Skip tests when 'git' command is not available

This change is intended to be a quick-fix to allow the test suite to pass. A
later enhancement would be to move this check to happen at runtime so that if a
user attempts to use one of these affected filters, a suitable error message
and exit code can be used. When that happens, the tests will need to be
reworked to cover that functionality.

Author: fredden

tests/Core/Filters/GitModifiedTest.php

@@ -9,6 +9,7 @@
 
 namespace PHP_CodeSniffer\Tests\Core\Filters;
 
+use PHP_CodeSniffer\Config;
 use PHP_CodeSniffer\Filters\GitModified;
 use PHP_CodeSniffer\Tests\Core\Filters\AbstractFilterTestCase;
 use RecursiveArrayIterator;
@@ -219,6 +220,10 @@ public function testExecAlwaysReturnsArray($cmd, $expected)
             $this->markTestSkipped('Not a git repository');
         }
 
+        if (Config::getExecutablePath('git') === null) {
+            $this->markTestSkipped('git command not available');
+        }
+
         $fakeDI = new RecursiveArrayIterator(self::getFakeFileList());
         $filter = new GitModified($fakeDI, '/', self::$config, self::$ruleset);
 

tests/Core/Filters/GitStagedTest.php

@@ -9,6 +9,7 @@
 
 namespace PHP_CodeSniffer\Tests\Core\Filters;
 
+use PHP_CodeSniffer\Config;
 use PHP_CodeSniffer\Filters\GitStaged;
 use PHP_CodeSniffer\Tests\Core\Filters\AbstractFilterTestCase;
 use RecursiveArrayIterator;
@@ -219,6 +220,10 @@ public function testExecAlwaysReturnsArray($cmd, $expected)
             $this->markTestSkipped('Not a git repository');
         }
 
+        if (Config::getExecutablePath('git') === null) {
+            $this->markTestSkipped('git command not available');
+        }
+
         $fakeDI = new RecursiveArrayIterator(self::getFakeFileList());
         $filter = new GitStaged($fakeDI, '/', self::$config, self::$ruleset);