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

Let&#x27;s not deny that <a target="_blank" rel="noopener noreferrer" href="https://github.com/features/actions">GitHub actions</a> are hitting hard in the tech community, and many projects are transitioning from other continuous integration systems like <a target="_blank" rel="noopener noreferrer" href="https://circleci.com/">Circle CI</a> or <a target="_blank" rel="noopener noreferrer" href="https://travis-ci.org/">Travis CI</a>.Personally I have been using Travis a lot during the past years, for all my OSS projects, and I have gotten very used to it.However, people seem to be &quot;abandoning&quot; travis in favor of GitHub Actions, for different reasons. &quot;It&#x27;s faster&quot;, &quot;I can run smaller tasks in parallel&quot;, etc.In my case, I have moved a few very specific tasks there, where travis was becoming a bottleneck, but I still have mixed feelings about the very-verbose yaml-based config needed to configure a few GitHub Actions, compared to the more concise travis one.In this article I&#x27;ll explain how I improved a travis build to run several smaller tasks in parallel jobs, without having to completely move away from it.<h3>Initial state</h3>This project&#x27;s travis config is relatively simple. It is used to build a JS project for the web browser, and it has to run the next tasks:<ul><li>Lint the code, to make sure it fulfils the project&#x27;s coding standards.</li><li>Run unit tests.</li><li>Run mutation tests.</li><li>Build the docker image, to make sure none of the new changes broke it.</li><li>Conditionally publish a release on GitHub, with a dist file attached to it, if the build is being run for a git tag.</li></ul><pre><pre><code class="language-yaml">dist: bionic

language: node_js

branches:
 only:
 - /.*/

cache:
 directories:
 - node_modules

services:
 - docker

node_js:
 - &#x27;12.16.3&#x27;

install: npm ci

before_script:
 - echo &quot;Building commit range ${TRAVIS_COMMIT_RANGE}&quot;
 - export MUTATION_FILES=$(git diff ${TRAVIS_COMMIT_RANGE:-origin/main} --name-only | grep -E &#x27;src\/(.*).(ts|tsx)$&#x27; | paste -sd &quot;,&quot;)

script:
 - npm run lint
 - npm run test:ci
 - npm run mutate:ci
 - docker build -t project:test .

after_success:
 - node_modules/.bin/ocular coverage/clover.xml

before_deploy: npm run build ${TRAVIS_TAG#?}

deploy:
 - provider: releases
 api_key:
 secure: &lt;key&gt;
 file: &quot;./dist/project_${TRAVIS_TAG#?}_dist.zip&quot;
 skip_cleanup: true
 on:
 tags: true
</code></pre></pre><h3>Problems with this approach</h3>This is more or less ok, but the last two commands in <code>script</code> can be relatively slow and can delay the whole process.Also, specially the mutation tests one, which is currently always considered successful regardless the result, can make the build reach the maximum run time allowed by travis, making the whole build falsely fail.<blockquote>The reason for the <code>before_script</code> step is to determine which source code files changed, and run mutation tests on them only, in order to mitigate this.</blockquote>Other than this, the build config defines &quot;global&quot; customizations that are actually only used for some tasks:<ul><li>Running <code>npm ci</code> is not required for the <code>docker build</code> task.</li><li>Getting the <code>docker</code> service is not required by any of the other tasks.</li><li>Determining changed files is only used by the <code>mutation tests</code> task.</li></ul><h3>Making use of jobs</h3>One cool feature travis supports is the use of a job <a target="_blank" rel="noopener noreferrer" href="https://docs.travis-ci.com/user/build-matrix/">build matrix</a>, that lets you define multiple jobs that run in parallel as part of the same build, and make each one of them do unrelated tasks.Using this feature it is possible to improve the <code>.travis.yml</code> file, making it look like this:<pre><pre><code class="language-yaml">dist: bionic

language: node_js

branches:
 only:
 - /.*/

cache:
 directories:
 - node_modules

node_js:
 - &#x27;12.16.3&#x27;

jobs:
 fast_finish: true
 allow_failures:
 - name: &#x27;Mutation tests&#x27;
 include:

 - name: &#x27;Lint&#x27;
 install: npm ci
 script: npm run lint

 - name: &#x27;Unit tests&#x27;
 install: npm ci
 script: npm run test:ci
 after_success:
 - node_modules/.bin/ocular coverage/clover.xml

 - name: &#x27;Mutation tests&#x27;
 install: npm ci
 before_script:
 - echo &quot;Building commit range ${TRAVIS_COMMIT_RANGE}&quot;
 - export MUTATION_FILES=$(git diff ${TRAVIS_COMMIT_RANGE:-origin/main} --name-only | grep -E &#x27;src\/(.*).(ts|tsx)$&#x27; | paste -sd &quot;,&quot;)
 script: npm run mutate:ci

 - name: &#x27;Build docker image&#x27;
 services:
 - docker
 install: skip
 script: docker build -t project:test .

