Add ChoiceEnumTrait & SimpleChoiceEnum

src/AutoDiscoveredValuesTrait.php

@@ -10,17 +10,50 @@
 
 namespace Elao\Enum;
 
+use Elao\Enum\Exception\LogicException;
+
+/**
+ * Auto-discover enumerated values from public constants.
+ */
 trait AutoDiscoveredValuesTrait
 {
     /** @var array */
     private static $guessedValues = [];
 
+    /** @var array */
+    private static $guessedReadables = [];
+
     /**
      * @see EnumInterface::values()
      *
      * @return int[]|string[]
      */
     public static function values(): array
+    {
+        return static::autodiscoveredValues();
+    }
+
+    /**
+     * @see ChoiceEnumTrait::choices()
+     */
+    protected static function choices(): array
+    {
+        if (!in_array(ChoiceEnumTrait::class, class_uses(self::class, false), true)) {
+            throw new LogicException(sprintf(
+                'Method "%s" is only meant to be used when using the "%s" trait which is not used in "%s"',
+                __METHOD__,
+                ChoiceEnumTrait::class,
+                static::class
+            ));
+        }
+
+        return static::autodiscoveredReadables();
+    }
+
+    /**
+     * @internal
+     */
+    private static function autodiscoveredValues(): array
     {
         $enumType = static::class;
 
@@ -45,4 +78,22 @@ public static function values(): array
 
         return self::$guessedValues[$enumType];
     }
+
+    /**
+     * @internal
+     */
+    private static function autodiscoveredReadables(): array
+    {
+        $enumType = static::class;
+
+        if (!isset(self::$guessedReadables[$enumType])) {
+            $constants = (new \ReflectionClass($enumType))->getConstants();
+            foreach (static::autodiscoveredValues() as $value) {
+                $constantName = array_search($value, $constants, true);
+                self::$guessedReadables[$enumType][$value] = ucfirst(strtolower(str_replace('_', ' ', $constantName)));
+            }
+        }
+
+        return self::$guessedReadables[$enumType];
+    }
 }

src/ChoiceEnumTrait.php

@@ -0,0 +1,76 @@
+<?php
+
+/*
+ * This file is part of the "elao/enum" package.
+ *
+ * Copyright (C) Elao
+ *
+ * @author Elao <contact@elao.com>
+ */
+
+namespace Elao\Enum;
+
+use Elao\Enum\Exception\LogicException;
+
+/**
+ * Discover readable enumerated values by returning the enumerated values as keys and their labels as values
+ * in {@link \Elao\Enum\ChoiceEnumTrait::choices()}, replacing the need to provide both:
+ * - {@link \Elao\Enum\ReadableEnumInterface::readables()}
+ * - {@link \Elao\Enum\ReadableEnumInterface::values()}
+ *
+ * Meant to be used within a {@link \Elao\Enum\ReadableEnumInterface} implementation.
+ */
+trait ChoiceEnumTrait
+{
+    /**
+     * @see EnumInterface::values()
+     *
+     * @return int[]|string[]
+     */
+    public static function values(): array
+    {
+        static::checkForChoiceEnumTraitMisuses();
+
+        $values = array_keys(static::choices());
+
+        if (is_a(static::class, FlaggedEnum::class, true)) {
+            $values = array_values(array_filter($values, function ($v): bool {
+                return 0 === ($v & $v - 1);
+            }));
+        }
+
+        return $values;
+    }
+
+    /**
+     * @see ReadableEnumInterface::readables()
+     *
+     * @return string[] labels indexed by enumerated value
+     */
+    public static function readables(): array
+    {
+        static::checkForChoiceEnumTraitMisuses();
+
+        return static::choices();
+    }
+
+    /**
+     * @return string[] The enumerated values as keys and their labels as values.
+     */
+    abstract protected static function choices(): array;
+
+    /**
+     * @internal
+     */
+    private static function checkForChoiceEnumTraitMisuses()
+    {
+        if (!is_a(static::class, ReadableEnumInterface::class, true)) {
+            throw new LogicException(sprintf(
+                'The "%s" trait is meant to be used by "%s" implementations, but "%s" does not implement it.',
+                ChoiceEnumTrait::class,
+                ReadableEnumInterface::class,
+                static::class
+            ));
+        }
+    }
+}

