Struct QueryValidator 

pub struct QueryValidator { /* private fields */ }

Query Validator

Validates incoming GraphQL queries against security policies. Acts as the third layer in the security middleware pipeline.

Delegates AST-based analysis to RequestValidator from graphql::complexity — the single source of truth for depth, complexity, and alias-amplification logic.

Implementations

impl QueryValidator

pub const fn from_config(config: QueryValidatorConfig) -> Self

Create a new query validator from configuration

pub const fn permissive() -> Self

Create validator with permissive settings

pub const fn standard() -> Self

Create validator with standard settings

pub const fn strict() -> Self

Create validator with strict settings

pub fn validate(&self, query: &str) -> Result<QueryMetrics, SecurityError>

Validate a GraphQL query, enforcing all configured limits.

Performs checks in order:

1. Query size (O(1) — no parsing)
2. AST parse (rejects malformed GraphQL)
3. Query depth
4. Query complexity
5. Alias count (alias amplification protection)

Returns QueryMetrics if all checks pass, or the first SecurityError encountered.

Errors

Returns SecurityError::QueryTooLarge if the query exceeds max_size_bytes. Returns SecurityError::MalformedQuery if GraphQL syntax is invalid. Returns SecurityError::QueryTooDeep if nesting depth exceeds max_depth. Returns SecurityError::QueryTooComplex if complexity exceeds max_complexity. Returns SecurityError::TooManyAliases if alias count exceeds max_aliases.

pub fn validate_with_variables( &self, query: &str, variables: Option<&Value>, ) -> Result<QueryMetrics, SecurityError>

Validate a GraphQL query with the request’s variables available for pagination-argument resolution.

Identical to validate, except a variable-valued pagination argument (first: $n) is scored at its resolved value rather than at the fail-closed ceiling (#869). Callers that have the request variables must use this entry point, or legitimate variable-paginated queries are over-scored and rejected.

Errors

Same as validate.

pub const fn config(&self) -> &QueryValidatorConfig

Get the underlying configuration

Trait Implementations

impl Clone for QueryValidator

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for QueryValidator

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.