsible of handling errors in a different way, depending on the request&#x27;s <code>Accept</code> header.Since the concept of error handling has completely changed in expressive 2, that library needed to be updated too: <a target="_blank" rel="noopener noreferrer" href="https://github.com/acelaya/ze-content-based-error-handler">https://github.com/acelaya/ze-content-based-error-handler</a>And I left the two most important projects for the end.First, my company&#x27;s website. Another small project, not too hard to migrate.Finally, my company&#x27;s main product. A big and modular REST API, with about 100 actions/middlewares I wanted to migrate to <a target="_blank" rel="noopener noreferrer" href="https://github.com/http-interop/http-middleware">http-interop middleware</a>. It wasn&#x27;t difficult, but it took me a while to fix all tests xD.In the end I migrated 5 projects and 2 libraries, and I am quite proud of the result.<h3>The process</h3>When I decided to migrate the first project, I started by following this article from the official documentation: <a target="_blank" rel="noopener noreferrer" href="https://docs.zendframework.com/zend-expressive/reference/migration/to-v2/">https://docs.zendframework.com/zend-expressive/reference/migration/to-v2/</a>.It has a very detailed explanation with everything you need to know. Indeed, the best achievement of the Zend Framework team has been the number of articles, tools and documentation they provide to make this migration easier.They have also spent a lot of time on making as many features as possible, backward compatible, to the point that almost everything keeps working after updating the components.My conclusion after reading the article was that the only two things I needed to fix was the error handler and the middlewares signature, to use the single-pass approach instead of the old double-pass. However, the second one is not really necessary, since double-pass middleware keeps working with expressive 2, but I wanted to change it.<h3>Error handler</h3>At first, when one reads the docs, it seems that changing the error handler is going to be hard.They explain the idea behind the new approach, why they have changed it, and how you should implement it.The fact is that after reading this you realize expressive 2 and stratigility 2 come with a basic implementation that makes migrating from the old error handler to the new approach as easy as registering two services and one middleware. Done.Now, instead of having a component that gets called when the middleware stack gets exhausted or an exception is thrown, like in expressive 1, the recommendation is to register a middleware at the outermost layer of the stack, that is responsible of catching any exception thrown by any inner middleware. Basically, what you do is invoke the next middleware inside a try/catch, and return an error response if the catch block is reached.Stratigility 2 comes with a <code>Zend\Stratigility\Middleware\ErrorHandler</code> middleware that already does this. Just pipe it at the beginning of the stack and register the service using the provided <code>Zend\Expressive\Middleware\ErrorHandlerFactory</code> factory.In expressive 1, the error handler was responsible of returning a response object. Now, this new ErrorHandler middleware delegates this responsibility into a service called ErrorResponseGenerator. Stratigility comes with an implementation, the <code>Zend\Stratigility\Middleware\ErrorResponseGenerator</code> that returns plain text errors, like the old stratigility ErrorHandler used to do.On the other hand, expressive comes with two implementations, the <code>Zend\Expressive\Middleware\ErrorResponseGenerator</code>, which gets a template renderer injected, and acts like the old <code>TemplatedErrorHandler</code>, and also, a <code>Zend\Expressive\Middleware\WhoopsErrorResponseGenerator</code>, which is meant to be used in development, and acts like the old <code>WhoopsErrorHandler</code>.In other words, in order to migrate the error handler, you just need to do three things:<ul><li>Remove the old <code>Zend\Expressive\ErrorHandler</code> service</li><li>Register both <code>Zend\Stratigility\Middleware\ErrorHandler</code> and <code>Zend\Expressive\Middleware\ErrorResponseGenerator</code>, with whichever implementation you want.</li><li>Pipe the <code>Zend\Stratigility\Middleware\ErrorHandler</code> middleware as the outermost middleware of your stack.</li></ul>After doing this, everything should work.<h3>Error middleware</h3>Expressive 1 had a feature called error middleware.These middlewares were not exactly the same as regular middleware. Instead, they received a fourth <code>error</code> param, and were piped at the end of the stack, so they were invoked only if the latest regular middleware called the next one, or any other middleware called next with an <code>error</code> parameter, which had the effect of bypassing any other regular middleware and jumping directly to the first error middleware.I never liked this feature, because it wasn&#x27;t clear.