src/ReadableEnumInterface.php

@@ -17,7 +17,7 @@ interface ReadableEnumInterface extends EnumInterface
     /**
      * Gets an array of the human representations indexed by possible values.
      *
-     * @return array
+     * @return string[] labels indexed by enumerated value
      */
     public static function readables(): array;
 

src/SimpleChoiceEnum.php

@@ -0,0 +1,25 @@
+<?php
+
+/*
+ * This file is part of the "elao/enum" package.
+ *
+ * Copyright (C) Elao
+ *
+ * @author Elao <contact@elao.com>
+ */
+
+namespace Elao\Enum;
+
+/**
+ * An opinionated enum implementation:
+ *
+ * - auto-discovers enumerated values from public constants.
+ * - implements {@link \Elao\Enum\ReadableEnumInterface} with default labels identical to enumerated values.
+ */
+class SimpleChoiceEnum extends ReadableEnum
+{
+    use AutoDiscoveredValuesTrait;
+    use ChoiceEnumTrait {
+        ChoiceEnumTrait::values insteadof AutoDiscoveredValuesTrait;
+    }
+}

tests/Unit/AutoDiscoveredValuesTraitTest.php

@@ -35,6 +35,15 @@ public function testItAutoDiscoveredValuesBasedOnAvailableBitFlagConstants()
     {
         $this->assertSame([1, 2, 4], AutoDiscoveredFlaggedEnum::values());
     }
+
+    /**
+     * @expectedException \Elao\Enum\Exception\LogicException
+     * @expectedExceptionMessage Method "Elao\Enum\AutoDiscoveredValuesTrait::choices" is only meant to be used when using the "Elao\Enum\ChoiceEnumTrait" trait which is not used in "Elao\Enum\Tests\Unit\AutoDiscoveredEnumMisusingChoices"
+     */
+    public function testThrowsOnChoicesMisuses()
+    {
+        AutoDiscoveredEnumMisusingChoices::foo();
+    }
 }
 
 final class AutoDiscoveredEnum extends Enum
@@ -57,3 +66,15 @@ final class AutoDiscoveredFlaggedEnum extends FlaggedEnum
     const NOT_A_BIT_FLAG = 3;
     const NOT_EVEN_AN_INT = 'not_even_an_int';
 }
+
+final class AutoDiscoveredEnumMisusingChoices extends Enum
+{
+    use AutoDiscoveredValuesTrait;
+
+    const FOO = 'foo';
+
+    public static function foo()
+    {
+        self::choices();
+    }
+}

