MO file loader

CHANGELOG.md

@@ -7,7 +7,7 @@ Updates should follow the [Keep a CHANGELOG](http://keepachangelog.com/) princip
 ## Unreleased
 
 ### Added
-- Nothing
+- Loader for MO files.
 
 ### Changed
 - Nothing

src/Loader/MoFileLoader.php

@@ -0,0 +1,102 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Stadly\Translation\Loader;
+
+use Symfony\Component\Translation\Exception\InvalidResourceException;
+use Symfony\Component\Translation\Loader\FileLoader;
+
+final class MoFileLoader extends FileLoader
+{
+    // phpcs:disable Squiz.Commenting.FunctionComment.ScalarTypeHintMissing
+    // phpcs:disable SlevomatCodingStandard.TypeHints.TypeHintDeclaration.MissingParameterTypeHint
+    /**
+     * Parses machine object (MO) format, independent of the machine's endian it
+     * was created on. Both 32bit and 64bit systems are supported.
+     *
+     * @param string $filename Path to resource to load.
+     * @return array<string|int, string> Strings loaded from resource.
+     */
+    protected function loadResource($filename): array
+    {
+        $stream = fopen($filename, 'r');
+        if ($stream === false) {
+            // @codeCoverageIgnoreStart
+            throw new InvalidResourceException('Could not open file.');
+            // @codeCoverageIgnoreEnd
+        }
+
+        $this->readLong($stream); // magicNumber
+        $this->readLong($stream); // formatRevision
+        $count = $this->readLong($stream);
+        $offsetId = $this->readLong($stream);
+        $offsetTranslated = $this->readLong($stream);
+        $this->readLong($stream); // sizeHashes
+        $this->readLong($stream); // offsetHashes
+
+        $messages = [];
+
+        for ($i = 0; $i < $count; ++$i) {
+            fseek($stream, $offsetId + $i * 8);
+            $id = $this->readEntry($stream);
+
+            fseek($stream, $offsetTranslated + $i * 8);
+            $translated = $this->readEntry($stream);
+
+            if ($id !== null && $translated !== null) {
+                $messages[$id] = $translated;
+            }
+        }
+
+        fclose($stream);
+
+        return $messages;
+    }
+    // phpcs:enable
+
+    /**
+     * Reads an unsigned long from stream.
+     *
+     * @param resource $stream Stream to read from.
+     * @return int The read number.
+     */
+    private function readLong($stream): int
+    {
+        $string = fread($stream, 4);
+        if ($string === false) {
+            // @codeCoverageIgnoreStart
+            throw new InvalidResourceException('Could not read from file.');
+            // @codeCoverageIgnoreEnd
+        }
+        if (strlen($string) !== 4) {
+            throw new InvalidResourceException('MO stream content has an invalid format.');
+        }
+        $number = unpack('V', $string);
+
+        return $number[1];
+    }
+
+    /**
+     * @param resource $stream Stream to read from.
+     * @return string|null The read entry or null on failure.
+     */
+    private function readEntry($stream): ?string
+    {
+        $length = $this->readLong($stream);
+        $offset = $this->readLong($stream);
+
+        if ($length < 1) {
+            return null;
+        }
+
+        fseek($stream, $offset);
+        $string = fread($stream, $length);
+        if ($string === false) {
+            // @codeCoverageIgnoreStart
+            throw new InvalidResourceException('Could not read from file.');
+            // @codeCoverageIgnoreEnd
+        }
+        return implode('|', explode("\000", $string));
+    }
+}