<ul><li>What if I pipe error middleware between regular middleware, with a higher priority? Does it get invoked?</li><li>Why error middleware doesn&#x27;t get invoked in case of status 404 or 405? Isn&#x27;t that an error? Apparently not.</li><li>What is an &quot;error&quot; in the scope of middleware then? An exception only?</li></ul>Because I was never sure how to use error middleware, I decided to reduce it to the point that only one of the projects had one error middleware that was responsible of logging exceptions in a file.Gladly, the new error handling approach, the <code>Zend\Stratigility\Middleware\ErrorHandler</code>, allows &quot;error&quot; listeners to be attached, so that when an exception is caught, the error can be processed by any number of listeners.The signature of the listeners is the same as the error middlewares used to have. Invokable objects with three parameters, an error, a request and a response.This allowed me to register that error middleware as a listener, and just remove the return statement, which is no longer used.<h3>Single-pass middleware</h3>One of the most important new features in expressive 2, and the one I most wanted to use, is the support for interop middleware. It is what has been proposed to end up as the <a target="_blank" rel="noopener noreferrer" href="https://github.com/php-fig/fig-standards/blob/master/proposed/http-middleware/middleware.md">psr-15</a> standard for server middleware.The main difference with middleware in expressive 1 is that middlewares no longer get the response object (which is less error prone), and that the last argument is no longer a <code>callable</code>, but an object (the delegate) which invokes the next middleware and returns the response generated by it.Migrating middlewares to this approach is very easy. Remove the second argument and replace <code>$out($request, $response)</code> by <code>$delegate-&gt;process($request)</code>. Done.The hardest part here is migrating tests.Since expressive 1 middlewares are <code>callables</code>, I used to use <code>Closures</code> in tests. Now, the last argument is type hinted to <code>DelegateInterface</code>, so you have to explicitly mock it.I have used <a target="_blank" rel="noopener noreferrer" href="https://github.com/phpspec/prophecy">prophecy</a>, which comes with PHPUnit, and it works like a charm. It&#x27;s not very difficult, but it could take a while if the application is big.Of course, If you don&#x27;t test your code, you won&#x27;t have this problem, but I hope it is not your case ;-)Tests allowed me to be sure all middlewares and actions were still working, before testing the apps manually.<h3>Router</h3>Changes in the router shouldn&#x27;t affect you, unless you have implemented your own router, like me.However, the change is very small. This is what I had to change: <a target="_blank" rel="noopener noreferrer" href="https://github.com/acelaya/expressive-slim-router/commit/46bb000cb4389a6be6bff1335f875d7c6d8f5ca9">feature/v3</a>You could also be affected by this if you rely on the <code>RouteResult</code> in any of your middlewares and used to call <code>RouteResult::fromRouteMatch()</code> in tests. Just replace it by <code>RouteResult::fromRoute()</code> and that&#x27;s it.<h3>Programmatic approach</h3>Another of the changes in expressive 2 is that now they promote the programmatic approach to configure routes and pipe middlewares, because newcomers find it easier to understand.However, the config-driven approach still works, and you can still use it if you want.That&#x27;s my case indeed. I like having my modules provide different routes, instead of defining all of them in a single config file. It better fits my workflow and my way of thinking.Something similar happens with middleware, I prefer defining it in a config file with array notation. However, I have to confess I have moved all the middleware config to a single file in all projects. I have found that, as the project grows, since middleware needs to be piped in a specific order, defining it in different files makes it harder to maintain and much more error prone. This is probably one of the reasons of promoting the programmatic approach.<h3>Conclusion</h3>My conclusion after migrating all these projects is that expressive is a great framework, and the Zend Framework team is expending a lot of time to make it scalable, maintainable an usable.The more I use it, the more I see it is the best option for projects of any size. A framework where everything is perfectly explained, with a really good documentation, very loosely coupled with any other component, and a framework where you always have the last word.No black magic or obscure conventions. But at the same time, you can quickly prototype any application without writing a lot of boilerplate code.Thanks to all of this, the migration between major versions has been a breeze.

