Fix UID test and make debugging easier

This should fix the test and make the test failures (if any)
more informative.

The issue was that it was trying to extract a 46-bit segment
(the timestamp).  But because the whole thing wasn't 0-padded first,
the timestamp might be shorter.  So it would extract part of the next
segment too.  That meant it was testing a 46-bit segment with no
guaranteed properties, with arbitrary results.

Bug: T131549
Change-Id: I11c9e86951cc1d6b186710cda6e42ee58c920db8

diff --git a/tests/phpunit/includes/utils/UIDGeneratorTest.php b/tests/phpunit/includes/utils/UIDGeneratorTest.php
index d746ea1..60d4e99 100644 (file)
--- a/tests/phpunit/includes/utils/UIDGeneratorTest.php
+++ b/tests/phpunit/includes/utils/UIDGeneratorTest.php
@@ -9,9 +9,8 @@ class UIDGeneratorTest extends PHPUnit_Framework_TestCase {
        }
 
        /**
-        * Flaky test (T131549).
+        * Test that generated UIDs have the expected properties
         *
-        * @group Broken
         * @dataProvider provider_testTimestampedUID
         * @covers UIDGenerator::newTimestampedUID128
         * @covers UIDGenerator::newTimestampedUID88
@@ -34,19 +33,29 @@ class UIDGeneratorTest extends PHPUnit_Framework_TestCase {
                $this->assertSame( array_unique( $ids ), $ids, "All generated IDs are unique." );
 
                foreach ( $ids as $id ) {
-                       $id_bin = Wikimedia\base_convert( $id, 10, 2 );
-                       $lastId_bin = Wikimedia\base_convert( $lastId, 10, 2 );
+                       // Convert string to binary and pad to full length so we can
+                       // extract segments
+                       $id_bin = Wikimedia\base_convert( $id, 10, 2, $bits );
+                       $lastId_bin = Wikimedia\base_convert( $lastId, 10, 2, $bits );
+
+                       $timestamp_bin = substr( $id_bin, 0, $tbits );
+                       $last_timestamp_bin = substr( $lastId_bin, 0, $tbits );
 
                        $this->assertGreaterThanOrEqual(
-                               substr( $lastId_bin, 0, $tbits ),
-                               substr( $id_bin, 0, $tbits ),
-                               "New ID timestamp ($id_bin) >= prior one ($lastId_bin)." );
+                               $last_timestamp_bin,
+                               $timestamp_bin,
+                               "timestamp ($timestamp_bin) of current ID ($id_bin) >= timestamp ($last_timestamp_bin) " .
+                                 "of prior one ($lastId_bin)" );
+
+                       $hostbits_bin = substr( $id_bin, -$hostbits );
+                       $last_hostbits_bin = substr( $lastId_bin, -$hostbits );
 
                        if ( $hostbits ) {
                                $this->assertEquals(
-                                       substr( $id_bin, -$hostbits ),
-                                       substr( $lastId_bin, -$hostbits ),
-                                       "Host ID of ($id_bin) is same as prior one ($lastId_bin)." );
+                                       $hostbits_bin,
+                                       $last_hostbits_bin,
+                                       "Host ID ($hostbits_bin) of current ID ($id_bin) is same as host ID ($last_hostbits_bin) " .
+                                         "of prior one ($lastId_bin)." );
                        }
 
                        $lastId = $id;