REST API: Support type coercion when validating the `enum` JSON Schema keyword.

Previously, the `enum` keyword was validated by perform a strict equality check. For `string` types this is generally ok, but it prevented using alternative types like `number` when rich type support isn't available.

Now the same level of type coercion/sanitization is applied when validating `enum` as all other validation checks. This means that a value of `"1"` will be accepted for an `enum` of `[ 0, 1 ]`. Additionally, `object` types now properly ignore key order when checking for equality.

Props yakimun.
Fixes #51911.

Built from https://develop.svn.wordpress.org/trunk@50010


git-svn-id: http://core.svn.wordpress.org/trunk@49711 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/rest-api.php

@@ -1874,6 +1874,73 @@ function rest_find_one_matching_schema( $value, $args, $param, $stop_after_first
 	return $matching_schemas[0]['schema_object'];
 }
 
+/**
+ * Checks the equality of two values, following JSON Schema semantics.
+ *
+ * Property order is ignored for objects.
+ *
+ * Values must have been previously sanitized/coerced to their native types.
+ *
+ * @since 5.7.0
+ *
+ * @param mixed $value1 The first value to check.
+ * @param mixed $value2 The second value to check.
+ * @return bool True if the values are equal or false otherwise.
+ */
+function rest_are_values_equal( $value1, $value2 ) {
+	if ( is_array( $value1 ) && is_array( $value2 ) ) {
+		if ( count( $value1 ) !== count( $value2 ) ) {
+			return false;
+		}
+
+		foreach ( $value1 as $index => $value ) {
+			if ( ! array_key_exists( $index, $value2 ) || ! rest_are_values_equal( $value, $value2[ $index ] ) ) {
+				return false;
+			}
+		}
+
+		return true;
+	}
+
+	return $value1 === $value2;
+}
+
+/**
+ * Validates that the given value is a member of the JSON Schema "enum".
+ *
+ * @since 5.7.0
+ *
+ * @param mixed  $value  The value to validate.
+ * @param array  $args   The schema array to use.
+ * @param string $param  The parameter name, used in error messages.
+ * @return true|WP_Error True if the "enum" contains the value or a WP_Error instance otherwise.
+ */
+function rest_validate_enum( $value, $args, $param ) {
+	$sanitized_value = rest_sanitize_value_from_schema( $value, $args, $param );
+	if ( is_wp_error( $sanitized_value ) ) {
+		return $sanitized_value;
+	}
+
+	foreach ( $args['enum'] as $enum_value ) {
+		if ( rest_are_values_equal( $sanitized_value, $enum_value ) ) {
+			return true;
+		}
+	}
+
+	$encoded_enum_values = array();
+	foreach ( $args['enum'] as $enum_value ) {
+		$encoded_enum_values[] = is_scalar( $enum_value ) ? $enum_value : wp_json_encode( $enum_value );
+	}
+
+	if ( count( $encoded_enum_values ) === 1 ) {
+		/* translators: 1: Parameter, 2: Valid values. */
+		return new WP_Error( 'rest_not_in_enum', wp_sprintf( __( '%1$s is not %2$s.' ), $param, $encoded_enum_values[0] ) );
+	}
+
+	/* translators: 1: Parameter, 2: List of valid values. */
+	return new WP_Error( 'rest_not_in_enum', wp_sprintf( __( '%1$s is not one of %2$l.' ), $param, $encoded_enum_values ) );
+}
+
 /**
  * Get all valid JSON schema properties.
  *
@@ -2153,13 +2220,6 @@ function rest_validate_value_from_schema( $value, $args, $param = '' ) {
 		return true;
 	}
 
-	if ( ! empty( $args['enum'] ) ) {
-		if ( ! in_array( $value, $args['enum'], true ) ) {
-			/* translators: 1: Parameter, 2: List of valid values. */
-			return new WP_Error( 'rest_not_in_enum', sprintf( __( '%1$s is not one of %2$s.' ), $param, implode( ', ', $args['enum'] ) ) );
-		}
-	}
-
 	if ( in_array( $args['type'], array( 'integer', 'number' ), true ) ) {
 		if ( ! is_numeric( $value ) ) {
 			return new WP_Error(
@@ -2234,6 +2294,13 @@ function rest_validate_value_from_schema( $value, $args, $param = '' ) {
 		}
 	}
 
+	if ( ! empty( $args['enum'] ) ) {
+		$enum_contains_value = rest_validate_enum( $value, $args, $param );
+		if ( is_wp_error( $enum_contains_value ) ) {
+			return $enum_contains_value;
+		}
+	}
+
 	// The "format" keyword should only be applied to strings. However, for backward compatibility,
 	// we allow the "format" keyword if the type keyword was not specified, or was set to an invalid value.
 	if ( isset( $args['format'] )

wp-includes/version.php

@@ -13,7 +13,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.7-alpha-50009';
+$wp_version = '5.7-alpha-50010';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.