feat(console): accept BackedEnum as command arguments

src/Tempest/Console/src/Actions/RenderConsoleCommand.php

@@ -32,6 +32,10 @@ public function __invoke(ConsoleCommand $consoleCommand): void
 
     private function renderArgument(ConsoleArgumentDefinition $argument): string
     {
+        if ($argument->isBackedEnum()) {
+            return $this->renderEnumArgument($argument);
+        }
+
         $name = str($argument->name)
             ->prepend('<em>')
             ->append('</em>');
@@ -53,4 +57,24 @@ private function renderArgument(ConsoleArgumentDefinition $argument): string
             default => "[{$asString}={$argument->default}]"
         };
     }
+
+    private function renderEnumArgument(ConsoleArgumentDefinition $argument): string
+    {
+        $enum = $argument->type;
+        $values = $enum::cases();
+        $parts = [];
+
+        foreach ($values as $value) {
+            $parts[] = $value->value;
+        }
+
+        $partsAsString = ' {<em>' . implode('|', $parts) . '</em>}';
+        $line = "<em>{$argument->name}</em>";
+
+        if ($argument->hasDefault) {
+            return "[{$line}={$argument->default->value}{$partsAsString}]";
+        }
+
+        return "<{$line}{$partsAsString}>";
+    }
 }

src/Tempest/Console/src/Exceptions/InvalidEnumArgument.php

@@ -0,0 +1,40 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Tempest\Console\Exceptions;
+
+use function array_map;
+use BackedEnum;
+use function gettype;
+use function implode;
+use function is_string;
+use Tempest\Console\Console;
+
+final class InvalidEnumArgument extends ConsoleException
+{
+    /**
+     * @param class-string<BackedEnum> $argumentType
+     */
+    public function __construct(
+        private string $argumentName,
+        private string $argumentType,
+        private mixed $value,
+    ) {
+    }
+
+    public function render(Console $console): void
+    {
+        if (is_string($this->value) || is_numeric($this->value)) {
+            $value = "`{$this->value}`";
+        } else {
+            $value = 'of type `' . gettype($this->value) . '`';
+        }
+
+        $cases = array_map(
+            callback: fn (BackedEnum $case) => $case->value,
+            array: $this->argumentType::cases(),
+        );
+        $console->error("Invalid argument {$value} for `{$this->argumentName}` argument, valid values are: " . implode(', ', $cases));
+    }
+}

src/Tempest/Console/src/Input/ConsoleArgumentBag.php

@@ -4,6 +4,8 @@
 
 namespace Tempest\Console\Input;
 
+use Tempest\Console\Exceptions\InvalidEnumArgument;
+
 final class ConsoleArgumentBag
 {
     /** @var ConsoleInputArgument[] */
@@ -93,7 +95,7 @@ public function findFor(ConsoleArgumentDefinition $argumentDefinition): ?Console
     {
         foreach ($this->arguments as $argument) {
             if ($argumentDefinition->matchesArgument($argument)) {
-                return $argument;
+                return $this->resolveArgumentValue($argumentDefinition, $argument);
             }
         }
 
@@ -108,6 +110,27 @@ public function findFor(ConsoleArgumentDefinition $argumentDefinition): ?Console
         return null;
     }
 
+    private function resolveArgumentValue(
+        ConsoleArgumentDefinition $argumentDefinition,
+        ConsoleInputArgument $argument,
+    ): ConsoleInputArgument {
+        if ($argumentDefinition->isBackedEnum()) {
+            $resolved = $argumentDefinition->type::tryFrom($argument->value);
+
+            if ($resolved === null) {
+                throw new InvalidEnumArgument(
+                    $argumentDefinition->name,
+                    $argumentDefinition->type,
+                    $argument->value,
+                );
+            }
+
+            $argument->value = $resolved;
+        }
+
+        return $argument;
+    }
+
     public function findArrayFor(ConsoleArgumentDefinition $argumentDefinition): ?ConsoleInputArgument
     {
         $values = [];

src/Tempest/Console/src/Input/ConsoleArgumentDefinition.php

@@ -4,6 +4,7 @@
 
 namespace Tempest\Console\Input;
 
+use BackedEnum;
 use Tempest\Console\ConsoleArgument;
 use Tempest\Reflection\ParameterReflector;
 use function Tempest\Support\str;
@@ -70,4 +71,9 @@ private static function normalizeName(string $name, bool $boolean): string
 
         return $normalizedName->toString();
     }
+
+    public function isBackedEnum(): bool
+    {
+        return is_subclass_of($this->type, BackedEnum::class);
+    }
 }

tests/Integration/Console/ConsoleArgumentBagTest.php

@@ -5,8 +5,10 @@
 namespace Tests\Tempest\Integration\Console;
 
 use PHPUnit\Framework\Attributes\TestWith;
+use Tempest\Console\Exceptions\InvalidEnumArgument;
 use Tempest\Console\Input\ConsoleArgumentBag;
 use Tempest\Console\Input\ConsoleArgumentDefinition;
+use Tests\Tempest\Integration\Console\Fixtures\TestStringEnum;
 use Tests\Tempest\Integration\FrameworkIntegrationTestCase;
 
 /**
@@ -138,6 +140,49 @@ public function test_negative_input(string $name, bool $expected): void
         $this->assertSame($expected, $bag->findFor($definition)->value);
     }
 
+    public function test_backed_enum_input(): void
+    {
+        $argv = [
+            'tempest',
+            'test',
+            '--type=a',
+        ];
+
+        $bag = new ConsoleArgumentBag($argv);
+
+        $definition = new ConsoleArgumentDefinition(
+            name: 'type',
+            type: TestStringEnum::class,
+            default: null,
+            hasDefault: false,
+            position: 0,
+        );
+
+        $this->assertSame(TestStringEnum::A, $bag->findFor($definition)->value);
+    }
+
+    public function test_invalid_backed_enum_input(): void
+    {
+        $argv = [
+            'tempest',
+            'test',
+            '--type=invalid',
+        ];
+
+        $bag = new ConsoleArgumentBag($argv);
+
+        $definition = new ConsoleArgumentDefinition(
+            name: 'type',
+            type: TestStringEnum::class,
+            default: null,
+            hasDefault: false,
+            position: 0,
+        );
+
+        $this->expectException(InvalidEnumArgument::class);
+        $bag->findFor($definition);
+    }
+
     public function test_name_mapping(): void
     {
         $this->console

tests/Integration/Console/Fixtures/MyConsole.php

@@ -14,6 +14,8 @@ final class MyConsole
     )]
     public function handle(
         string $path,
+        TestStringEnum $type,
+        TestStringEnum $fallback = TestStringEnum::A,
         int    $times = 1,
         bool   $force = false,
     ): void {

tests/Integration/Console/Fixtures/TestStringEnum.php

@@ -0,0 +1,12 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Tests\Tempest\Integration\Console\Fixtures;
+
+enum TestStringEnum: string
+{
+    case A = 'a';
+    case B = 'b';
+    case C = 'c';
+}

tests/Integration/Console/RenderConsoleCommandTest.php

@@ -46,7 +46,7 @@ public function test_render(): void
         (new RenderConsoleCommand($console))($consoleCommand);
 
         $this->assertSame(
-            'test <path> [times=1] [--force=false] - description',
+            'test <path> <type {a|b|c}> [fallback=a {a|b|c}] [times=1] [--force=false] - description',
             trim($output->getBufferWithoutFormatting()[0]),
         );
     }