My thoughts after migrating some projects to Zend Expressive 2

It has been a long time since I first realized that handling file uploads in non-POST requests (like PUT) wasn&#x27;t an easy task.One could assume the <code>$_FILES</code> array should be populated regardless the HTTP verb, but actually, PHP doesn&#x27;t do it on its own.After a long time wanting to find a solution to this problem, I&#x27;ve finally dedicated the time to get something functional, that allows file uploads to be transparently handled regardless the HTTP verb (it works the same way in POST, PUT and PATCH requests).Since nowadays I try to work with psr-7/middleware based applications, I have created a <a target="_blank" rel="noopener noreferrer" href="https://docs.zendframework.com/zend-expressive/">Zend Expressive</a> app that registers a middleware capable of parsing a <code>multipart/form-data</code> request body, populating the request&#x27;s uploaded files array and parsed body array.This way, you can call <code>$request-&gt;getUploadedFiles()</code> or <code>$request-&gt;getParsedBody()</code> in any PUT or PATCH action, the same way you would do in a POST action.You can find the example application here: <a target="_blank" rel="noopener noreferrer" href="https://github.com/acelaya-blog/put-patch-file-uploads">https://github.com/acelaya-blog/put-patch-file-uploads</a><h3>The example</h3>When you clone the application, enter the project directory and run <code>composer install &amp;&amp; composer serve</code>. Then you should be able to access <a target="_blank" rel="noopener noreferrer" href="http://localhost:8080">http://localhost:8080</a> and see something like this:<img src="%7B%7Bsite.url%7D%7D/assets/img/put-patch-uploads/app-screenshot.png" alt="Example application"/>This is a simple form which submit event is captured via javascript in order to get it sent using the selected HTTP verb.The server then dumps the request&#x27;s uploaded files and parsed body using <a target="_blank" rel="noopener noreferrer" href="http://symfony.com/doc/current/components/var_dumper.html">symfony/var-dumper</a>, and the result is appended to the bottom of the page.Using the browser&#x27;s console you should be able to see the actual request. Regardless the selected HTTP method, the result should be exactly the same.Also, all the uploaded files will be stored in the <code>data/files</code> folder.This is done by the <a target="_blank" rel="noopener noreferrer" href="https://github.com/acelaya-blog/put-patch-file-uploads/blob/master/src/App/Action/UploadAction.php">UploadAction</a> class, which is dispatched when the /upload route is resolved with POST, PUT or PATCH methods.<h3>Let&#x27;s see how it works</h3>If we wouldn&#x27;t have done anything, this example would only work in POST requests. PUT and PATCH requests would always print an empty array of files and parsed body.The class responsible of doing the magic is the <a target="_blank" rel="noopener noreferrer" href="https://github.com/acelaya-blog/put-patch-file-uploads/blob/master/src/App/Middleware/MultipartRequestBodyParser.php">MultipartRequestBodyParser</a>. Let&#x27;s analyze it.The first couple of lines is simple. This middleware should only be executed when the request uses one of the HTTP verbs that allows body, but POST, which is automatically parsed by PHP. Also, the content type of the request should be <code>multipart/form-data</code><pre><pre><code class="language-php">&lt;?php
namespace App\Middleware;

use App\File\UploadedFile;
use Fig\Http\Message\RequestMethodInterface;
use Psr\Http\Message\ResponseInterface;
use Psr\Http\Message\ServerRequestInterface;

class MultipartRequestBodyParser implements RequestMethodInterface
{
 public function __invoke(ServerRequestInterface $request, ResponseInterface $response, callable $next = null)
 {
 // Find content type
 $contentTypeParts = explode(&#x27;; boundary=&#x27;, $request-&gt;getHeaderLine(&#x27;content-type&#x27;));
 if (count($contentTypeParts) === 1) {
 $contentTypeParts[] = &#x27;&#x27;;
 }

 // Apply this middleware only to PUT and PATCH requests when content type is multipart/form-data
 list($contentType, $boundary) = $contentTypeParts;
 if ($contentType !== &#x27;multipart/form-data&#x27;
 || ! in_array($request-&gt;getMethod(), [self::METHOD_PUT, self::METHOD_PATCH], true)
 ) {
 return $next($request, $response);
 }
 
 // [...]
 }
}
</code></pre></pre>First, we get the content type, and a boundary, that will be used later to identify every body part.If either the request method or content type are not correct, we just call the next middleware.But let&#x27;s see now what happens when those conditions are met:<pre><pre><code class="language-php">class MultipartRequestBodyParser implements RequestMethodInterface
{
 public function __invoke(ServerRequestInterface $request, ResponseInterface $response, callable $next = null)
 {
 // Find content type
 // [...]

