Improve test suite by adding test instructions and adding PHPUnit to require-dev

.travis.yml

@@ -1,17 +1,29 @@
 language: php
 
 php:
-  - 5.3
+# - 5.3 # requires old distro, see below
   - 5.4
   - 5.5
   - 5.6
-  - 7
-  - hhvm
+  - 7.0
+  - 7.1
+  - 7.2
+  - hhvm # ignore errors, see below
+
+# lock distro so future defaults will not break the build
+dist: trusty
+
+matrix:
+  include:
+    - php: 5.3
+      dist: precise
+  allow_failures:
+    - php: hhvm
 
 sudo: false
 
 install:
   - composer install --no-interaction
 
 script:
-  - phpunit --coverage-text
+  - vendor/bin/phpunit --coverage-text

README.md

@@ -19,6 +19,7 @@ But many other tools may need similar parsing during their runtime.
   * [split()](#split)
   * [UnclosedQuotesException](#unclosedquotesexception)
 * [Install](#install)
+* [Tests](#tests)
 * [License](#license)
 * [More](#more)
 
@@ -67,7 +68,7 @@ Alternatively, you can also refer to them with their fully-qualified name:
 
 ```php
 \Clue\Arguments\split(…);
-``` 
+```
 
 #### split()
 
@@ -230,6 +231,26 @@ $ composer require clue/arguments:^2.0
 
 See also the [CHANGELOG](CHANGELOG.md) for details about version upgrades.
 
+This project aims to run on any platform and thus does not require any PHP
+extensions and supports running on legacy PHP 5.3 through current PHP 7+ and
+HHVM.
+It's *highly recommended to use PHP 7+* for this project.
+
+## Tests
+
+To run the test suite, you first need to clone this repo and then install all
+dependencies [through Composer](http://getcomposer.org):
+
+```bash
+$ composer install
+```
+
+To run the test suite, go to the project root and run:
+
+```bash
+$ php vendor/bin/phpunit
+```
+
 ## License
 
 MIT

composer.json

@@ -13,6 +13,9 @@
     "require": {
         "php": ">=5.3"
     },
+    "require-dev": {
+        "phpunit/phpunit": "^7.0 || ^6.0 || ^5.7 || ^4.8.35"
+    },
     "autoload": {
         "files": [ "src/functions.php" ],
         "psr-4": { "Clue\\Arguments\\": "src/" }

tests/SplitTest.php

@@ -2,7 +2,7 @@
 
 use Clue\Arguments;
 
-class SplitTest extends PHPUnit_Framework_TestCase
+class SplitTest extends PHPUnit\Framework\TestCase
 {
     public function testEmptyString()
     {

tests/UnclosedQuotesExceptionTest.php

@@ -2,7 +2,7 @@
 
 use Clue\Arguments\UnclosedQuotesException;
 
-class UnclosedQuotesExceptionTest extends PHPUnit_Framework_TestCase
+class UnclosedQuotesExceptionTest extends PHPUnit\Framework\TestCase
 {
     public function testCtorWithOnlyQuotesAppliesMessage()
     {