New command useful to limit the amount of testing in a project

config/services.php

@@ -78,6 +78,8 @@
 use Qossmic\Deptrac\Core\Layer\LayerResolverInterface;
 use Qossmic\Deptrac\Supportive\Console\Command\AnalyseCommand;
 use Qossmic\Deptrac\Supportive\Console\Command\AnalyseRunner;
+use Qossmic\Deptrac\Supportive\Console\Command\ChangedFilesCommand;
+use Qossmic\Deptrac\Supportive\Console\Command\ChangedFilesRunner;
 use Qossmic\Deptrac\Supportive\Console\Command\DebugDependenciesCommand;
 use Qossmic\Deptrac\Supportive\Console\Command\DebugDependenciesRunner;
 use Qossmic\Deptrac\Supportive\Console\Command\DebugLayerCommand;
@@ -425,6 +427,13 @@
         ->set(AnalyseCommand::class)
         ->autowire()
         ->tag('console.command');
+    $services
+        ->set(ChangedFilesRunner::class)
+        ->autowire();
+    $services
+        ->set(ChangedFilesCommand::class)
+        ->autowire()
+        ->tag('console.command');
     $services
         ->set(DebugLayerRunner::class)
         ->autowire()

docs/debugging.md

@@ -76,3 +76,22 @@ $ php deptrac.phar debug:unused --limit=10
   InputCollector layer is dependent File layer 3 times
   OutputFormatter layer is dependent DependencyInjection layer 1 times
 ```
+
+## `changed-files`
+
+> [!CAUTION]
+> This command in experimental and is not covered by
+> the [BC policy](bc_policy.md).
+
+This command list the layers corresponding to the passed files. Optionally it
+can also list all the layers that depend on those layers.
+
+```console
+$ php deptrac.phar changed-files --with-dependencies src/Supportive/File/FileReader.php
+
+  File
+  Console;Ast;InputCollector;Analyser;Dependency;Layer
+```
+
+For a discussion as to why that information might be useful, refer to
+the [90DaysOfDevOps Presentation](https://github.com/MichaelCade/90DaysOfDevOps/pull/472).

phpunit.xml.dist

@@ -4,6 +4,36 @@
     <testsuite name="Tests">
       <directory suffix="Test.php">./tests/</directory>
     </testsuite>
+      <testsuite name="Contract">
+          <directory>./tests/Contract</directory>
+      </testsuite>
+      <testsuite name="Analyser">
+          <directory>./tests/Core/Analyser</directory>
+      </testsuite>
+      <testsuite name="Ast">
+          <directory>./tests/Core/Ast</directory>
+      </testsuite>
+      <testsuite name="Dependency">
+          <directory>./tests/Core/Dependency</directory>
+      </testsuite>
+      <testsuite name="InputCollector">
+          <directory>./tests/Core/InputCollector</directory>
+      </testsuite>
+      <testsuite name="Layer">
+          <directory>./tests/Core/Layer</directory>
+      </testsuite>
+      <testsuite name="Console">
+          <directory>./tests/Supportive/Console</directory>
+      </testsuite>
+      <testsuite name="DependencyInjection">
+          <directory>./tests/Supportive/DependencyInjection</directory>
+      </testsuite>
+      <testsuite name="File">
+          <directory>./tests/Supportive/File</directory>
+      </testsuite>
+      <testsuite name="OutputFormatter">
+          <directory>./tests/Supportive/OutputFormatter</directory>
+      </testsuite>
   </testsuites>
   <coverage cacheDirectory="./.cache/phpunit"/>
   <source>

src/Supportive/Console/Command/ChangedFilesCommand.php

@@ -0,0 +1,52 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Qossmic\Deptrac\Supportive\Console\Command;
+
+use Qossmic\Deptrac\Supportive\Console\Symfony\Style;
+use Qossmic\Deptrac\Supportive\Console\Symfony\SymfonyOutput;
+use Symfony\Component\Console\Command\Command;
+use Symfony\Component\Console\Input\InputArgument;
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Input\InputOption;
+use Symfony\Component\Console\Output\OutputInterface;
+use Symfony\Component\Console\Style\SymfonyStyle;
+
+class ChangedFilesCommand extends Command
+{
+
+    public static $defaultName = 'changed-files';
+    public static $defaultDescription = 'Lists layers corresponding to the changed files';
+
+    public function __construct(
+        private readonly ChangedFilesRunner $runner,
+    ) {
+        parent::__construct();
+    }
+
+    protected function configure(): void
+    {
+        parent::configure();
+        $this->addOption('with-dependencies', null, InputOption::VALUE_NONE, 'show dependent layers');