 // Apply this middleware only to PUT and PATCH requests when content type is multipart/form-data
 // [...]
 
 // Explode parts
 $parts = explode(&#x27;--&#x27; . $boundary, (string) $request-&gt;getBody());
 // Discard first and last part, which are inconsistencies from previous explode
 $parts = array_slice($parts, 1, count($parts) - 2);

 $bodyParams = [];
 $files = [];
 foreach ($parts as $part) {
 $this-&gt;processPart($files, $bodyParams, $part);
 }

 return $next(
 $request-&gt;withUploadedFiles($files)
 -&gt;withParsedBody($bodyParams),
 $response
 );
 }
}
</code></pre></pre>Using the boundary (the identifier used in multipart requests to separate each part), we explode the body in order to get every separated part, and then iterate them in order to get them processed.The <code>processPart</code> protected method is responsible of finding out the type of the part, and appending it to the <code>$files</code> array or the <code>$bodyParams</code> array. Both of those arrays are passed by reference.Once both arrays have been populated, the next middleware is invoked, but the request now includes this information.Let&#x27;s see the <code>processPart</code> method implementation:<pre><pre><code class="language-php">class MultipartRequestBodyParser implements RequestMethodInterface
{
 public function __invoke(ServerRequestInterface $request, ResponseInterface $response, callable $next = null)
 {
 // [...]
 }
 
 protected function processPart(array &amp;$files, array &amp;$bodyParams, $part)
 {
 // Separate part headers from part body
 $part = ltrim($part, &quot;\r\n&quot;);
 list($partRawHeaders, $partBody) = explode(&quot;\r\n\r\n&quot;, $part, 2);

 // Cast headers into associative array
 $partRawHeaders = explode(&quot;\r\n&quot;, $partRawHeaders);
 $partHeaders = array_reduce($partRawHeaders, function (array $headers, $header) {
 list($name, $value) = explode(&#x27;:&#x27;, $header);
 $headers[strtolower($name)] = ltrim($value, &#x27; &#x27;);
 return $headers;
 }, []);

 // Ignore any part without content disposition
 if (! isset($partHeaders[&#x27;content-disposition&#x27;])) {
 return;
 }

 // Parse content disposition, in order to find out the nature of each field
 $contentDisposition = $partHeaders[&#x27;content-disposition&#x27;];
 preg_match(
 &#x27;/^(.+); *name=&quot;([^&quot;]+)&quot;(; *filename=&quot;([^&quot;]+)&quot;)?/&#x27;,
 $contentDisposition,
 $matches
 );
 $name = $matches[2];
 $filename = isset($matches[4]) ? $matches[4] : null;

 // Check if current part is a properly uploaded file, a not uploaded file or another field
 if ($filename !== null) {
 // If file was correctly uploaded, write into temp dir and create an UploadedFile instance
 $tempFile = tempnam(ini_get(&#x27;upload_tmp_dir&#x27;), &#x27;php&#x27;);
 file_put_contents($tempFile, $partBody);

