Introduce results writer for json format

src/ComposerRequireChecker/Cli/ResultsWriter/JsonFile.php

@@ -0,0 +1,58 @@
+<?php
+
+declare(strict_types=1);
+
+namespace ComposerRequireChecker\Cli\ResultsWriter;
+
+use DateTimeImmutable;
+use RuntimeException;
+
+use function dirname;
+use function file_put_contents;
+use function function_exists;
+use function is_dir;
+use function json_encode;
+use function mkdir;
+use function sprintf;
+
+final class JsonFile implements ResultsWriter
+{
+    private string $filePathname;
+    private string $applicationVersion;
+
+    public function __construct(string $filePathname, string $applicationVersion)
+    {
+        if (! function_exists('json_encode')) {
+            throw new RuntimeException('Missing extension: json');
+        }
+
+        $this->filePathname       = $filePathname;
+        $this->applicationVersion = $applicationVersion;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function write(array $unknownSymbols): void
+    {
+        $filePath = dirname($this->filePathname);
+        if (! mkdir($filePath, 0777, true) && ! is_dir($filePath)) {
+            throw new RuntimeException(sprintf('Directory "%s" was not created', $filePath));
+        }
+
+        file_put_contents(
+            $this->filePathname,
+            json_encode(
+                [
+                    '_meta' => [
+                        'composer-require-checker' => [
+                            'version' => $this->applicationVersion,
+                        ],
+                        'date' => (new DateTimeImmutable())->format(DateTimeImmutable::ATOM),
+                    ],
+                    'unknown-symbols' => $unknownSymbols,
+                ],
+            )
+        );
+    }
+}

test/ComposerRequireCheckerTest/Cli/ResultsWriter/JsonFileTest.php

@@ -0,0 +1,56 @@
+<?php
+
+declare(strict_types=1);
+
+namespace ComposerRequireCheckerTest\Cli\ResultsWriter;
+
+use ComposerRequireChecker\Cli\ResultsWriter\JsonFile;
+use org\bovigo\vfs\vfsStream;
+use org\bovigo\vfs\vfsStreamDirectory;
+use PHPUnit\Framework\TestCase;
+
+use function file_get_contents;
+use function json_decode;
+
+final class JsonFileTest extends TestCase
+{
+    private JsonFile $writer;
+    private vfsStreamDirectory $root;
+
+    protected function setUp(): void
+    {
+        parent::setUp();
+
+        $this->root   = vfsStream::setup();
+        $this->writer = new JsonFile('vfs://root/path/name.json', '0.0.1');
+    }
+
+    public function testWriteReport(): void
+    {
+        $this->writer->write([
+            'Foo' => [],
+            'opcache_get_status' => ['ext-opcache'],
+            'dummy' => ['ext-dummy', 'ext-other'],
+        ]);
+
+        self::assertFileExists('vfs://root/path/name.json');
+
+        $actual                  = json_decode(file_get_contents('vfs://root/path/name.json'), true);
+        $actual['_meta']['date'] = 'ATOM_DATE';
+
+        self::assertSame(
+            [
+                '_meta' => [
+                    'composer-require-checker' => ['version' => '0.0.1'],
+                    'date' => 'ATOM_DATE',
+                ],
+                'unknown-symbols' => [
+                    'Foo' => [],
+                    'opcache_get_status' => ['ext-opcache'],
+                    'dummy' => ['ext-dummy', 'ext-other'],
+                ],
+            ],
+            $actual
+        );
+    }
+}