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<?php |
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|
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if (!defined('ABSPATH')) { |
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exit; |
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} |
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|
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/** |
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* Schema-contract validator for JS-to-PHP wire payloads. |
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* |
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* Single source of truth for the *shape* of any payload that crosses a |
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* process boundary (PHP to server HTTP POST, JS to PHP AJAX POST). Each |
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* payload has a `*.schema.php` file under `includes/schema/` that returns an |
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* associative array describing every field; the producer is contract-tested |
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* to match it. |
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* |
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* Why this exists. Commit 4080ffb5 ("fix five schema-mismatch and |
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* reliability bugs") landed five independent bugs in one fix because the |
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* JS payload builder, the PHP builder, and the server endpoint each |
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* encoded the schema independently with no shared spec. Same class of |
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* defect produced 35380dcc and earlier fixes. A single declared schema |
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* plus a producer-side contract test would have caught all five at |
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* unit-test time. |
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* |
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* Why not opis/json-schema or another lib. A hand-rolled spec is smaller |
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* than the JSON-Schema-of-JSON-Schema, has zero new composer deps, and |
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* only needs to encode the contracts that have historically broken |
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* (field name, primitive type, optional vs required, item types inside |
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* arrays/objects). The lib is callable from any context (boot, tests, |
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* future JS via a generator) and degrades gracefully if a field |
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* specifier is malformed. |
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* |
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* Spec grammar. A schema is `array<string, FieldSpec>` where each |
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* FieldSpec is an associative array with these keys: |
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* |
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* - `type` (string, required): one of `string`, `int`, `bool`, `array`, |
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* `object`, `string|null`, `int|null`, `bool|null`, `array|null`, |
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* `object|null`, `mixed`. `object` matches a non-empty associative |
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* array (PHP has no first-class object distinct from assoc-array on |
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* the wire). `mixed` is an escape hatch; use sparingly. |
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* - `required` (bool, default true): whether the key MUST exist on the |
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* payload. Required + null-allowed means the key is present but the |
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* value may be null. |
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* - `item_type` (string, optional): when `type` is `array`, every |
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* element must match this primitive type. Default: no item check. |
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* - `key_type` (string, optional): when `type` is `object`, every key |
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* must match this type (typically `string`). Default: `string`. |
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* - `value_type` (string, optional): when `type` is `object`, every |
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* value must match this primitive type. Default: no value check. |
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* - `enum` (array<scalar>, optional): when present, the value must be |
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* strictly equal to one of the listed scalars. Stricter than `type` |
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* alone. |
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* - `description` (string, optional): human-readable note. Ignored at |
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* runtime; used by docs / future codegen. |
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* |
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* Unknown fields on the payload are reported as `unexpected_field` |
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* violations. The schema is the closed contract: any new field on the |
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* producer must be added to the schema in the same commit. |
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* |
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* Single entry point. `validate(array $schema, array $payload): |
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* array<int, string>` returns a list of human-readable violation strings, |
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* empty when the payload conforms. Callers assert `$violations === []` |
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* in tests, with the list embedded in the failure message so the test |
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* report names the exact field(s) that drifted. |
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*/ |
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class ABJ_404_Solution_PayloadSchema { |
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|
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/** |
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* Validate a payload against a schema. |
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* |
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* @param array<string, array<string, mixed>> $schema FieldSpec map. |
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* @param array<string, mixed> $payload Wire payload to check. |
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* @param string $path Dotted path prefix used in recursive calls |
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* and for error messages. Empty at the top level. |
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* @return array<int, string> Violation messages, empty on success. |
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*/ |
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public static function validate(array $schema, array $payload, string $path = ''): array { |
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$violations = []; |
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|
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foreach ($schema as $field => $spec) { |
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$fieldPath = $path === '' ? (string)$field : $path . '.' . $field; |
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$required = !isset($spec['required']) || $spec['required'] === true; |
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|
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if (!array_key_exists($field, $payload)) { |
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if ($required) { |
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$violations[] = sprintf('missing required field: %s', $fieldPath); |
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} |
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continue; |
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} |
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|
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$value = $payload[$field]; |
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$type = isset($spec['type']) && is_string($spec['type']) ? $spec['type'] : 'mixed'; |
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|
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$typeViolation = self::checkType($fieldPath, $type, $value); |
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if ($typeViolation !== null) { |
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$violations[] = $typeViolation; |
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continue; |
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} |
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|
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if (isset($spec['enum']) && is_array($spec['enum'])) { |
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if (!in_array($value, $spec['enum'], true)) { |
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$violations[] = sprintf( |
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'%s value %s is not in enum [%s]', |
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$fieldPath, |
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self::renderScalar($value), |
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implode(', ', array_map([self::class, 'renderScalar'], $spec['enum'])) |
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); |
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continue; |
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} |
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} |
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|
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if (self::baseType($type) === 'array' && is_array($value) && isset($spec['item_type'])) { |
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$itemType = (string)$spec['item_type']; |
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foreach ($value as $i => $item) { |
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$v = self::checkType($fieldPath . '[' . $i . ']', $itemType, $item); |
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if ($v !== null) { |
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$violations[] = $v; |
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} |
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} |