tests/Loader/MoFileLoaderTest.php

@@ -0,0 +1,89 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Stadly\Translation\Loader;
+
+use PHPUnit\Framework\TestCase;
+use Symfony\Component\Translation\Exception\InvalidResourceException;
+use Symfony\Component\Translation\Exception\NotFoundResourceException;
+
+/**
+ * @coversDefaultClass \Stadly\Translation\Loader\MoFileLoader
+ * @covers ::<protected>
+ * @covers ::<private>
+ */
+final class MoFileLoaderTest extends TestCase
+{
+    /**
+     * @covers ::load
+     */
+    public function testCanLoadFile(): void
+    {
+        $loader = new MoFileLoader();
+        $resource = __DIR__ . '/../resources/messages.mo';
+        $catalogue = $loader->load($resource, 'en_US', 'messages');
+
+        self::assertEquals([
+            'foo'
+                => 'bar',
+            'one foo|%count% foos'
+                => 'one bar|%count% bars',
+            '{0} no foos|one foo|%count% foos'
+                => '{0} no bars|one bar|%count% bars',
+            'missing foo plural|missing foo plurals'
+                => 'missing bar plural|',
+            'string containing || foo'
+                => 'string containing || bar',
+            'one string containing || foo|%count% strings containing || foos'
+                => 'one string containing || bar|%count% strings containing || bars',
+            '{0} no strings containing || foos|one string containing || foo|%count% strings containing || foos'
+                => '{0} no strings containing || bars|one string containing || bar|%count% strings containing || bars',
+            'escaped "foo"'
+                => 'escaped "bar"',
+            'one escaped "foo"|%count% escaped "foos"'
+                => 'one escaped "bar"|%count% escaped "bars"',
+            '{0} no escaped "foos"|one one escaped "foo"|%count% escaped "foos"'
+                => '{0} no escaped "bars"|one one escaped "bar"|%count% escaped "bars"',
+        ], $catalogue->all('messages'));
+    }
+
+    /**
+     * @covers ::load
+     */
+    public function testCannotLoadEmptyFile(): void
+    {
+        $loader = new MoFileLoader();
+        $resource = __DIR__ . '/../resources/empty.mo';
+
+        $this->expectException(InvalidResourceException::class);
+
+        $loader->load($resource, 'en_US', 'messages');
+    }
+
+    /**
+     * @covers ::load
+     */
+    public function testCannotLoadInvalidFile(): void
+    {
+        $loader = new MoFileLoader();
+        $resource = __DIR__ . '/../resources/invalid.mo';
+
+        $this->expectException(InvalidResourceException::class);
+
+        $loader->load($resource, 'en_US', 'messages');
+    }
+
+    /**
+     * @covers ::load
+     */
+    public function testCannotLoadNonExistingFile(): void
+    {
+        $loader = new MoFileLoader();
+        $resource = __DIR__ . '/../resources/non-existing.mo';
+
+        $this->expectException(NotFoundResourceException::class);
+
+        $loader->load($resource, 'en_US', 'messages');
+    }
+}

tests/resources/invalid.mo

@@ -0,0 +1,3 @@
+foobar
+test
+this is an invalid translation file

tests/resources/invalid.po

@@ -0,0 +1,3 @@
+foobar
+test
+this is an invalid translation file

tests/resources/messages.po

@@ -0,0 +1,58 @@
+msgid ""
+msgstr ""
+"Content-Type: text/plain; charset=UTF-8\n"
+"Content-Transfer-Encoding: 8bit\n"
+
+msgid "foo"
+msgstr "bar"
+
+msgid "one foo"
+msgid_plural "%count% foos"
+msgstr[0] "one bar"
+msgstr[1] "%count% bars"
+
+msgid "{0} no foos|one foo|%count% foos"
+msgstr "{0} no bars|one bar|%count% bars"
+
+msgid "missing foo plural"
+msgid_plural "missing foo plurals"
+msgstr[0] "missing bar plural"
+msgstr[1] ""
+
+msgid "missing foo singular"
+msgid_plural "missing foo singulars"
+msgstr[0] ""
+msgstr[1] "missing bar singulars"
+
+msgid "message without translation"
+msgstr ""
+
+msgid "one message without translation"
+msgid_plural "%count% messages without translations"
+msgstr[0] ""
+msgstr[1] ""
+
+msgid "{0} no messages without translations|one message without translation|%count% messages without translations"
+msgstr ""
+
+msgid "string containing || foo"
+msgstr "string containing || bar"
+
+msgid "one string containing || foo"
+msgid_plural "%count% strings containing || foos"
+msgstr[0] "one string containing || bar"
+msgstr[1] "%count% strings containing || bars"
+
+msgid "{0} no strings containing || foos|one string containing || foo|%count% strings containing || foos"
+msgstr "{0} no strings containing || bars|one string containing || bar|%count% strings containing || bars"
+
+msgid "escaped \"foo\""
+msgstr "escaped \"bar\""
+
+msgid "one escaped \"foo\""
+msgid_plural "%count% escaped \"foos\""
+msgstr[0] "one escaped \"bar\""
+msgstr[1] "%count% escaped \"bars\""
+
+msgid "{0} no escaped \"foos\"|one one escaped \"foo\"|%count% escaped \"foos\""
+msgstr "{0} no escaped \"bars\"|one one escaped \"bar\"|%count% escaped \"bars\""