jwage · jwage · May 19, 2018 · May 19, 2018
diff --git a/README.md b/README.md
@@ -18,3 +18,19 @@ You can install with composer:
 Generate a change log based on a GitHub milestone with the following command:
 
     $ ./vendor/bin/changelog-generator generate --user=doctrine --repository=migrations --milestone=2.0
+
+### Write to File
+
+Write the generated changelog to a file with the `--file` option. If you don't provide a value, it will be written
+to the current working directory in a file named `CHANGELOG.md`:
+
+    $ ./vendor/bin/changelog-generator generate --user=doctrine --repository=migrations --milestone=2.0 --file
+
+You can pass a value to `--file` to specify where the changelog file should be written:
+
+    $ ./vendor/bin/changelog-generator generate --user=doctrine --repository=migrations --milestone=2.0 --file=changelog.md
+
+By default it will overwrite the file contents but you can pass the `--append` option to append the changelog to
+the existing contents.
+
+    $ ./vendor/bin/changelog-generator generate --user=doctrine --repository=migrations --milestone=2.0 --file=changelog.md --append
diff --git a/phpcs.xml.dist b/phpcs.xml.dist
@@ -14,6 +14,10 @@
 
     <rule ref="Doctrine"/>
 
+    <rule ref="Squiz.Classes.ClassFileName.NoMatch">
+        <exclude-pattern>*/tests/*</exclude-pattern>
+    </rule>
+
     <rule ref="PSR1.Classes.ClassDeclaration.MultipleClasses">
         <exclude-pattern>*/tests/*</exclude-pattern>
     </rule>

diff --git a/src/ChangelogGenerator/Command/GenerateChangelogCommand.php b/src/ChangelogGenerator/Command/GenerateChangelogCommand.php
@@ -5,10 +5,15 @@
 namespace ChangelogGenerator\Command;
 
 use ChangelogGenerator\ChangelogGenerator;
+use InvalidArgumentException;
 use Symfony\Component\Console\Command\Command;
 use Symfony\Component\Console\Input\InputInterface;
 use Symfony\Component\Console\Input\InputOption;
 use Symfony\Component\Console\Output\OutputInterface;
+use Symfony\Component\Console\Output\StreamOutput;
+use function fopen;
+use function getcwd;
+use function sprintf;
 
 class GenerateChangelogCommand extends Command
 {
@@ -51,6 +56,19 @@ protected function configure() : void
                 InputOption::VALUE_REQUIRED,
                 'The milestone to build the changelog for.'
             )
+            ->addOption(
+                'file',
+                null,
+                InputOption::VALUE_OPTIONAL,
+                'Write the changelog to a file.',
+                false
+            )
+            ->addOption(
+                'append',
+                null,
+                InputOption::VALUE_NONE,
+                'Append the changelog to the file.'
+            )
         ;
     }
 
@@ -60,6 +78,54 @@ protected function execute(InputInterface $input, OutputInterface $output) : voi
         $repository = $input->getOption('repository');
         $milestone  = $input->getOption('milestone');
 
-        $this->changelogGenerator->generate($user, $repository, $milestone, $output);
+        $changelogOutput = $this->getChangelogOutput($input, $output);
+
+        $this->changelogGenerator->generate($user, $repository, $milestone, $changelogOutput);
+    }
+
+    /**
+     * @return false|resource
+     */
+    protected function fopen(string $file, string $mode)
+    {
+        return fopen($file, $mode);
+    }
+
+    /**
+     * @throws InvalidArgumentException
+     */
+    protected function createStreamOutput(string $file, bool $append) : StreamOutput
+    {
+        $handle = $this->fopen($file, $this->getFileHandleMode($append));
+
+        if ($handle === false) {
+            throw new InvalidArgumentException(sprintf('Could not open handle for %s', $file));
+        }
+
+        return new StreamOutput($handle);
+    }
+
+    private function getFileHandleMode(bool $append) : string
+    {
+        return $append ? 'a+' : 'w+';
+    }
+
+    private function getChangelogOutput(InputInterface $input, OutputInterface $output) : OutputInterface
+    {
+        $file   = $input->getOption('file');
+        $append = (bool) $input->getOption('append');
+
+        $changelogOutput = $output;
+
+        if ($file !== false) {
+            $changelogOutput = $this->createStreamOutput($this->getChangelogFilePath($file), $append);
+        }
+
+        return $changelogOutput;
+    }
+
+    private function getChangelogFilePath(?string $file) : string
+    {
+        return $file === null ? sprintf('%s/CHANGELOG.md', getcwd()) : $file;
     }
 }
diff --git a/tests/ChangelogGenerator/Tests/Functional/ConsoleTest.php b/tests/ChangelogGenerator/Tests/Functional/ConsoleTest.php
@@ -6,44 +6,172 @@
 
 use ChangelogGenerator\ChangelogGenerator;
 use ChangelogGenerator\Command\GenerateChangelogCommand;
+use InvalidArgumentException;
 use PackageVersions\Versions;
 use PHPUnit\Framework\TestCase;
 use Symfony\Component\Console\Application;
 use Symfony\Component\Console\Input\ArrayInput;
 use Symfony\Component\Console\Output\OutputInterface;
+use Symfony\Component\Console\Output\StreamOutput;
+use function sprintf;
+use function sys_get_temp_dir;
+use function unlink;
 
 final class ConsoleTest extends TestCase
 {
     /** @var \PHPUnit_Framework_MockObject_MockObject|ChangelogGenerator */
     private $changelogGenerator;
 