 - name: &#x27;Publish release&#x27;
 if: tag IS present
 install: skip
 script: skip
 before_deploy: npm run build ${TRAVIS_TAG#?}
 deploy:
 - provider: releases
 api_key:
 secure: &lt;key&gt;
 file: &quot;./dist/project_${TRAVIS_TAG#?}_dist.zip&quot;
 skip_cleanup: true
 on:
 tags: true
</code></pre></pre>This approach introduces all these benefits:<ul><li>Now linting, testing, mutation testing and building the docker image run in parallel, making the build finish earlier.</li><li>The mutation testing step is allowed to fail, and thanks to the <code>fast_finish</code> flag, travis won&#x27;t even wait for it to finish, considering the build successful once the rest have passed.</li><li>Configs that are only meaningful for certain jobs are defined in the job itself, instead of globally.</li><li>The &quot;publish release&quot; job only runs conditionally if the build is for a tag, thanks to the <code>if: tag IS present</code> condition. (More info about <a target="_blank" rel="noopener noreferrer" href="https://docs.travis-ci.com/user/conditional-builds-stages-jobs/">conditional jobs</a> in travis).</li><li>As soon as any of the jobs fails, the whole build fails and you don&#x27;t have to continue waiting. Before this, if the third task failed, you still had to wait for the previous two to finish.</li><li>Each job can have a name, making it more clear in travis UI what tasks are being run:</li></ul><img src="/assets/img/travis-multiple-jobs/travis-jobs.png" alt="Travis CI jobs"/><h3>Conclusion</h3>The main purpose of this article was to showcase that travis still has a lot to give. Github Actions are definitely cool, but there&#x27;s usually no silver bullet for everything, and a combination with other tools might be more suitable.Also, this allows people using travis to improve their builds without having to change everything. Then, once you have split your tasks, if you still want to move to Github Actions, it should be easier.<blockquote>If you are curious, this is the project in which I use this travis configuration: <a target="_blank" rel="noopener noreferrer" href="https://github.com/shlinkio/shlink-web-client">shlinkio/shlink-web-client</a>.</blockquote>

Running several steps of a Travis CI build in parallel

There&#x27;s no doubt that having tests in a project allows you to find potential bugs earlier and more easily.Lots of OSS projects require a minimum code coverage in order to accept new pull requests from contributors, and proprietary projects also tend to have some sort of continuous integration workflow which requires certain metrics to be fulfilled in order to get builds passing.However, the code coverage can lead to a false sense of security, which makes you think that if certain class has a 100% code coverage, it is also 100% bug-free.This is not always true, since you could be calling a method and yet not being properly testing its output or its real behavior. The code coverage will mark it as covered, but you might introduce a bug and still have a green test.This is where mutation testing comes in.<h3>Mutation testing</h3>According to <a target="_blank" rel="noopener noreferrer" href="https://en.wikipedia.org/wiki/Mutation_testing">wikipedia</a>, mutation testing involves applying small modifications to a software. These modifications are called mutations.Then, if you pass your tests and any of them fails because of this &quot;mutation&quot;, then you have &quot;killed the mutant&quot;. This is what should happen in code which is covered by tests. If tests keep passing after applying this modification, then your tests covering that part of the project are not so good, and you should improve them to really test what they are covering.So in other words, mutation testing is a quality assurance practice for your tests.In PHP projects, there used to be one library which purpose was working with the mutation testing approach, <a target="_blank" rel="noopener noreferrer" href="https://github.com/humbug/humbug">humbug/humbug</a>. However, it is mostly abandoned now, and it has motivated the appearance of another project, <a target="_blank" rel="noopener noreferrer" href="https://infection.github.io/">infection/infection</a>.<h3>Infection</h3>Infection is a mutation testing framework for PHP.It is easy to start using it in your project, since you just need to install it (<code>composer require infection/infection --dev</code>), and create a configuration file. Then, it uses your existing test suite in order to apply mutations to your code and check your tests.It currently integrates with <a target="_blank" rel="noopener noreferrer" href="https://github.com/sebastianbergmann/phpunit/">phpunit</a> and <a target="_blank" rel="noopener noreferrer" href="https://github.com/phpspec/phpspec">phpspec</a>, but I suppose there will be compatibility with other testing frameworks in the future.<h4>Configuring infection</h4>It consumes an <code>infection.json</code> configuration file which could have a structure like this:<pre><pre><code class="language-json">{
 &quot;source&quot;: {
 &quot;directories&quot;: [
 &quot;module/*/src&quot;
 ]
 },
 &quot;timeout&quot;: 10,
 &quot;logs&quot;: {
 &quot;text&quot;: &quot;build/infection/infection-log.txt&quot;,
 &quot;summary&quot;: &quot;build/infection/summary-log.txt&quot;,
 &quot;debug&quot;: &quot;build/infection/debug-log.txt&quot;
 },
 &quot;tmpDir&quot;: &quot;build/infection/temp&quot;,
 &quot;phpUnit&quot;: {
 &quot;configDir&quot;: &quot;.&quot;
 }
}