 $this-&gt;addFile($files, $name, new UploadedFile(
 $tempFile,
 strlen($partBody),
 UPLOAD_ERR_OK,
 $filename,
 isset($partHeaders[&#x27;content-type&#x27;]) ? $partHeaders[&#x27;content-type&#x27;] : null
 ));
 } elseif (strpos($contentDisposition, &#x27;filename&#x27;) !== false) {
 $this-&gt;addFile($files, $name, new UploadedFile(
 null,
 0,
 UPLOAD_ERR_NO_FILE
 ));
 } else {
 $bodyParams[$name] = substr($partBody, 0, -2);
 }
 }
}
</code></pre></pre>This is the most complex method. Using a couple of explodes, an <code>array_reduce</code> and a regular expression, this method separates the headers from the body of every part, and then, depending on the information present in the content-disposition header of the part, it determines if it belongs to a properly uploaded file, a file element that has not been uploaded or a regular body parameter.When a properly uploaded file is found, it is written in the directory configured in the ini upload_tmp_dir option, using the same file pattern used by PHP when storing files uploaded to a POST request. Finally, it appends the parsed field to the <code>$bodyParams</code> array or the <code>$files</code> array.There&#x27;s only one thing left to see. When an uploaded file is found, the <code>addFile</code> protected method is called. Let&#x27;s see it:<pre><pre><code class="language-php">class MultipartRequestBodyParser implements RequestMethodInterface
{
 public function __invoke(ServerRequestInterface $request, ResponseInterface $response, callable $next = null)
 {
 // [...]
 }
 
 protected function processPart(array &amp;$files, array &amp;$bodyParams, $part)
 {
 // [...]
 }
 
 protected function addFile(array &amp;$files, $name, UploadedFile $newFile)
 {
 $isArray = false;

 // If name has array notation, append it as array
 if (strpos($name, &#x27;[]&#x27;) === strlen($name) - 2) {
 $name = substr($name, 0, -2);
 $isArray = true;
 }

 if (! isset($files[$name])) {
 $files[$name] = $isArray ? [$newFile] : $newFile;
 return;
 }

 $files[$name] = $isArray ? array_merge($files[$name], [$newFile]) : $newFile;
 }
}
</code></pre></pre>Since files can be uploaded as arrays, we have to take it into account when generating the <code>$files</code> array.If the name of the array uses the array notation (including brackets at the end, like <code>someFile[]</code> instead of <code>someFile</code>), we have to make sure the value of that file element is an array of <code>UploadedFileInterface</code> objects, and any part that is a file and uses that same name is appended to the same array under the same name.And that&#x27;s it. If you have made some tests with the example app, you have already seen how it works.<h3>Considerations</h3>Regardless this works, it is just an experiment, and I wouldn&#x27;t recommend you to do this in your project, unless it is essential for the application to be able to upload files in a PUT or PATCH request.If you can, I would rather change the endpoint, so that it works with the POST method.These are the main reasons:<ul><li>The <code>UploadedFile</code> object implementation included in <a target="_blank" rel="noopener noreferrer" href="https://docs.zendframework.com/zend-diactoros/">zend/diactoros</a> (and thus, in zend expressive), calls PHP&#x27;s <code>move_uploaded_file</code> when the <code>$file-&gt;moveTo()</code> method is called (probably, other implementations do the same). 
This throws an exception in PUT and PATCH requests, since PHP doesn&#x27;t consider those files to have been uploaded. 
In order to get this working, in this example I have included a new <a target="_blank" rel="noopener noreferrer" href="https://github.com/acelaya-blog/put-patch-file-uploads/blob/master/src/App/File/UploadedFile.php">UploadedFile</a> implementation, which extend&#x27;s from diactoros&#x27; implementation, but always moves the file using the resource, without checking if the file is really an uploaded file. 
While this solution works, it has some security concerns, and could be exploited by a malicious attacker.</li><li>This solution implies loading the whole body into memory, in order to parse files and temporarily save them in disk, which is a much less optimized process than having them already in disk, like in POST requests.</li><li>Generated temporary files are not deleted at the end of the request, like in POST requests. However, we could use <code>tmpfile</code> instead of <code>tempnam</code>, or delete the files after calling <code>$next</code>, if they already exist and have not been handled by other middlewares.</li></ul>Apart from that, I hope you learned reading the article as much as I did writing it.Now I can say I know better how multipart requests work.