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} |
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|
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if (self::baseType($type) === 'object' && is_array($value)) { |
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$keyType = isset($spec['key_type']) ? (string)$spec['key_type'] : 'string'; |
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$valueType = isset($spec['value_type']) ? (string)$spec['value_type'] : null; |
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foreach ($value as $k => $v) { |
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$kV = self::checkType($fieldPath . '/key', $keyType, $k); |
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if ($kV !== null) { |
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$violations[] = $kV; |
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} |
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if ($valueType !== null) { |
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$vV = self::checkType($fieldPath . '[' . self::renderScalar($k) . ']', $valueType, $v); |
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if ($vV !== null) { |
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$violations[] = $vV; |
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} |
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} |
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} |
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} |
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} |
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|
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foreach ($payload as $key => $_value) { |
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if (!array_key_exists($key, $schema)) { |
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$fieldPath = $path === '' ? (string)$key : $path . '.' . $key; |
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$violations[] = sprintf('unexpected_field: %s (not declared in schema)', $fieldPath); |
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} |
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} |
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|
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return $violations; |
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} |
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|
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/** |
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* Check a single value against a primitive type spec. Returns null |
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* when the value matches, a violation string otherwise. |
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* |
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* @param string $path |
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* @param string $type |
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* @param mixed $value |
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* @return string|null |
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*/ |
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private static function checkType(string $path, string $type, $value): ?string { |
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$allowNull = self::typeAllowsNull($type); |
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if ($value === null) { |
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return $allowNull ? null : sprintf('%s is null but type %s disallows null', $path, $type); |
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} |
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$base = self::baseType($type); |
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switch ($base) { |
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case 'string': |
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return is_string($value) ? null : self::typeMismatch($path, 'string', $value); |
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case 'int': |
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return is_int($value) ? null : self::typeMismatch($path, 'int', $value); |
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case 'bool': |
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return is_bool($value) ? null : self::typeMismatch($path, 'bool', $value); |
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case 'array': |
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if (!is_array($value)) { |
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return self::typeMismatch($path, 'array', $value); |
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} |
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if (self::isAssoc($value)) { |
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return sprintf('%s expected array (list), got object (associative)', $path); |
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} |
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return null; |
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case 'object': |
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if (!is_array($value)) { |
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return self::typeMismatch($path, 'object', $value); |
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} |
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if ($value !== [] && !self::isAssoc($value)) { |
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return sprintf('%s expected object (associative), got list', $path); |
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} |
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return null; |
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case 'mixed': |
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return null; |
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default: |
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return sprintf('%s schema type %s is unknown to the validator', $path, $type); |
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} |
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} |
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|
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private static function typeAllowsNull(string $type): bool { |
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return substr($type, -5) === '|null' || $type === 'mixed'; |
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} |
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|
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private static function baseType(string $type): string { |
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if (substr($type, -5) === '|null') { |
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return substr($type, 0, -5); |
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} |
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return $type; |
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} |
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|
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/** |
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* @param mixed $value |
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*/ |
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private static function typeMismatch(string $path, string $expected, $value): string { |
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return sprintf('%s expected %s, got %s', $path, $expected, self::describeType($value)); |
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} |
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|
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/** |
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* @param mixed $value |
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*/ |
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private static function describeType($value): string { |
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if (is_array($value)) { |
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return self::isAssoc($value) ? 'object' : 'array'; |
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} |
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return gettype($value); |
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} |
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|
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/** |
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* Render a scalar for error messages. Falls back to gettype() for |
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* non-scalars so the message stays readable even when the value is |
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* an array or object. |
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* |
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* @param mixed $value |
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*/ |
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private static function renderScalar($value): string { |
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if (is_string($value)) { |
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return "'" . $value . "'"; |
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} |
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if (is_int($value) || is_float($value)) { |
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return (string)$value; |
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} |
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if (is_bool($value)) { |
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return $value ? 'true' : 'false'; |
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} |
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if ($value === null) { |
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return 'null'; |
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} |
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return self::describeType($value); |
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} |
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|
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/** |
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* @param array<mixed, mixed> $arr |
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*/ |
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private static function isAssoc(array $arr): bool { |
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if ($arr === []) { |
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return false; |
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} |
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// array_is_list() is PHP 8.1+; plugin still supports 7.4. Use the |
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// canonical pre-8.1 idiom: a list has int-keyed sequential keys 0..N-1. |
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return array_keys($arr) !== range(0, count($arr) - 1); |
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} |
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} |
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|
