fixed shim:

Author: DavertMik

src/shim.php

@@ -39,14 +39,14 @@ class_alias('PHPUnit_Util_Test', 'PHPUnit\Util\Test');
         class_alias('PHPUnit_Util_TestDox_ResultPrinter', 'PHPUnit\Util\TestDox\ResultPrinter');
 
     }
-    if (!class_exists('\PHPUnit\Util\Log\JSON') || !class_exists('\PHPUnit\Util\Log\TAP')) {
+    if (!class_exists('PHPUnit\Util\Log\JSON') || !class_exists('PHPUnit\Util\Log\TAP')) {
         if (class_exists('PHPUnit\Util\Printer')) {
             require_once __DIR__ . '/phpunit5-loggers.php'; // TAP and JSON loggers were removed in PHPUnit 6
         }
     }
 
     // phpunit codecoverage updates
-    if (!class_exists('SebastianBergmann\CodeCoverage\CodeCoverage') && class_exists('PHP_CodeCoverage')) {
+    if (class_exists('PHP_CodeCoverage' && !class_exists('SebastianBergmann\CodeCoverage\CodeCoverage'))) {
         class_alias('PHP_CodeCoverage', 'SebastianBergmann\CodeCoverage\CodeCoverage');
         class_alias('PHP_CodeCoverage_Report_Text', 'SebastianBergmann\CodeCoverage\Report\Text');
         class_alias('PHP_CodeCoverage_Report_PHP', 'SebastianBergmann\CodeCoverage\Report\PHP');