+        $this->addArgument('files', InputArgument::REQUIRED | InputArgument::IS_ARRAY, 'List of changed files');
+    }
+
+    protected function execute(InputInterface $input, OutputInterface $output): int
+    {
+        ini_set('memory_limit', '-1');
+
+        $symfonyOutput = new SymfonyOutput($output, new Style(new SymfonyStyle($input, $output)));
+
+        try {
+            /** @var list<string> $files */
+            $files = $input->getArgument('files');
+            $this->runner->run($files, (bool) $input->getOption('with-dependencies'), $symfonyOutput);
+        } catch (CommandRunException) {
+            return self::FAILURE;
+        }
+
+        return self::SUCCESS;
+    }
+
+}

src/Supportive/Console/Command/ChangedFilesRunner.php

@@ -0,0 +1,100 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Qossmic\Deptrac\Supportive\Console\Command;
+
+use Qossmic\Deptrac\Contract\OutputFormatter\OutputInterface;
+use Qossmic\Deptrac\Contract\Result\CoveredRuleInterface;
+use Qossmic\Deptrac\Contract\Result\OutputResult;
+use Qossmic\Deptrac\Contract\Result\RuleInterface;
+use Qossmic\Deptrac\Core\Analyser\AnalyserException;
+use Qossmic\Deptrac\Core\Analyser\DependencyLayersAnalyser;
+use Qossmic\Deptrac\Core\Analyser\LayerForTokenAnalyser;
+use Qossmic\Deptrac\Core\Analyser\TokenType;
+
+/**
+ * @internal Should only be used by ChangedFilesCommand
+ */
+final class ChangedFilesRunner
+{
+    public function __construct(
+        private readonly LayerForTokenAnalyser $layerForTokenAnalyser,
+        private readonly DependencyLayersAnalyser $dependencyLayersAnalyser
+    ) {}
+
+    /**
+     * @param list<string> $files
+     *
+     * @throws CommandRunException
+     */
+    public function run(array $files, bool $withDependencies, OutputInterface $output): void
+    {
+        try {
+            $layers = [];
+            foreach ($files as $file) {
+                $matches = $this->layerForTokenAnalyser->findLayerForToken($file, TokenType::FILE);
+                foreach ($matches as $match) {
+                    foreach ($match as $layer) {
+                        $layers[$layer] = $layer;
+                    }
+                }
+            }
+            $output->writeLineFormatted(implode(';', $layers));
+        } catch (AnalyserException $exception) {
+            throw CommandRunException::analyserException($exception);
+        }
+
+        if ($withDependencies) {
+            try {
+                $result = OutputResult::fromAnalysisResult($this->dependencyLayersAnalyser->analyse());
+                $layersDependOnLayers = $this->calculateLayerDependencies($result->allRules());
+
+                $layerDependencies = [];
+                foreach ($layers as $layer) {
+                    $layerDependencies += $layersDependOnLayers[$layer] ?? [];
+                }
+                do {
+                    $size = count($layerDependencies);
+                    $layerDependenciesCopy = $layerDependencies;
+                    foreach ($layerDependenciesCopy as $layerDependency) {
+                        $layerDependencies += $layersDependOnLayers[$layerDependency] ?? [];
+                    }
+                } while ($size !== count($layerDependencies));
+
+                $output->writeLineFormatted(implode(';', $layerDependencies));
+            } catch (AnalyserException $exception) {
+                throw CommandRunException::analyserException($exception);
+            }
+        }
+    }
+
+    /**
+     * @param RuleInterface[] $rules
+     *
+     * @return array<string, array<string, string>>
+     */
+    private function calculateLayerDependencies(array $rules): array
+    {
+        $layersDependOnLayers = [];
+
+        foreach ($rules as $rule) {
+            if (!$rule instanceof CoveredRuleInterface) {
+                continue;
+            }
+
+            $layerA = $rule->getDependerLayer();
+            $layerB = $rule->getDependentLayer();
+
+            if (!isset($layersDependOnLayers[$layerB])) {
+                $layersDependOnLayers[$layerB] = [];
+            }
+
+            if (!array_key_exists($layerA, $layersDependOnLayers[$layerB])) {
+                $layersDependOnLayers[$layerB][$layerA] = $layerA;
+            }
+        }
+
+        return $layersDependOnLayers;
+    }
+}