Added PHPUnit test to prove correctness

Author: Nyholm

.travis.yml

@@ -30,6 +30,8 @@ matrix:
         - php: 7.1
         - php: 7.2
           env: COVERAGE=true TEST_COMMAND="composer test-ci"  DEPENDENCIES="henrikbjorn/phpspec-code-coverage:^1.0"
+        - php: 7.2
+          env: TEST_COMMAND="./vendor/bin/phpunit" DEPENDENCIES="phpunit/phpunit:^7.5 nyholm/psr7:^1.0"
 
           # Test LTS versions
         - php: 7.1

phpunit.xml.dist

@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="UTF-8"?>
+
+<phpunit bootstrap="./vendor/autoload.php"
+         colors="true"
+         convertErrorsToExceptions="true"
+         convertNoticesToExceptions="true"
+         convertWarningsToExceptions="true">
+    <php>
+        <env name="SHELL_VERBOSITY" value="-1" />
+    </php>
+
+    <testsuites>
+        <testsuite name="HTTPlug unit tests">
+            <directory suffix="Test.php">./tests</directory>
+        </testsuite>
+    </testsuites>
+</phpunit>

tests/Plugin/AddPathPluginTest.php

@@ -0,0 +1,81 @@
+<?php
+
+namespace tests\Http\Client\Common\Plugin;
+
+use Http\Client\Common\Plugin;
+use Http\Client\Common\Plugin\AddPathPlugin;
+use Nyholm\Psr7\Request;
+use Nyholm\Psr7\Uri;
+use PHPUnit\Framework\TestCase;
+use Psr\Http\Message\RequestInterface;
+
+class AddPathPluginTest extends TestCase
+{
+    /**
+     * @var Plugin
+     */
+    private $plugin;
+
+    /**
+     * @var callable empty
+     */
+    private $callable;
+
+    protected function setUp()
+    {
+        $this->callable = function () {};
+        $this->plugin = new AddPathPlugin(new Uri('/api'));
+    }
+
+    public function testRewriteSameObject()
+    {
+        $request = new Request('GET', 'https://example.com/foo');
+        $this->plugin->handleRequest($request, function (RequestInterface $request) {
+            $this->assertEquals('https://example.com/api/foo', $request->getUri()->__toString());
+        }, $this->callable);
+
+        // Make a second call with the same $request object
+        $this->plugin->handleRequest($request, function (RequestInterface $request) {
+            $this->assertEquals('https://example.com/api/foo', $request->getUri()->__toString());
+        }, $this->callable);
+    }
+
+    public function testRewriteOnRestart()
+    {
+        $request = new Request('GET', 'https://example.com/foo');
+        $this->plugin->handleRequest($request, function (RequestInterface $request) {
+            $this->assertEquals('https://example.com/api/foo', $request->getUri()->__toString());
+
+            // Run the plugin again with the modified request
+            $this->plugin->handleRequest($request, function (RequestInterface $request) {
+                $this->assertEquals('https://example.com/api/foo', $request->getUri()->__toString());
+            }, $this->callable);
+        }, $this->callable);
+    }
+
+    public function testRewriteWithDifferentUrl()
+    {
+        $request = new Request('GET', 'https://example.com/foo');
+        $this->plugin->handleRequest($request, function (RequestInterface $request) {
+            $this->assertEquals('https://example.com/api/foo', $request->getUri()->__toString());
+        }, $this->callable);
+
+        $request = new Request('GET', 'https://example.com/bar');
+        $this->plugin->handleRequest($request, function (RequestInterface $request) {
+            $this->assertEquals('https://example.com/api/bar', $request->getUri()->__toString());
+        }, $this->callable);
+    }
+
+    public function testRewriteWithDifferentUrlWhenSecondUrlIncludesAddedPath()
+    {
+        $request = new Request('GET', 'https://example.com/foo');
+        $this->plugin->handleRequest($request, function (RequestInterface $request) {
+            $this->assertEquals('https://example.com/api/foo', $request->getUri()->__toString());
+        }, $this->callable);
+
+        $request = new Request('GET', 'https://example.com/api/foo');
+        $this->plugin->handleRequest($request, function (RequestInterface $request) {
+            $this->assertEquals('https://example.com/api/foo', $request->getUri()->__toString());
+        }, $this->callable);
+    }
+}