+    /** @var \PHPUnit_Framework_MockObject_MockObject|GenerateChangelogCommand */
+    private $generateChangelogCommand;
+
     /** @var Application */
     private $application;
 
     public function testGenerate() : void
     {
         $input = new ArrayInput([
-            'command' => 'generate',
-            '--user' => 'jwage',
-            '--repository' => 'changelog-generator',
-            '--milestone' => '1.0',
+            'command'       => 'generate',
+            '--user'        => 'jwage',
+            '--repository'  => 'changelog-generator',
+            '--milestone'   => '1.0',
         ]);
 
         $output = $this->createMock(OutputInterface::class);
 
         $this->changelogGenerator->expects($this->once())
             ->method('generate')
-            ->with('jwage', 'changelog-generator', '1.0');
+            ->with('jwage', 'changelog-generator', '1.0', $output);
 
         $this->application->run($input, $output);
     }
 
+    public function testGenerateFile() : void
+    {
+        $input = new ArrayInput([
+            'command'       => 'generate',
+            '--user'        => 'jwage',
+            '--repository'  => 'changelog-generator',
+            '--milestone'   => '1.0',
+            '--file'        => null,
+        ]);
+
+        $output       = $this->createMock(OutputInterface::class);
+        $streamOutput = $this->createMock(StreamOutput::class);
+
+        $this->generateChangelogCommand->expects($this->once())
+            ->method('createStreamOutput')
+            ->willReturn($streamOutput);
+
+        $this->changelogGenerator->expects($this->once())
+            ->method('generate')
+            ->with('jwage', 'changelog-generator', '1.0', $streamOutput);
+
+        $this->application->run($input, $output);
+    }
+
+    public function testGenerateFilePathGiven() : void
+    {
+        $input = new ArrayInput([
+            'command'       => 'generate',
+            '--user'        => 'jwage',
+            '--repository'  => 'changelog-generator',
+            '--milestone'   => '1.0',
+            '--file'        => 'CHANGELOG.md',
+        ]);
+
+        $output       = $this->createMock(OutputInterface::class);
+        $streamOutput = $this->createMock(StreamOutput::class);
+
+        $this->generateChangelogCommand->expects($this->once())
+            ->method('createStreamOutput')
+            ->willReturn($streamOutput);
+
+        $this->changelogGenerator->expects($this->once())
+            ->method('generate')
+            ->with('jwage', 'changelog-generator', '1.0', $streamOutput);
+
+        $this->application->run($input, $output);
+    }
+
+    public function testGenerateFileAppend() : void
+    {
+        $input = new ArrayInput([
+            'command'       => 'generate',
+            '--user'        => 'jwage',
+            '--repository'  => 'changelog-generator',
+            '--milestone'   => '1.0',
+            '--file'        => 'CHANGELOG.md',
+            '--append'      => true,
+        ]);
+
+        $output       = $this->createMock(OutputInterface::class);
+        $streamOutput = $this->createMock(StreamOutput::class);
+
+        $this->generateChangelogCommand->expects($this->once())
+            ->method('createStreamOutput')
+            ->willReturn($streamOutput);
+
+        $this->changelogGenerator->expects($this->once())
+            ->method('generate')
+            ->with('jwage', 'changelog-generator', '1.0', $streamOutput);
+
+        $this->application->run($input, $output);
+    }
+
+    public function testCreateStreamOutput() : void
+    {
+        $generateChangelogCommand = new GenerateChangelogCommandStub($this->changelogGenerator);
+
+        $file = sprintf('%s/test.md', sys_get_temp_dir());
+
+        self::assertInstanceOf(StreamOutput::class, $generateChangelogCommand->createStreamOutputTest($file, true));
+        self::assertInstanceOf(StreamOutput::class, $generateChangelogCommand->createStreamOutputTest($file, false));
+
+        unlink($file);
+    }
+
+    public function testCreateStreamOutputCouldNotOpenHandleInvalidArgumentException() : void
+    {
+        $this->expectException(InvalidArgumentException::class);
+        $this->expectExceptionMessage('Could not open handle for /tmp/test.md');
+
+        $file = sprintf('%s/test.md', sys_get_temp_dir());
+
+        /** @var \PHPUnit_Framework_MockObject_MockObject|GenerateChangelogCommandStub $generateChangelogCommand */
+        $generateChangelogCommand = $this->getMockBuilder(GenerateChangelogCommandStub::class)
+            ->setConstructorArgs([$this->changelogGenerator])
+            ->setMethods(['fopen'])
+            ->getMock();
+
+        $generateChangelogCommand->expects($this->once())
+            ->method('fopen')
+            ->with($file, 'a+')
+            ->willReturn(false);
+
+        $generateChangelogCommand->createStreamOutputTest($file, true);
+    }
+
     protected function setUp() : void
     {
         $this->changelogGenerator = $this->createMock(ChangelogGenerator::class);
 
         $this->application = new Application('Changelog Generator', Versions::getVersion('jwage/changelog-generator'));
         $this->application->setAutoExit(false);
-        $this->application->add(new GenerateChangelogCommand($this->changelogGenerator));
+
+        $this->generateChangelogCommand = $this->getMockBuilder(GenerateChangelogCommand::class)
+            ->setConstructorArgs([$this->changelogGenerator])
+            ->setMethods(['createStreamOutput'])
+            ->getMock();
+
+        $this->application->add($this->generateChangelogCommand);
+    }
+}
+
+class GenerateChangelogCommandStub extends GenerateChangelogCommand
+{
+    public function createStreamOutputTest(string $file, bool $append) : StreamOutput
+    {
+        return $this->createStreamOutput($file, $append);
     }
 }