</code></pre></pre>This is the configuration of one of my company&#x27;s projects. A modular application where every module is located inside the <code>module</code> directory and has its own <code>src</code> folder with source files.This config file basically defines where the sources are located, where infection&#x27;s logs should be placed, a temporary folder which will be used instead of using system&#x27;s default tmp folder, and where is the <code>phpunit.xml[.dist]</code> file.That&#x27;s all you need to get infection working.<blockquote>You can find detailed information of all the configuration options <a target="_blank" rel="noopener noreferrer" href="https://infection.github.io/guide/usage.html#Configuration">here</a></blockquote><h4>Running infection</h4>Now that we have the configuration file, we just need to run <code>vendor/bin/infection</code>, and it will execute our test suite and then apply mutations to our source files.Then it will display the result, telling how many mutants have been killed.Infection supports lots of mutators, like replacing <code>++</code> by <code>--</code>, <code>true</code> by <code>false</code>, changing method visibilities, return values, etc. You can find the whole list <a target="_blank" rel="noopener noreferrer" href="https://infection.github.io/guide/mutators.html">here</a>.The command line tool supports a list of modifiers, some of which are very interesting. This is how I would recommend you to run it if you want to address the whole project.<code>vendor/bin/infection --threads=4 --min-msi=70 --only-covered --log-verbosity=2</code>.<ul><li><code>--threads</code>: It runs tests and mutators in parallel processes, so you can take advantage of all the cores in your machine. Set a value that makes sense your you. If you have 8 cores, maybe you want to set it with value 8.</li><li><code>--min-msi</code>: This flag makes the process fail if the number of killed mutants is below certain percentage. In this case we require 70% of mutants to be killed. Adapt the value to your needs, and try to gradually improve your tests and increase this value (MSI stands for Mutation Score Indicator). This flag is really useful in continuous integration environments.</li><li><code>--only-covered</code>: This makes infection address only covered code. We know mutants won&#x27;t be killed in uncovered code, so I think it makes no sense to apply mutators there. I prefer to separate the required code coverage metric from the required mutation score indicator metric.</li><li><code>--log-verbosity</code>: By default, infection logs all the mutations it has applied to your code. This could lead to a log with thousands of lines if the project is big, so I prefer to set the log verbosity to 2, which makes it log only non-killed mutants.</li></ul>And that&#x27;s mainly it. You can now automate this task in your continuous integration pipeline, or just run it locally, but at least you will discover some parts both in your source files and your tests that can be improved.<h3>Troubleshooting</h3>While this could be enough for an introduction to infection, the title of this article says something about big projects, so I&#x27;m going to explain how we integrated infection in one of my company&#x27;s biggest projects and how we addressed some inherent problems.<h4>Already unstable</h4>The first problem while working with infection is that, at the moment of writing this article, it&#x27;s not in a stable version yet. That means you could find bugs.We found one in which infection wasn&#x27;t properly parsing our phpunit config file and it was excluding almost the whole project from the code coverage report. This caused all mutations to be skipped.We reported it and they fixed it very fast, but they haven&#x27;t tagged a version including the fix yet, so we require one specific commit from master while we wait for v0.8 to be released.<h4>Time consuming</h4>Another problem is that infection consumes a lot of memory and CPU, and takes a lot of time to be run when you have a lot of classes and tests.For example, our project has around 1500 unit tests, which take about 1&#x27;5min-2min to be run. Our build process also passes some coding style checks and functional repository tests. It usually takes about 3 minutes.The first time we run infection for the whole project, it took more than 16 minutes. That would make a build which is taking 3 minutes to take almost 20 minutes from now on, which is not an option because our build is run a lot of times every day.Our solution was making the build run infection only on changed sources, taking advantage of infection&#x27;s <code>--filter</code> flag, which lets you pass a comma-separated list of files and it gets applied only to them.The way in which we find which files have changed from previous build is by making a <code>git diff</code> between a commit from previous successful build and the new commit after updating the branch in which the build is being run (the commit identifiers are defined by jenkins&#x27; GIT plugin as environment variables).If it is the first time the build is run for this branch, we make the diff with <code>origin/develop</code> instead.The result is a bash script like this:<pre><pre><code class="language-bash"># Get files which have changed from latest processed commit, including only those inside sources
# If there&#x27;s no previous commit, diff with develop
INFECTION_FILTER=$(git diff ${GIT_PREVIOUS_SUCCESSFUL_COMMIT:-origin/develop} $GIT_COMMIT --name-only | grep /src/ | paste -sd &quot;,&quot; -)