tests/Unit/ChoiceEnumTraitTest.php

@@ -0,0 +1,112 @@
+<?php
+
+/*
+ * This file is part of the "elao/enum" package.
+ *
+ * Copyright (C) Elao
+ *
+ * @author Elao <contact@elao.com>
+ */
+
+namespace Elao\Enum\Tests\Unit;
+
+use Elao\Enum\ChoiceEnumTrait;
+use Elao\Enum\Enum;
+use Elao\Enum\FlaggedEnum;
+use Elao\Enum\ReadableEnum;
+use PHPUnit\Framework\TestCase;
+
+class ChoiceEnumTraitTest extends TestCase
+{
+    public function testItProvidesValuesAndReadablesImplementations()
+    {
+        $this->assertSame(['foo', 'bar', 'baz'], ChoiceEnum::values());
+        $this->assertSame([
+            ChoiceEnum::FOO => 'Foo label',
+            ChoiceEnum::BAR => 'Bar label',
+            ChoiceEnum::BAZ => 'Baz label',
+        ], ChoiceEnum::readables());
+    }
+
+    public function testItFiltersValuesForFlaggedEnumImplementations()
+    {
+        $this->assertSame([1, 2, 4], FlaggedEnumWithChoiceEnumTrait::values());
+        $this->assertSame([
+            FlaggedEnumWithChoiceEnumTrait::EXECUTE => 'Execute',
+            FlaggedEnumWithChoiceEnumTrait::WRITE => 'Write',
+            FlaggedEnumWithChoiceEnumTrait::READ => 'Read',
+            FlaggedEnumWithChoiceEnumTrait::WRITE | FlaggedEnumWithChoiceEnumTrait::READ => 'Read & write',
+            FlaggedEnumWithChoiceEnumTrait::EXECUTE | FlaggedEnumWithChoiceEnumTrait::READ => 'Read & execute',
+            FlaggedEnumWithChoiceEnumTrait::ALL => 'All permissions',
+        ], FlaggedEnumWithChoiceEnumTrait::readables());
+    }
+
+    /**
+     * @expectedException \Elao\Enum\Exception\LogicException
+     * @expectedExceptionMessage The "Elao\Enum\ChoiceEnumTrait" trait is meant to be used by "Elao\Enum\ReadableEnumInterface" implementations, but "Elao\Enum\Tests\Unit\NonReadableEnumWithChoiceEnumTrait" does not implement it.
+     */
+    public function testValuesThrowsOnNonReadable()
+    {
+        NonReadableEnumWithChoiceEnumTrait::values();
+    }
+
+    /**
+     * @expectedException \Elao\Enum\Exception\LogicException
+     * @expectedExceptionMessage The "Elao\Enum\ChoiceEnumTrait" trait is meant to be used by "Elao\Enum\ReadableEnumInterface" implementations, but "Elao\Enum\Tests\Unit\NonReadableEnumWithChoiceEnumTrait" does not implement it.
+     */
+    public function testReadableThrowsOnNonReadable()
+    {
+        NonReadableEnumWithChoiceEnumTrait::readables();
+    }
+}
+
+final class ChoiceEnum extends ReadableEnum
+{
+    use ChoiceEnumTrait;
+
+    const FOO = 'foo';
+    const BAR = 'bar';
+    const BAZ = 'baz';
+
+    protected static function choices(): array
+    {
+        return [
+            static::FOO => 'Foo label',
+            static::BAR => 'Bar label',
+            static::BAZ => 'Baz label',
+        ];
+    }
+}
+
+final class FlaggedEnumWithChoiceEnumTrait extends FlaggedEnum
+{
+    use ChoiceEnumTrait;
+
+    const EXECUTE = 1;
+    const WRITE = 2;
+    const READ = 4;
+
+    const ALL = self::EXECUTE | self::WRITE | self::READ;
+
+    public static function choices(): array
+    {
+        return [
+            static::EXECUTE => 'Execute',
+            static::WRITE => 'Write',
+            static::READ => 'Read',
+            static::WRITE | static::READ => 'Read & write',
+            static::EXECUTE | static::READ => 'Read & execute',
+            static::ALL => 'All permissions',
+        ];
+    }
+}
+
+final class NonReadableEnumWithChoiceEnumTrait extends Enum
+{
+    use ChoiceEnumTrait;
+
+    protected static function choices(): array
+    {
+        return ['foo' => 'Foo label'];
+    }
+}

tests/Unit/SimpleChoiceEnumTest.php

@@ -0,0 +1,54 @@
+<?php
+
+/*
+ * This file is part of the "elao/enum" package.
+ *
+ * Copyright (C) Elao
+ *
+ * @author Elao <contact@elao.com>
+ */
+
+namespace Elao\Enum\Tests\Unit;
+
+use Elao\Enum\SimpleChoiceEnum;
+use PHPUnit\Framework\TestCase;
+
+class SimpleChoiceEnumTest extends TestCase
+{
+    public function testSimpleChoiceEnum()
+    {
+        $this->assertSame(['foo', 'bar', 'baz'], DummySimpleChoiceEnum::values());
+        $this->assertSame([
+            ChoiceEnum::FOO => 'Foo',
+            ChoiceEnum::BAR => 'Bar',
+            ChoiceEnum::BAZ => 'Baz',
+        ], DummySimpleChoiceEnum::readables());
+    }
+
+    public function testSimpleChoiceEnumWithLabelOverride()
+    {
+        $this->assertSame(['foo', 'bar', 'baz'], DummySimpleChoiceEnumWithLabelOverride::values());
+        $this->assertSame([
+            ChoiceEnum::FOO => 'Foo label',
+            ChoiceEnum::BAR => 'Bar',
+            ChoiceEnum::BAZ => 'Baz',
+        ], DummySimpleChoiceEnumWithLabelOverride::readables());
+    }
+}
+
+class DummySimpleChoiceEnum extends SimpleChoiceEnum
+{
+    const FOO = 'foo';
+    const BAR = 'bar';
+    const BAZ = 'baz';
+}
+
+final class DummySimpleChoiceEnumWithLabelOverride extends DummySimpleChoiceEnum
+{
+    protected static function choices(): array
+    {
+        return array_replace(parent::choices(), [
+            static::FOO => 'Foo label',
+        ]);
+    }
+}