Run dockunit (but could do with phpunit or any other command) if any php files have changed and are about to be pushed. Rename to `pre-push` and put in the `.git/hooks/` directory.

git-pre-push.php

#!/usr/bin/php
<?php

$lines = file_get_contents( 'php://stdin', 'r' );
if ( empty( $lines ) ) {
	exit( 0 );
}

$lines = explode( "\n", $lines );
$lines = explode( ' ', $lines[0] );

exec( 'git diff --name-only '. $lines[1] .' '. $lines[3], $files );

$do_tests = false;
if ( ! empty( $files ) ) {
	foreach ( $files as $file ) {
		$parts = explode( '.', $file );
		$ext = end( $parts );
		if ( 'php' == $ext ) {
			$do_tests = true;
		}
	}
}

if ( ! $do_tests ) {
	exit( 0 );
}

echo "Run Dockunit\n";

$projectName = basename( getcwd() );

exec( 'dockunit', $output, $returnCode );

if ( 0 !== $returnCode ) {
	$minimalTestSummary = array_pop( $output );
	printf( "Test suite for %s failed: ", $projectName );
	printf( "(%s) %s%2\$s", $minimalTestSummary, PHP_EOL );
	printf( "ABORTING PUSH!\n" );
	exit( 1 );
}

printf( "All tests for %s passed.%s%2\$s", $projectName, PHP_EOL );
exit( 0 );