# Check mutations over those files, if any, and require a 70% MSI
if [ -n &quot;$INFECTION_FILTER&quot; ]; then
 vendor/bin/infection --threads=4 --min-msi=70 --only-covered --log-verbosity=2 --filter=&quot;${INFECTION_FILTER}&quot;
else
 echo &quot;No source files affected. Infection skipped.&quot;
fi
</code></pre></pre>As you can see, we perform a diff by including only file names, then we exclude those which do not contain &quot;/src/&quot; as part of the name, and then we convert them into a comma-separated list.With this approach, the build usually takes 1 extra minute in the worst case scenario, which can be assumed.However, I&#x27;m sure the performance of this project will be improved as it grows and gets more stable.<h4>Test run duplication</h4>While previous approach filters the files where mutations are applied, it is still running all tests beforehand, which makes all tests to be run twice on every build.<ul><li>First, our own execution, which generates a code coverage report to be published later, and makes the build fail if tests do not pass.</li><li>Then, infection runs tests again, on its own &quot;conditions&quot; (they take your phpunit config file and generate a new one, which has some custom configuration entries).</li></ul><strike>If it were possible to pass infection an already generated code coverage, we could prevent this duplication, but, as far as I know, it does not support that.</strike> **It does now**.Another solution would be being able to run only tests which affect changed sources, instead of running all tests suites, but phpunit does not allow to filter by a list of files, only a specific file or folder.<strike>This is the only problem for which we have not yet found a solution, so If you know any workaround, a comment will be very welcome :-)</strike>Update 2018-02-22Following what Maks suggested in this <a href="/#comment-3762900802">comment</a>, we have changed the process a little bit, and using a more recent commit from <code>dev-master</code>, we can take advantage of a feature which allows an existing code coverage to be passed to infection.Now, our phpunit execution includes these two flags: <code>--coverage-xml=build/coverage-xml --log-junit=build/phpunit.junit.xml</code>And then, infection is executed with <code>--coverage=build</code>.That&#x27;s it, no need to run tests twice anymore :-)<h4>Xdebug vs phpdbg</h4>Since infection needs access to a code coverage report, you need some tool which is capable of generating it.People usually use xdebug, since it is the most extended and feature-rich debugging tool.However, there&#x27;s a simpler tool, which is designed to debug php console executions only, and comes bundled with php. It is <a target="_blank" rel="noopener noreferrer" href="https://github.com/krakjoe/phpdbg">phpdbg</a>.In our project, it usually takes 30%-50% less time to generate a code coverage report than xdebug. The result is not 100% the same, but it is very similar, and it&#x27;s worth it.So, instead of running infection like this:<pre><pre><code>vendor/bin/infection --threads=4 --min-msi=70 --only-covered --log-verbosity=2 --filter=&quot;${INFECTION_FILTER}&quot;
</code></pre></pre>We have to do it like this<pre><pre><code>phpdbg -qrr vendor/bin/infection --threads=4 --min-msi=70 --only-covered --log-verbosity=2 --filter=&quot;${INFECTION_FILTER}&quot;
</code></pre></pre>It is explained in <a target="_blank" rel="noopener noreferrer" href="https://infection.github.io/guide/usage.html#Running-with-phpdbg">infection&#x27;s docs</a>.We have even started to use it to run our own phpunit execution.<h3>Conclusion</h3>We have seen how to use infection, and how to integrate it in a continuous integration pipeline, even for big projects.I think it is a very useful tool, and the team behind it is doing a great job. It is also not hard to start using it, since you don&#x27;t really need to write new code, just add a config file and run the CLI tool.Finally, I recommend you to read this article, from infection&#x27;s author. It explains how it internally works, and how to use it in a development workflow <a target="_blank" rel="noopener noreferrer" href="https://medium.com/@maks_rafalko/infection-mutation-testing-framework-c9ccf02eefd1">https://medium.com/@maks_rafalko/infection-mutation-testing-framework-c9ccf02eefd1</a>.

