The Great Parser JS to PHP port of 2020!*

* Not to be confused with the Parsing Team's
"Great Parser JS to PHP port of 2019"

Gasp as OR hacks are changed to null coalescing operators.
Applaud as variable declarations are dropped.
Cheer as parameters and return values are type-hinted.
Shudder as DomNodeLists have no indexOf method.

Moving discussion parsing to the server should allow
us to implement much cleaner APIs for commenting.

Bug: T252252
Co-authored-by: Ed Sanders <esanders@wikimedia.org>
Change-Id: Ic1438d516e223db462cb227f6668e856672f538c

.phpcs.xml

@@ -1,6 +1,8 @@
 <?xml version="1.0"?>
 <ruleset>
-	<rule ref="./vendor/mediawiki/mediawiki-codesniffer/MediaWiki" />
+	<rule ref="./vendor/mediawiki/mediawiki-codesniffer/MediaWiki">
+		<exclude name="MediaWiki.ControlStructures.AssignmentInControlStructures.AssignmentInControlStructures" />
+	</rule>
 	<file>.</file>
 	<arg name="extensions" value="php,php5,inc" />
 	<arg name="encoding" value="UTF-8" />

extension.json

@@ -225,6 +225,7 @@
 		]
 	},
 	"AutoloadClasses": {
+		"DiscussionToolsCommentParser": "includes/DiscussionToolsCommentParser.php",
 		"DiscussionToolsData": "includes/DiscussionToolsData.php",
 		"DiscussionToolsHooks": "includes/DiscussionToolsHooks.php"
 	},

tests/phpunit/DiscussionToolsCommentParserTest.php

@@ -0,0 +1,124 @@
+<?php
+
+use Wikimedia\TestingAccessWrapper;
+
+/**
+ * @coversDefaultClass DiscussionToolsCommentParser
+ */
+class DiscussionToolsCommentParserTest extends MediaWikiTestCase {
+
+	private static function getJson( $relativePath ) {
+		$json = json_decode(
+			// TODO: Move cases out of /qunit
+			file_get_contents( __DIR__ . '/../qunit/' . $relativePath ),
+			true
+		);
+		return $json;
+	}
+
+	/**
+	 * @dataProvider provideTimestampRegexps
+	 * @covers ::getTimestampRegexp
+	 */
+	public function testGetTimestampRegexp( $format, $expected, $message ) {
+		$parser = TestingAccessWrapper::newFromObject(
+			DiscussionToolsCommentParser::newFromGlobalState()
+		);
+
+		// HACK: Fix differences between JS & PHP regexes
+		// TODO: We may just have to have two version in the test data
+		$expected = preg_replace( '/\\\\u([0-9A-F]+)/', '\\\\x{$1}', $expected );
+		$expected = str_replace( ':', '\:', $expected );
+		$expected = '/' . $expected . '/u';
+
+		$result = $parser->getTimestampRegexp( $format, '\\d', [ 'UTC' => 'UTC' ] );
+		self::assertSame( $expected, $result, $message );
+	}
+
+	public function provideTimestampRegexps() {
+		return self::getJson( './cases/timestamp-regex.json' );
+	}
+
+	/**
+	 * @dataProvider provideTimestampParser
+	 * @covers ::getTimestampParser
+	 */
+	public function testGetTimestampParser( $format, $data, $expected, $message ) {
+		$parser = TestingAccessWrapper::newFromObject(
+			DiscussionToolsCommentParser::newFromGlobalState()
+		);
+
+		$expected = new DateTimeImmutable( $expected );
+
+		$tsParser = $parser->getTimestampParser( $format, null, 'UTC', [ 'UTC' => 'UTC' ] );
+		self::assertEquals( $expected, $tsParser( $data ), $message );
+	}
+
+	public function provideTimestampParser() {
+		return self::getJson( './cases/timestamp-parser.json' );
+	}
+
+	/**
+	 * @dataProvider provideTimestampParserDST
+	 * @covers ::getTimestampParser
+	 */
+	public function testGetTimestampParserDST(
+		$sample, $expected, $expectedUtc, $format, $timezone, $timezoneAbbrs, $message
+	) {
+		$parser = TestingAccessWrapper::newFromObject(
+			DiscussionToolsCommentParser::newFromGlobalState()
+		);
+
+		$regexp = $parser->getTimestampRegexp( $format, '\\d', $timezoneAbbrs );
+		$tsParser = $parser->getTimestampParser( $format, null, $timezone, $timezoneAbbrs );
+
+		$expected = new DateTimeImmutable( $expected );
+		$expectedUtc = new DateTimeImmutable( $expectedUtc );
+
+		preg_match( $regexp, $sample, $match, PREG_OFFSET_CAPTURE );
+		$date = $tsParser( $match );
+
+		self::assertEquals( $expected, $date, $message );
+		self::assertEquals( $expectedUtc, $date, $message );
+	}
+
+	public function provideTimestampParserDST() {
+		return self::getJson( './cases/timestamp-parser-dst.json' );
+	}
+
+	/**
+	 * @dataProvider provideAuthors
+	 * @covers ::getAuthors
+	 */
+	public function testGetAuthors( $thread, $expected ) {
+		$parser = DiscussionToolsCommentParser::newFromGlobalState();
+
+		self::assertEquals( $expected, $parser->getAuthors( $thread ) );
+	}
+
+	public function provideAuthors() {
+		return [
+			[
+				'thread' => (object)[
+					'replies' => [
+						(object)[
+							'author' => 'Eve',
+							'replies' => []
+						],
+						(object)[
+							'author' => 'Bob',
+							'replies' => [
+								(object)[
+									'author' => 'Alice',
+									'replies' => []
+								]
+							]
+						]
+
+					]
+				],
+				'expected' => [ 'Alice', 'Bob', 'Eve' ]
+			]
+		];
+	}
+}