[4.x] Support for validation Rule objects (#9332)

src/Fields/ClassRuleParser.php

@@ -0,0 +1,44 @@
+<?php
+
+namespace Statamic\Fields;
+
+use Statamic\Support\Str;
+
+class ClassRuleParser
+{
+    public function parse(string $rule): array
+    {
+        $rule = Str::substr($rule, 4);
+
+        if (! str_contains($rule, '(')) {
+            return [$rule, []];
+        }
+
+        $class = Str::before($rule, '(');
+
+        $arguments = Str::of($rule)
+            ->between('(', ')')
+            ->explode(',')
+            ->mapWithKeys(function ($arg, $key) {
+                $arg = trim($arg);
+
+                if (preg_match('/^[a-zA-Z]+: ?/', $arg)) {
+                    [$key, $arg] = explode(':', $arg, 2);
+                    $key = trim($key);
+                    $arg = trim($arg);
+                }
+
+                if (is_numeric($arg)) {
+                    return [$key => str_contains($arg, '.') ? (float) $arg : (int) $arg];
+                } elseif (Str::startsWith($arg, '"') && Str::endsWith($arg, '"')) {
+                    return [$key => (string) Str::of($arg)->trim('"')->replace('\\"', '"')];
+                } elseif (Str::startsWith($arg, "'") && Str::endsWith($arg, "'")) {
+                    return [$key => (string) Str::of($arg)->trim("'")->replace("\\'", "'")];
+                }
+
+                return [$key => $arg];
+            });
+
+        return [$class, $arguments->all()];
+    }
+}

src/Fields/Validator.php

@@ -124,6 +124,12 @@ public function attributes()
 
     private function parse($rule)
     {
+        if (is_string($rule) && Str::startsWith($rule, 'new ')) {
+            [$class, $arguments] = (new ClassRuleParser)->parse($rule);
+
+            return new $class(...$arguments);
+        }
+
         if (! is_string($rule) ||
             ! Str::contains($rule, '{') ||
             Str::startsWith($rule, 'regex:') ||

tests/Fields/ClassRuleParserTest.php

@@ -0,0 +1,71 @@
+<?php
+
+namespace Tests\Fields;
+
+use Statamic\Fields\ClassRuleParser;
+use Tests\TestCase;
+
+class ClassRuleParserTest extends TestCase
+{
+    /**
+     * @test
+     *
+     * @dataProvider classRuleProvider
+     */
+    public function it_parses_class_rules($input, $expected)
+    {
+        $output = (new ClassRuleParser)->parse($input);
+
+        $this->assertSame($expected, $output);
+    }
+
+    public static function classRuleProvider()
+    {
+        return [
+            'just class' => [
+                'new App\MyRule',
+                ['App\MyRule', []],
+            ],
+            'single quoted string' => [
+                "new App\MyRule('foo')",
+                ['App\MyRule', ['foo']],
+            ],
+            'double quoted string' => [
+                'new App\MyRule("foo")',
+                ['App\MyRule', ['foo']],
+            ],
+            'multiple arguments' => [
+                "new App\MyRule('foo', 123, 'bar')",
+                ['App\MyRule', ['foo', 123, 'bar']],
+            ],
+            'quote in a single quoted string' => [
+                "new App\MyRule('it\'s a me mario')",
+                ['App\MyRule', ["it's a me mario"]],
+            ],
+            'double quote in a double quoted string' => [
+                'new App\MyRule("stop trying to make \"fetch\" happen")',
+                ['App\MyRule', ['stop trying to make "fetch" happen']],
+            ],
+            'only named arguments' => [
+                'new App\MyRule(a: "foo", b: 123)',
+                ['App\MyRule', ['a' => 'foo', 'b' => 123]],
+            ],
+            'only named arguments with no spaces' => [
+                'new App\MyRule(a:"foo", b:123)',
+                ['App\MyRule', ['a' => 'foo', 'b' => 123]],
+            ],
+            'some named arguments' => [
+                'new App\MyRule("foo", c: 123)',
+                ['App\MyRule', ['foo', 'c' => 123]],
+            ],
+            'non-named argument with colon' => [
+                'new App\MyRule("foo:bar")',
+                ['App\MyRule', ['foo:bar']],
+            ],
+            'named argument with colon' => [
+                'new App\MyRule(a: "foo:bar")',
+                ['App\MyRule', ['a' => 'foo:bar']],
+            ],
+        ];
+    }
+}