Mutation testing with infection in big PHP projects

<a target="_blank" rel="noopener noreferrer" href="https://getcomposer.org/">Composer</a> is The Tool in any modern PHP project. Nowadays I can&#x27;t imagine to work without it.It is much more powerful than some people think, easily solving the integration of third party components in our projects, but there are some advanced features that are less known.I&#x27;m going to try to explain some of the best practices and mechanisms bundled with composer.<blockquote>If you are not familiar with composer, some time ago I wrote an introduction article that you should read before continuing with this one. <a href="/2014/07/19/dependency-management-and-autoloading-in-php-projects-with-composer/">Dependency management and autoloading in php projects with composer</a>.</blockquote><h3>Globally installing composer</h3>It is a good practice to have composer installed globally, instead of having a binary file per project.After downloading the <code>composer.phar</code> file from the <a target="_blank" rel="noopener noreferrer" href="https://getcomposer.org/download/">composer</a> website, you can start using it by running <code>php composer.phar [...]</code>. Instead, we are going to place it in a global location so that we can run the command <code>composer [...]</code> from this moment on.In UNIX systems, just make the file executable and move it to a folder that&#x27;s already in the path.<pre><pre><code class="language-bash">sudo chmod +x composer.phar
sudo mv composer.phar /usr/local/bin/composer
</code></pre></pre>Under Windows systems, there is an installer that will make the work for you. Download it <a target="_blank" rel="noopener noreferrer" href="https://getcomposer.org/doc/00-intro.md#installation-windows">here</a>.Now, go to any location and run <code>composer</code>. You should see composer&#x27;s help.<h3>Create the composer.json file</h3>The first thing you should do when starting a new PHP project is to create the composer.json file. It is the main configuration file, where metadata, dependencies and autoloading are defined.You probably don&#x27;t remember the main parts of this file, and end up copying the file from othe projects. There is no need to do that, just run <code>composer init</code> and the Composer config generator will be executed, guiding you over the process of creating the file.<h3>Add dependencies to an existing composer.json file</h3>In the documentation of many libraries, they tell you to manually edit your composer.json file to add new dependencies. That can be problematic, because you could have a syntax error, forget to add a trailing comma, etc.The best practice to add dependencies to your composer.json file is to run the command <code>composer require vendor-name/library-name ~3.0</code>. That will add the new dependency to your file (avoiding syntax errors) and then install it.If you don&#x27;t include the version name, composer will try to find out what&#x27;s the best version to use, by following <a target="_blank" rel="noopener noreferrer" href="http://semver.org/">Semantic Versioning</a>. If it is not able to know which version to use, it will ask you to decide.<h3>Production environments</h3>The management of dependencies and new classes is not the same in our development environment and the production environment. In development we need new classes to be automatically autoloaded, and we want to have certain dependencies, like phpunit or php code sniffer that are not of any use in production.In development we will usually install or update dependencies by running <code>composer install</code> or <code>composer update</code>. That will include all dependencies in require and require-dev blocks, and generate an autoloader by following different strategies. Some of those autoloading strategies imply the iteration of directories in order to find class files.That is ok for development, but in production we need something more efficient than that, and also, we don&#x27;t want require-dev dependencies to be installed.To get this done, in a deployment process, we should run this command instead.<pre><pre><code class="language-bash">composer install --no-dev --optimize-autoloader --prefer-dist --no-interaction
</code></pre></pre>This is what each flag makes:<ul><li><code>--no-dev</code>: prevents dependencies defined in the requre-dev block to be installed.</li><li><code>--optimize-autoloader</code>: generates a classmap autoloader, that will map each class with the file that contains it, preventing unnecessary directory iterations.</li><li><code>--prefer-dist</code>: installs distributable versions of the libraries, instead of source code, when possible.</li><li><code>--no-interaction</code>: will always try to make the proper decission in case any &quot;conflict&quot; is produced, so that the process is completly unatended.</li></ul>This is the command you should use when deploying a project, just after clonning a clean repository.<h3>Private repositories</h3>This is probably one of the most powerful features while working on many private projects that depend on each other.By default, composer fetches dependencies from a single repository, <a target="_blank" rel="noopener noreferrer" href="https://packagist.org/">Packagist</a>, which needs to have access to a public repository (usually github). But what happens if my code is private, and I don&#x27;t want to (or can&#x27;t) open source it? May I use composer to install private dependencies? The answer is yes.The composer.json file can include a repositories block, where we define other repositories (either public or private) where composer will try to find dependencies.There are several repository types supported by composer, from a VCS repository to a plain local directory containing zip files.<pre><pre><code class="language-javascript">{
 &quot;repositories&quot;: [
 {
 &quot;type&quot;: &quot;vcs&quot;,
 &quot;url&quot;: &quot;https://my-repos.com/something-private&quot;
 },
 {
 &quot;type&quot;: &quot;pear&quot;,
 &quot;url&quot;: &quot;http://pear2.php.net&quot;
 },
 {
 &quot;type&quot;: &quot;artifact&quot;,
 &quot;url&quot;: &quot;path/to/directory/with/zips/&quot;
 }
 ]
}
</code></pre></pre>Composer will look for dependencies on each defined repository in order, and Packagist as a last resource.Defining repositories is very flexible and a little bit complex in some cases, so I recommend you to read the <a target="_blank" rel="noopener noreferrer" href="https://getcomposer.org/doc/05-repositories.md">documentation</a>.<h3>CLI scripts</h3>Sometimes a library includes some command line interface scripts that the user can use to automate configuring some stuff.If you want to include your own CLI scripts and allow any user to find them when installing your library as a dependency, you will want to define them in the bin block.<pre><pre><code class="language-javascript">{
 &quot;bin&quot;: [
 &quot;scripts/generate-foo&quot;,
 &quot;scripts/create-bar&quot;,
 &quot;scripts/do-something&quot;
 ]
}
</code></pre></pre>It is just a list of script paths that composer will &quot;copy&quot; to the <code>vendor/bin</code> directory after installation (it doesn&#x27;t really copy them, it creates symlinks in UNIX systems and generates bat files under Windows).This makes all the CLI scripts of all dependencies to be &quot;placed&quot; in the same location, so it is easier to find them.This makes sense only in non-root projects (those that will be installed as dependencies of other projects and are not base applications).<h3>Events</h3>Composer will trigger some events during the process of installing dependencies, generating autoloaders and such. You can define some scripts or code snippets that will be automatically executed when those events are triggered.These event listeners are defined in the scripts block. They can be either CLI commands or static class methods.<pre><pre><code class="language-javascript">{
 &quot;scripts&quot;: {
 &quot;post-package-install&quot;: &quot;Acelaya\\MyClass::postPkgInstall&quot;,
 &quot;post-install-cmd&quot;: [
 &quot;Acelaya\\MyClass::postInstall&quot;,
 &quot;phpunit -c app/&quot;
 ]
 }
}
</code></pre></pre>The complete list of events can be found in composer&#x27;s <a target="_blank" rel="noopener noreferrer" href="https://getcomposer.org/doc/articles/scripts.md#event-names">documentation</a>. Take a look at them and see if you can optimize your workflow.<h3>Applications installation</h3>At this point we all know that we can use composer to install libraries at project level, but what happens with applications, known as root projects in composer&#x27;s terms.We can also use composer to distribute complete applications, allowing them to be easily installed by using this command.<pre><pre><code class="language-bash">composer create-project vendor-name/app-name
</code></pre></pre>This will download the application (as if we would have cloned the repository) and then install its dependencies. We could even take advantage of composer&#x27;s events, and initialize a database or create some non-tracked directories.<h3>Conclusion</h3>And that&#x27;s pretty much all.Use composer, it will improve your PHP projects.

