Dockerを使い手軽にPHPUnitをはじめる ref: http://qiita.com/masayuki5160/items/b305d5a19f3ec632f3e3

file0.txt

$ docker pull php:5.6-apache
$ docker run -p 80:80 -v /(ホストの任意のパス)/:/var/www/html --name php56 -d php:5.6-apache
$ docker exec -ti php56 bash

file1.txt

$ apt-get update
$ apt-get install git vim
$ curl -sS https://getcomposer.org/installer | php

file2.txt

{
    "name": "phpunit",
    "description": "PHPUnit",
    "require": {
        "phpunit/phpunit": "5.7.*"
    },
    "config": {
        "bin-dir": "/usr/local/bin/"
    }
}

file3.txt

$ ./composer.pha install

file4.txt

$ php -v
PHP 5.6.31 (cli) (built: Jul 13 2017 18:38:40) 
Copyright (c) 1997-2016 The PHP Group
Zend Engine v2.6.0, Copyright (c) 1998-2016 Zend Technologies

$ phpunit --v
PHPUnit 5.7.21 by Sebastian Bergmann and contributors.

file5.php

<?php
// 2017/07/31 tadsanさんにコメント頂き修正(test/bootstrap.phpへ移した)
// require_once 'vendor/autoload.php';

class firstTest extends PHPUnit_Framework_TestCase
{
    public function testMinimumViableTest()
    {
        $this->assertTrue(false, "falseはtrueではない");
    }
}

file6.php

<?php

require_once __DIR__ . '/../vendor/autoload.php';

file6.xml

<phpunit>
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xsi:noNamespaceSchemaLocation="http://schema.phpunit.de/4.5/phpunit.xsd"
        backupGlobals="true"
        backupStaticAttributes="false"
        <!--bootstrap="/path/to/bootstrap.php"-->
        cacheTokens="false"
        colors="false"
        convertErrorsToExceptions="true"
        convertNoticesToExceptions="true"
        convertWarningsToExceptions="true"
        forceCoversAnnotation="false"
        mapTestClassNameToCoveredClassName="false"
        printerClass="PHPUnit_TextUI_ResultPrinter"
        <!--printerFile="/path/to/ResultPrinter.php"-->
        processIsolation="false"
        stopOnError="false"
        stopOnFailure="false"
        stopOnIncomplete="false"
        stopOnSkipped="false"
        stopOnRisky="false"
        testSuiteLoaderClass="PHPUnit_Runner_StandardTestSuiteLoader"
        <!--testSuiteLoaderFile="/path/to/StandardTestSuiteLoader.php"-->
        timeoutForSmallTests="1"
        timeoutForMediumTests="10"
        timeoutForLargeTests="60"
        verbose="false">
        <testsuites>
          <testsuite name="My Test Suite">
            <file>./firstTest.php</file>
          </testsuite>
        </testsuites>
</phpunit>

file7.txt

$ phpunit -c phpunit.xml
PHPUnit 5.7.21 by Sebastian Bergmann and contributors.

F                                                                   1 / 1 (100%)

Time: 348 ms, Memory: 3.00MB

There was 1 failure:

1) firstTest::testMinimumViableTest
falseはtrueではない
Failed asserting that false is true.

/var/www/html/firstTest.php:9

FAILURES!
Tests: 1, Assertions: 1, Failures: 1.

file7.xml

<phpunit>
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xsi:noNamespaceSchemaLocation="http://schema.phpunit.de/4.5/phpunit.xsd"
        backupGlobals="true"
        backupStaticAttributes="false"
        bootstrap="tests/bootstrap.php"<!-- 2017/07/31 tadsanさんにコメント頂き修正 -->
        cacheTokens="false"
        colors="false"
        convertErrorsToExceptions="true"
        convertNoticesToExceptions="true"
        convertWarningsToExceptions="true"
        forceCoversAnnotation="false"
        mapTestClassNameToCoveredClassName="false"
        printerClass="PHPUnit_TextUI_ResultPrinter"
        <!--printerFile="/path/to/ResultPrinter.php"-->
        processIsolation="false"
        stopOnError="false"
        stopOnFailure="false"
        stopOnIncomplete="false"
        stopOnSkipped="false"
        stopOnRisky="false"
        testSuiteLoaderClass="PHPUnit_Runner_StandardTestSuiteLoader"
        <!--testSuiteLoaderFile="/path/to/StandardTestSuiteLoader.php"-->
        timeoutForSmallTests="1"
        timeoutForMediumTests="10"
        timeoutForLargeTests="60"
        verbose="false">
        <testsuites>
          <testsuite name="My Test Suite">
            <file>./firstTest.php</file>
          </testsuite>
        </testsuites>
</phpunit>

file8.txt

$ phpunit -c phpunit.xml
PHPUnit 5.7.21 by Sebastian Bergmann and contributors.

F                                                                   1 / 1 (100%)

Time: 348 ms, Memory: 3.00MB

There was 1 failure:

1) firstTest::testMinimumViableTest
falseはtrueではない
Failed asserting that false is true.

/var/www/html/firstTest.php:9

FAILURES!
Tests: 1, Assertions: 1, Failures: 1.