From f5fdda0ba10637a6d3b522b183c679fc8215cb53 Mon Sep 17 00:00:00 2001
From: Moritz Schubotz <wiki@physikerwelt.de>
Date: Wed, 17 Aug 2016 19:41:04 +0200
Subject: [PATCH] Improve error reporting

Display error message in the UI,
if the check command passes,
but the mml/svg/complete endpoints returns an valid json error.

Bug: T143225
Change-Id: I50776926e42f75a2c1e30fc9afe08baae3fcdbd1
---
 MathRestbaseInterface.php           | 20 ++++++++++++++++-
 tests/MathRestBaseInterfaceTest.php | 34 +++++++++++++++++++++++++++++
 2 files changed, 53 insertions(+), 1 deletion(-)

diff --git a/MathRestbaseInterface.php b/MathRestbaseInterface.php
index f223b0a..a2d8470 100644
--- a/MathRestbaseInterface.php
+++ b/MathRestbaseInterface.php
@@ -428,6 +428,24 @@ class MathRestbaseInterface {
 			'math_type' => $type,
 			'tex' => $this->tex
 		] );
-		throw new MWException( "Cannot get $type. Server problem." );
+		self::throwContentError( $type, $response['body'] );
+	}
+
+	/**
+	 * @param $type
+	 * @param $body
+	 * @throws MWException
+	 */
+	public static function throwContentError( $type, $body ) {
+		$detail = 'Server problem.';
+		$json = json_decode( $body );
+		if ( isset( $json->detail ) ) {
+			if ( is_array( $json->detail ) ){
+				$detail = $json->detail[0];
+			} elseif ( is_string( $json->detail ) ) {
+				$detail = $json->detail;
+			}
+		}
+		throw new MWException( "Cannot get $type. $detail" );
 	}
 }
diff --git a/tests/MathRestBaseInterfaceTest.php b/tests/MathRestBaseInterfaceTest.php
index af21836..9ab6f39 100644
--- a/tests/MathRestBaseInterfaceTest.php
+++ b/tests/MathRestBaseInterfaceTest.php
@@ -85,4 +85,38 @@ class MathRestbaseInterfaceTest extends MediaWikiTestCase {
 		$rbi->getFullSvgUrl();
 	}
 
+	/**
+	 * Incorporate the "details" in the error message, if the check requests passes, but the
+	 * mml/svg/complete endpoints returns an error
+	 * @expectedException MWException
+	 * @expectedExceptionMessage Cannot get mml. TeX parse error: Missing close brace
+	 */
+	public function testLateError() {
+		// @codingStandardsIgnoreStart
+		$input = '{"type":"https://mediawiki.org/wiki/HyperSwitch/errors/bad_request","title":"Bad Request","method":"POST","detail":["TeX parse error: Missing close brace"],"uri":"/complete"}';
+		// @codingStandardsIgnoreEnd
+		MathRestbaseInterface::throwContentError( 'mml', $input );
+	}
+
+	/**
+	 * Incorporate the "details" in the error message, if the check requests passes, but the
+	 * mml/svg/complete endpoints returns an error
+	 * @expectedException MWException
+	 * @expectedExceptionMessage Cannot get mml. TeX parse error: Missing close brace
+	 */
+	public function testLateErrorString() {
+		// @codingStandardsIgnoreStart
+		$input = '{"type":"https://mediawiki.org/wiki/HyperSwitch/errors/bad_request","title":"Bad Request","method":"POST","detail": "TeX parse error: Missing close brace","uri":"/complete"}';
+		// @codingStandardsIgnoreEnd
+		MathRestbaseInterface::throwContentError( 'mml', $input );
+	}
+
+	/**
+	 * @expectedException MWException
+	 * @expectedExceptionMessage Cannot get mml. Server problem.
+	 */
+	public function testLateErrorNoDetail() {
+		$input = '';
+		MathRestbaseInterface::throwContentError( 'mml', $input );
+	}
 }