Composer advanced concepts

One of the common problems we have to confront when starting a new PHP project is how to handle the different dependencies we are going to have.One could think the easier solution is to download all the libraries we are going to need, put them in a <code>lib</code> directory and add them to the version control of the project, but this could be problematic. Let&#x27;s see why.The main problems of using this practice are this.<ul><li>Dependencies of dependencies: Our dependencies may have their own dependencies that we will also need to download.</li><li>Updates: What happens if we need a new feature in the last version of one dependendency? We are going to have to update it manually, and that can be a hard task. Baybe even the new version has new dependencies of its own that we will need to download.</li><li>Autoloading: How do we deal with autoloading the classes in the dependencies? Some of them may have its own autoloading system, but anyway, we are going to need to <code>include</code> all the autoloaders of each dependency.</li></ul>How do we solve all of this? The answer is <a target="_blank" rel="noopener noreferrer" href="http://getcomposer.org">Composer</a>.<h3>Starting with composer</h3>Composer has become the dependency manager in the main PHP projects. It uses its own library repository (<a target="_blank" rel="noopener noreferrer" href="https://packagist.org/">packagist</a>) to handle dependencies, but you can setup private repositories too.It uses a small configuration file, the <code>composer.json</code>, to know which are our dependencies, and it will download their dependencies recursively without us having to do anything special.We can define an autoloading strategy in that file too, and forget about that task for our project and our dependencies.This are some examples of famous PHP project&#x27;s <code>composer.json</code> files:<ul><li><a target="_blank" rel="noopener noreferrer" href="https://github.com/zendframework/zf2/blob/master/composer.json">Zend Framework</a></li><li><a target="_blank" rel="noopener noreferrer" href="https://github.com/symfony/symfony/blob/master/composer.json">Symfony</a></li><li><a target="_blank" rel="noopener noreferrer" href="https://github.com/doctrine/doctrine2/blob/master/composer.json">Doctrine</a></li><li><a target="_blank" rel="noopener noreferrer" href="https://github.com/aws/aws-sdk-php/blob/master/composer.json">AWS PHP SDK</a></li><li><a target="_blank" rel="noopener noreferrer" href="https://github.com/Seldaek/monolog/blob/master/composer.json">Monolog</a></li><li><a target="_blank" rel="noopener noreferrer" href="https://github.com/thephpleague/flysystem/blob/master/composer.json">Flysystem</a></li></ul>Now lets see a simpler composer file:<pre><pre><code class="language-json">{
 &quot;name&quot; : &quot;acelaya/zf2-acmailer&quot;,
 &quot;description&quot; : &quot;Mail sending module for Zend Framework 2&quot;,
 &quot;type&quot; : &quot;library&quot;,
 &quot;authors&quot; : [
 {
 &quot;name&quot; : &quot;Alejandro Celaya Alastrué&quot;,
 &quot;email&quot; : &quot;alejandro@alejandrocelaya.com&quot;,
 &quot;homepage&quot; : &quot;http://www.alejandrocelaya.com&quot;,
 &quot;role&quot; : &quot;Developer&quot;
 }
 ],
 &quot;keywords&quot; : [
 &quot;mail&quot;,
 &quot;zend&quot;,
 &quot;php&quot;
 ],
 &quot;homepage&quot; : &quot;https://github.com/acelaya/ZF2-AcMailer&quot;,
 &quot;license&quot; : [
 &quot;BSD&quot;
 ],
 &quot;require&quot; : {
 &quot;php&quot; : &quot;&gt;=5.3.0&quot;,
 &quot;zendframework/zendframework&quot;: &quot;&gt;=2.2.2&quot;
 },
 &quot;require-dev&quot;: {
 &quot;phpunit/phpunit&quot;: &quot;&gt;=3.7&quot;,
 &quot;squizlabs/php_codesniffer&quot;: &quot;1.*&quot;,
 &quot;phploc/phploc&quot;: &quot;*&quot;,
 &quot;pdepend/pdepend&quot; : &quot;1.1.0&quot;,
 &quot;phpmd/phpmd&quot; : &quot;1.4.*&quot;,
 &quot;sebastian/phpcpd&quot;: &quot;*&quot;,
 &quot;theseer/phpdox&quot;: &quot;0.6.5&quot;
 },
 &quot;autoload&quot; : {
 &quot;psr-0&quot; : {
 &quot;AcMailer&quot; : &quot;src/&quot;
 },
 &quot;classmap&quot; : [
 &quot;./Module.php&quot;
 ]
 }
}
</code></pre></pre>This is the composer file of my Zend Framework 2 module <a target="_blank" rel="noopener noreferrer" href="https://github.com/acelaya/ZF2-AcMailer">AcMailer</a>. Let&#x27;s explain it.The properties name, description, type, authors, keywords, homepage and license are just metadata to provide useful information to other users and ease finding the project in <a target="_blank" rel="noopener noreferrer" href="https://packagist.org/">packagist</a>.The require property is the place where we define our dependencies and the version we want to install. We can define here the minimum required PHP version and even the php modules we need (like <code>php-pdo</code>, <code>php-intl</code> and such).The require-dev property allows us to define other dependencies that won&#x27;t be necessery in a production environment, like testing or documentation tools.Finally the autoload property is where we define how our own classes are loaded. It is very easy to define a <code>psr-0</code> or <code>psr-4</code> autoloading strategy, but we can even define a <code>classmap</code> with a list of paths to files.<blockquote>You don&#x27;t have to remember the <code>composer.json</code> schema. You can interactively create it by running <code>php composer.phar init</code>.</blockquote><h3>Installing dependencies</h3>Once this is defined we just need the composer binary file (usually in phar format), that can be found <a target="_blank" rel="noopener noreferrer" href="https://getcomposer.org/download/">here</a>, and run <code>php composer.phar install</code>.This will create a <code>vendor</code> folder in the root of our project, download our dependencies there, the dependencies of our dependencies, and set-up an autoloader that will be able to load all our dependencies and our own classes as well.After this it&#x27;s enough with a single <code>include</code> statement to <code>vendor/autoload.php</code> to be able to access any class.If later in the project we need to update an existing dependency, add new dependencies or change the autoloading, we just need to update the information in the <code>composer.json</code> file and run <code>php composer.phar update</code> to update dependencies and autoloader.<blockquote>It is recommended to include the composer binary in the PATH to be able to run <code>composer</code> instead of <code>php composer.phar</code>.</blockquote><blockquote>If you are using a VCS like <a target="_blank" rel="noopener noreferrer" href="https://git-scm.com/">git</a> in your project you will probably want to ignore your <code>vendor</code> folder.</blockquote><h3>Advanced usages</h3>This should be enough to start working with composer, but it is a much more powerful tool with more features. It is not a bad idea to take a quick read to its <a target="_blank" rel="noopener noreferrer" href="https://getcomposer.org/doc/">documentation</a>, but let&#x27;s see the main advanced features.<ul><li>Classmap autoloader: By running <code>composer dumpautoload --optimize</code> we can generate a much faster autoloader which defines a class =&gt; file map array with all the classes handled by composer. This is the more suitable autoloader for production environments.</li><li>Production dependencies: If we include de modifier <code>--no-dev</code> while installing or updating dependencies, it will ignore (or remove) the require-dev dependencies. For example <code>composer update --no-dev</code></li><li>Private repositories: If you want to install dependencies from repositories other than <a target="_blank" rel="noopener noreferrer" href="https://packagist.org/">packagist</a>, you can do it by using the repositories property. It supports many types of repositories, from VCS to PEAR repositories. Complete documentation <a target="_blank" rel="noopener noreferrer" href="https://getcomposer.org/doc/05-repositories.md">here</a>.</li><li>Global packages: If you want to install dependencies globally, just add the <code>global</code> keyword before the <code>install</code> or <code>update</code>. That will install the dependencies in the <code>~/.composer/vendor</code> directory instead of installing them in the local <code>vendor</code> directory. For example <code>composer global update</code>.</li></ul>And that&#x27;s all you need to know to start working with composer.Update 2015-04-25: I&#x27;ve written an article addressing advanced concepts that is a good continuation to this one. <a href="/2015/04/25/composer-advanced-concepts/">Composer advanced concepts</a>.