Managing PUT requests with file uploads in psr-7 and middleware PHP applications

Docker is, without any doubt, the trending tool these days. Everybody wants to use it, because it is very useful, allowing to easily generate development environments for any kind of application.A couple months ago I started working with docker myself (it has taken me a while, I know), and now I can&#x27;t imagine working without it.I started using it at work, but now I&#x27;m migrating all of my OSS projects too.<h3>The first stopper</h3>Regardless docker is very cool, there is a problem when you start using it.I had my development environment perfectly configured, and all my tools properly integrated. I was able, among other things, to run any project tests from within PhpStorm, just by right-clicking any test class, test method or phpunit.xml file, and selecting the &quot;Run&quot; option.However, once you start using docker in the project, it is not that simple.<h3>Integration with PhpStorm</h3>Gladly, since PhpStorm is a very powerful tool, it supports integration with docker, which can be then used, among other things, to automatically run tests inside a container.<blockquote>From this point, I&#x27;m going to explain the process, assuming you have already installed docker in your system. If not, you need to install at least <a target="_blank" rel="noopener noreferrer" href="https://docs.docker.com/engine/installation/">docker engine</a> and <a target="_blank" rel="noopener noreferrer" href="https://docs.docker.com/compose/install/">docker compose</a>.</blockquote>The first thing you need to do is configure the connection with docker engine. Go to Settings -&gt; Build, Execution, Deployment -&gt; Docker.Click the green plus button and a new docker connection will be created. The only value you should need to change is the API URL:<ul><li>Linux: unix:///var/run/docker.sock</li><li>Windows and Mac: <a target="_blank" rel="noopener noreferrer" href="http://127.0.0.1:2376">http://127.0.0.1:2376</a> (The URL of the docker machine. If you are using the deprecated docker toolbox with boot2docker, you have to make sure which is the IP address of the virtual machine)</li></ul><img src="/assets/img/phpstorm-docker/phpstorm-docker.png" alt="Docker in PhpStorm"/>Apply changes and we are done here.<h3>Create the remote interpreter</h3>Now let&#x27;s create a remote interpreter. It will be used so that tools that need a php runtime are executed inside a docker container.Go to Settings -&gt; Languages &amp; Frameworks -&gt; PHP. In here, you select the default interpreter for your project.<img src="/assets/img/phpstorm-docker/interpreter.png" alt="Interpreter"/>Click the button with the three dots, which will open the dialog to create a new interpreter.<img src="/assets/img/phpstorm-docker/interpreter-dialog.png" alt="Interpreter dialog"/>In that dialog you will likely have a local interpreter. Click the green plus button, at the top-left corner, and select Remote.That will open the dialog to create a new remote interpreter. One of the options is to use a docker image from which PhpStorm will create a docker container that should contain a php interpreter.<img src="/assets/img/phpstorm-docker/docker-interpreter.png" alt="Docker iterpreter"/>In this dialog, just select the server (this is the connection with the docker engine, the one we created in the first step), then select the docker image you want to use. The dropdown will be filled with all the images in your machine.Finally select the interpreter path. Usually, <a target="_blank" rel="noopener noreferrer" href="https://hub.docker.com/_/php/">PHP-based docker images</a> have the php interpreter in the PATH, so just setting <code>php</code> should be enough.Save everything and we are done configuring the interpreter.<h3>Create the PHPUnit config</h3>Now that the interpreter is created, we have to define a phpunit configuration that uses it.Go to Settings -&gt; Languages &amp; Frameworks -&gt; PHP -&gt; PHPUnit, Use the green plus button at the top-left corner, select By Remote interpreter and a dialog window will be prompt.It only contains a dropdown where you have to select the remote interpreter we created in previous step.Select it and you&#x27;ll see a configuration similar to this.<img src="/assets/img/phpstorm-docker/phpunit.png" alt="PHPUnit configuration"/>As you can see, PhpStorm mounts the project dir as a volume inside the container, in the <code>/opt/project</code> dir, and based on that path, selects the path to composer&#x27;s autoloader script and the phpunit.xml script.If any of those params is not correct in your project, you can (and should) change it.And that&#x27;s it!Now, you can right-click any test class, test method or phpunit.xml file and select &quot;Run&quot;. PhpStorm will automatically connect with docker engine, set up a temporary container and run the tests inside of it.You&#x27;ll know it is working because of this:<img src="/assets/img/phpstorm-docker/tests-in-container.png" alt="Tests inside container"/><h3>Conclusion</h3>PhpStorm&#x27;s team is always working to add integrations with the latest development tools, making it the most powerful IDE for PHP.Now go, configure your environment and start using docker. It&#x27;s amazing!