Support multiple arrays in intersect_key_recursive()

This makes a slight tweak on top of intersect_key_recursive() to allow for the passing of any number of arrays.

Author: borkweb

docs/classes/StellarWP/Arrays/Arr.md

@@ -1661,7 +1661,7 @@ public static wrap(mixed $value): array
 Recursively computes the intersection of arrays using keys for comparison.
 
 ```php
-public static intersect_key_recursive(array $array1, array $array2): array
+public static intersect_key_recursive(array $array, array $arrays): array
 ```
 
 
@@ -1675,13 +1675,14 @@ public static intersect_key_recursive(array $array1, array $array2): array
 
 | Parameter | Type | Description |
 |-----------|------|-------------|
-| `$array1` | **array** | The array with master keys to check. |
-| `$array2` | **array** | An array to compare keys against. |
+| `$array` | **array** | The array with master keys to check. |
+| `$arrays` | **array** | Additional arrays to compare keys against. |
 
 
 **Return Value:**
 
-An associative array containing all the entries of array1 which have keys that are present in all arguments.
+An associative array containing all the entries of $array
+whose keys exist in every provided array, recursively.
 
 
 

src/Arrays/Arr.php

@@ -1422,20 +1422,37 @@ public static function wrap( $value ) {
 	/**
 	 * Recursively computes the intersection of arrays using keys for comparison.
 	 *
-	 * @param mixed[] $array1 The array with master keys to check.
-	 * @param mixed[] $array2 An array to compare keys against.
+	 * @param mixed[] $array     The array with master keys to check.
+	 * @param mixed[] ...$arrays Additional arrays to compare keys against.
 	 *
-	 * @return mixed[] An associative array containing all the entries of array1 which have keys that are present in all arguments.
+	 * @return mixed[] An associative array containing all the entries of $array
+	 *                 whose keys exist in every provided array, recursively.
 	 */
-	public static function intersect_key_recursive( array $array1, array $array2 ): array {
-		$array1 = array_intersect_key( $array1, $array2 );
+	public static function intersect_key_recursive( array $array, array ...$arrays ): array {
+		$array = array_intersect_key( $array, ...$arrays );
 
-		foreach ( $array1 as $key => $value ) {
-			if ( is_array( $value ) && is_array( $array2[ $key ] ) ) {
-				$array1[ $key ] = static::intersect_key_recursive( $value, $array2[ $key ] );
+		foreach ( $array as $key => $value ) {
+			if ( ! is_array( $value ) ) {
+				continue;
+			}
+
+			$arrays_to_intersect = [];
+			foreach ( $arrays as $intersect_array ) {
+				if ( ! isset( $intersect_array[ $key ] ) || ! is_array( $intersect_array[ $key ] ) ) {
+					unset( $array[ $key ] );
+					continue 2;
+				}
+
+				$arrays_to_intersect[] = $intersect_array[ $key ];
+			}
+
+			if ( empty( $arrays_to_intersect ) ) {
+				continue;
 			}
+
+			$array[ $key ] = static::intersect_key_recursive( $value, ...$arrays_to_intersect );
 		}
 
-		return $array1;
+		return $array;
 	}
 }

tests/wpunit/IntersectKeyRecursiveTest.php

@@ -198,23 +198,57 @@ public function test_with_multiple_arrays(): void {
 			'a' => 1,
 			'b' => 2,
 			'c' => 3,
+			'd' => [
+				'x' => 1,
+				'y' => [
+					'a' => 1,
+					'b' => 2,
+				],
+				'z' => [
+					'a' => 1,
+					'b' => 2,
+				],
+			],
 		];
 
 		$array2 = [
 			'a' => 10,
 			'b' => 20,
+			'd' => [
+				'y' => [
+					'a' => 1,
+					'b' => 2,
+				],
+				'z' => 2,
+			],
 		];
 
 		$array3 = [
 			'a' => 100,
 			'c' => 300,
+			'd' => [
+				'x' => 1,
+				'y' => [
+					'a' => 1,
+					'b' => 2,
+				],
+				'z' => [
+					'a' => 1,
+					'b' => 2,
+				],
+			],
 		];
 
-		$result1 = Arr::intersect_key_recursive( $array1, $array2 );
-		$result2 = Arr::intersect_key_recursive( $result1, $array3 );
+		$result = Arr::intersect_key_recursive( $array1, $array2, $array3 );
 
 		$this->assertEquals( [
 			'a' => 1,
-		], $result2 );
+			'd' => [
+				'y' => [
+					'a' => 1,
+					'b' => 2,
+				],
+			],
+		], $result );
 	}
 }