Dependency management and autoloading in php projects with composer

Dependency management is very important in any kind of project. Any application will need to use third party libraries to avoid to reinvent the wheel.The problem is that getting each one of them from a different place takes time, and it&#x27;s not easy to be sure we get the correct version.To solve this in java projects we can use an automated dependency manager, like <a target="_blank" rel="noopener noreferrer" href="https://maven.apache.org/">Maven</a>, which is really a building system with dependcy management included. The problem with maven is that it could be hard to use, and not very intuitive.Instead of Maven, I rather prefer to use <a target="_blank" rel="noopener noreferrer" href="https://ant.apache.org/ivy/">Ivy</a>. It is a more simple and agile dependency management system, designed to be used with <a target="_blank" rel="noopener noreferrer" href="https://ant.apache.org/">Ant</a>, but it takes dependencies from Maven repositories, like <a target="_blank" rel="noopener noreferrer" href="https://mvnrepository.com/">Maven central</a>.<h3>Getting started</h3>To use Ivy we need to create an <code>ivy.xml</code> file in the project root directory. It will be used to define which dependencies are needed by our project, and will need to be downloaded at building time.This is the <a target="_blank" rel="noopener noreferrer" href="https://github.com/acelaya/subclient-subconnector">Subconnector</a> Ivy script.<pre><pre><code class="language-xml">&lt;ivy-module version=&quot;2.0&quot;&gt;
 &lt;info organisation=&quot;net.subclient&quot; module=&quot;subconnector&quot; /&gt;

 &lt;dependencies&gt;
 &lt;dependency org=&quot;junit&quot; name=&quot;junit&quot; rev=&quot;4.10&quot; /&gt;
 &lt;dependency org=&quot;com.google.code.gson&quot; name=&quot;gson&quot; rev=&quot;2.2.2&quot; /&gt;
 &lt;dependency org=&quot;log4j&quot; name=&quot;log4j&quot; rev=&quot;1.2.17&quot; /&gt;
 &lt;dependency org=&quot;org.apache.commons&quot; name=&quot;commons-lang3&quot; rev=&quot;3.1&quot;/&gt;
 &lt;/dependencies&gt;
&lt;/ivy-module&gt;
</code></pre></pre>As you can see, it is very simple. We just defined an info element with the basic project information, and a dependencies element with nested information of each of the dependencies of the project.For each one of them we have to know its organization, name and revision. With this we can be sure we will get the desired library and revision.But how do we know what to put in <code>org</code>, <code>name</code> and <code>rev</code> attributes? The <a target="_blank" rel="noopener noreferrer" href="https://mvnrepository.com/">maven central repository</a> webpage will help us with this.At the top search bar we can write the name of a library, for example gson. The first result corresponds to the gson artifacts in the maven central. By selecting the desired version we will get the dependency element for an Ivy script, as well as other dependency management systems, like Maven or <a target="_blank" rel="noopener noreferrer" href="https://gradle.org/">Gradle</a>.<img src="/assets/img/dependency.jpg" alt="Maven dependency example"/>We just need to copy and paste it. Nice and easy.<h3>Automate retrieving dependencies</h3>Once our Ivy script is ready, it is time to include retrieving dependencies in our building process. The easiest way to do it is to create an Ant target in our <code>build.xml</code> script, like this.<pre><pre><code class="language-xml">&lt;target name=&quot;retrieve-dependencies&quot;
 description=&quot;Retrieve dependencies with Apache IVY&quot;&gt;

 &lt;ivy:retrieve type=&quot;jar&quot; /&gt;

&lt;/target&gt;
</code></pre></pre>This will look for the ivy.xml script and download dependencies defined on it in a lib folder, but only binary jar files. If <code>type=&quot;jar&quot;</code> is removed, all docs, sources and binaries will be retrieved.Make sure to add Ivy binaries to Ant classpath to make it properly work. The <code>project</code> element in the build script will need also to look like this.<pre><pre><code class="language-xml">&lt;project basedir=&quot;.&quot; default=&quot;build&quot; name=&quot;Subconnector&quot; xmlns:ivy=&quot;antlib:org.apache.ivy.ant&quot;&gt;

 ...

