Add Pest/PHPUnit and unit tests

Added:
- pestphp/pest `^1.22`
- PHP 7.4 for tests

Author: mcaskill

.gitattributes

@@ -11,6 +11,7 @@
 /.gitattributes    export-ignore
 /.gitignore        export-ignore
 /composer.lock     export-ignore
+/phpunit.xml.dist  export-ignore
 
 # Avoid merging lock files
 composer.lock -diff

.gitignore

@@ -2,4 +2,6 @@
 /vendor/
 
 # Files
+/.phpunit.result.cache
 /composer.lock
+/phpunit.xml

composer.json

@@ -18,7 +18,24 @@
         "php": ">=5.4.0",
         "ext-json": "*"
     },
+    "require-dev": {
+        "php": ">=7.4.0",
+        "pestphp/pest": "^1.22"
+    },
     "autoload": {
         "files": [ "Function.HTML-Build-Attributes.php" ]
+    },
+    "config": {
+        "allow-plugins": {
+            "pestphp/pest-plugin": true
+        }
+    },
+    "scripts": {
+        "test": [
+            "@test:pest"
+        ],
+        "test:pest": [
+            "pest"
+        ]
     }
 }

phpunit.xml.dist

@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<phpunit
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:noNamespaceSchemaLocation="vendor/phpunit/phpunit/phpunit.xsd"
+    bootstrap="vendor/autoload.php"
+    colors="true"
+>
+    <testsuites>
+        <testsuite name="Test Suite">
+            <directory suffix="Test.php">./tests</directory>
+        </testsuite>
+    </testsuites>
+    <coverage processUncoveredFiles="true">
+        <include>
+            <file>Function.HTML-Build-Attributes.php</file>
+        </include>
+    </coverage>
+</phpunit>

tests/Test.php

@@ -0,0 +1,78 @@
+<?php
+
+/**
+ * @param mixed $input The variable to be passed to the function.
+ */
+it('returns an empty string', function ($input) {
+    $output = html_build_attributes($input);
+
+    expect($output)->toBeString()->toBeEmpty();
+})->with([
+    'scalar',
+    (new stdClass()),
+    (new ArrayIterator()),
+    [
+        [
+            ''        => 'empty',
+            '   '     => 'whitespace',
+            'null'    => null,
+            'false'   => false,
+            'array'   => [],
+        ],
+    ],
+]);
+
+$inputBuildsExpectedHtml = function ($html, $input) : void {
+    $output = html_build_attributes($input);
+
+    expect($output)->toBe($html);
+};
+
+/**
+ * @param string $html  The expected return value.
+ * @param mixed  $input The variable to be passed to the function.
+ */
+it('generates HTML attributes', $inputBuildsExpectedHtml)->with([
+    [
+        'id="foobar" required class="foo baz 0 qux"',
+        [
+            'id'       => function () {
+                return 'foobar';
+            },
+            'required' => true,
+            'class'    => [ 'foo', null, '', '   ', '  baz ', 0, true, false, 'qux' ],
+        ],
+    ],
+    [
+        'data-arr="one two three"',
+        [
+            'data-arr' => new class {
+                public function toArray() : array
+                {
+                    return [ 'one', 'two', 'three' ];
+                }
+            },
+        ],
+    ],
+    [
+        'data-str="bazqux"',
+        [
+            'data-str' => new class {
+                public function __toString() : string
+                {
+                    return 'bazqux';
+                }
+            },
+        ],
+    ],
+    [
+        'data-obj="{&quot;a&quot;:1,&quot;b&quot;:2,&quot;c&quot;:3}"',
+        [
+            'data-obj' => new class {
+                public $a = 1;
+                public $b = 2;
+                public $c = 3;
+            },
+        ],
+    ],
+]);