&lt;/project&gt;
</code></pre></pre>Notice the <code>xmlns:ivy</code> attribute.Now we are ready to go.For an advanced Ivy configuration take a look at its <a target="_blank" rel="noopener noreferrer" href="https://ant.apache.org/ivy/history/2.3.0/index.html">official documentation</a>. It explains how to use custom repositories, how to set up a proxy server, how to change default local lib folder, etc.

Dependency management in Java projects with Ant and Ivy

<a target="_blank" rel="noopener noreferrer" href="http://nsis.sourceforge.net/Main_Page">NSIS</a> is a well known system used to create Windows installers for any type of application based on scripts.It is good system. Once we have defined our script we can automatically build it to create application installers in minutes, including creation of Windows register entries, installation folders, application shortcuts, etcThe problem is that only Windows binaries are officially provided to compile this kind of scripts. This can be a problem in a <a target="_blank" rel="noopener noreferrer" href="https://en.wikipedia.org/wiki/Continuous_integration">continuous integration</a> environment, where continuous integration servers use to be Linux based.At this article I am going to explain how to compile NSIS source code in Linux to get it working there and allow it to be invoked from automated tasks run in a continuous integration server.<h3>Download NSIS</h3>The first step is to download the windows distributable zip file and the source code. Both of them can be downloaded from their Sourceforge project: <a target="_blank" rel="noopener noreferrer" href="https://sourceforge.net/projects/nsis/files/?source=navbar">https://sourceforge.net/projects/nsis/files/?source=navbar</a>.At the moment of writing this article the last stable version is NSIS 2.46, so we will need to download nsis-2.46.zip and nsis-2.46-src.tar.bz2. We will put them in a folder were users who are going to need it are allowed to access. I am going to put it at <code>/home/alejandro/nsis</code>Now that we have downloaded both windwos distributable package and source code we are going to decompress them creating two folders, nsis-2.46 and nsis-2.46-src.<h3>System requirements</h3>NSIS official documentation says we need this tools to compile it:<ul><li>Python, version 1.6 or higher. I am using Python 2.7.3</li><li>Scons version 0.96.93 or higher. This application can be downloaded from their official website <a target="_blank" rel="noopener noreferrer" href="http://www.scons.org/download.php">http://www.scons.org/download.php</a></li><li>A C compiler, in our case <code>gcc</code> and <code>g++</code></li></ul>All of this tools can be easily installed from repository, and probably we already have some of them.The scons installer downloaded from their website comes in RPM format which could be a problem for systems not based in Ubuntu. For Debian I used the alien [<code>aptitude install alien</code>] tool, which converts RPM packages into DEB packages by running this command: <code>alien -k filename.rpm</code>Anyway, I uploaded the DEB resultant package for you to <a href="/assets/downloads/scons_2.3.0-1_all.deb_.zip">download</a> it.<h3>Compile NSIS</h3>Once all the requirements are clear we are going to compile the NSIS binary that is responsible for interpreting the scripts, the so called <code>makensis</code>.We have to be at the source code directory, in my case <code>/home/alejandro/nsis/nsis-2.46-src</code>, and we execute this command.<pre><pre><code>scons SKIPSTUBS=all SKIPPLUGINS=all SKIPUTILS=all SKIPMISC=all NSIS_CONFIG_CONST_DATA=no PREFIX=/path/where/distributable/was/extracted install-compiler
</code></pre></pre>Notice that install-compiler is an argument of the command that is placed at the end, and is not part of the distributable path.In my case, using my real path, the resulting command would be this:<pre><pre><code>scons SKIPSTUBS=all SKIPPLUGINS=all SKIPUTILS=all SKIPMISC=all NSIS_CONFIG_CONST_DATA=no PREFIX=/home/alejandro/nsis/nsis-2.46 install-compiler
</code></pre></pre>The execution of this command will compile the code, generating the <code>makensis</code> binary at the bin directory inside the distributable package folder, in my case <code>/home/alejandro/nsis/nsis-2.46/bin</code>.<h3>Test makensis and create an installer</h3>Now that we have makensis created its a good idea to make it available from anywhere, for example adding it to a bin directory, and make sure it can be executed.Using the paths from our example, running this commands will make the job.<pre><pre><code>chmod +x /home/alejandro/nsis/nsis-2.46/bin/makensis
ln -s /home/alejandro/nsis/nsis-2.46/bin/makensis /usr/local/bin/makensis
</code></pre></pre>Now it is time to test the command. Running <code>makensis</code> from anywhere should output something like this.<img src="/assets/img/nsis.png" alt="Nsis help"/>If we have an nsis script, runing the command makensis /path/to/script.nsi will compile the script, creating the installer. The syntax is the same used in windows.Atention! While running this command there could be this error.<pre><pre><code>Error: opening stub &quot;/home/alejandro/nsis/nsis-2.46/share/nsis/Stubs/zlib
Error initalizing CEXEBuild: error setting default stub
</code></pre></pre>This could happen because of a path error, but solving it is very simple, just go to the NSIS distributable folder, <code>/home/alejandro/nsis/nsis-2.46</code> in my case, and create the folder share [<code>mkdir share</code>], go to that folder an create a symbolic link running ln -s <code>/home/alejandro/nsis/nsis-2.46 nsis</code>.That should fix the problem.With this easy steps we have now a NSIS compilation system under a Linux machine ready to build and deploy Windows installers.

Alejandro Celaya | Blog

Software development, agile methodologies and open source projects.

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