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predicate

Predicate and resolver helpers for decorators.

A decorator (see @graphql-markdown/types's DecoratorDefinition) is selected by a predicate over the node being printed, rather than by a fixed directive name. This module provides the common building blocks: matching a directive, matching an entity kind, composing predicates, and reading a directive's occurrences as decorator values.

always()​

function always(): DecoratorPredicate;

Defined in: packages/graphql/src/predicate.ts:191

A predicate that always matches, regardless of the node being printed.

Returns​

DecoratorPredicate

a DecoratorPredicate that is always true.

and()​

function and(...predicates): DecoratorPredicate;

Defined in: packages/graphql/src/predicate.ts:145

Combines predicates with logical AND. An empty list is vacuously true.

Parameters​

predicates​

...DecoratorPredicate[]

the predicates to combine.

Returns​

DecoratorPredicate

a DecoratorPredicate true when every one of predicates is true.

directiveOccurrence()​

function directiveOccurrence(name): DecoratorResolver;

Defined in: packages/graphql/src/predicate.ts:277

Builds a resolver reading a single, non-repeatable directive's argument values off the node being printed (see getTypeDirectiveValues, which this delegates to). Use directiveOccurrences instead for a repeatable directive, where more than one occurrence can carry values.

Parameters​

name​

string

the schema directive name to read.

Returns​

DecoratorResolver

a DecoratorResolver resolving that directive's single occurrence as a one-record array, or an empty array when the schema, the directive, or that occurrence is absent.

directiveOccurrences()​

function directiveOccurrences(name): DecoratorResolver;

Defined in: packages/graphql/src/predicate.ts:260

Builds a resolver reading every occurrence of a directive off the node being printed, as one record of arguments per occurrence (see getTypeDirectiveValuesList, which this delegates to and which also covers repeatable directives).

Parameters​

name​

string

the schema directive name to read.

Returns​

DecoratorResolver

a DecoratorResolver resolving that directive's occurrences, or an empty array when the schema or the directive is absent.

getDirectiveFromSchema()​

function getDirectiveFromSchema(name, options): Maybe<GraphQLDirective>;

Defined in: packages/graphql/src/predicate.ts:214

Resolves a schema directive definition by name.

Shared by directiveOccurrences (which reads a directive's argument values off a node) and @graphql-markdown/printer-legacy's decorator resolution (which also needs the directive definition itself, for a decorator's render context) — both need "look up this named directive on options.schema, safely", so it lives here once rather than being reimplemented at each call site.

Parameters​

name​

string

the schema directive name to resolve.

options​

PrintTypeOptions

the print options in effect; options.schema is read.

Returns​

Maybe<GraphQLDirective>

the directive definition, or undefined when options.schema is absent, not a GraphQLSchema, or does not declare a directive named name.

getSchemaEntity()​

function getSchemaEntity(type, options): Maybe<SchemaEntity>;

Defined in: packages/graphql/src/predicate.ts:52

Resolves the schema entity kind of the type being printed.

The kind is taken from the print options when the caller knows it, as only the caller can tell a query from a mutation. It falls back to the type guards otherwise, which cover every kind but the operations.

Parameters​

type​

unknown

the GraphQL type being printed.

options​

PrintTypeOptions

the print options in effect.

Returns​

Maybe<SchemaEntity>

the schema entity kind, or undefined when it cannot be determined.

hasAnyDirective()​

function hasAnyDirective(): DecoratorPredicate;

Defined in: packages/graphql/src/predicate.ts:115

Builds a predicate matching a node carrying any directive at all.

Returns​

DecoratorPredicate

a DecoratorPredicate true when the node carries at least one directive.

hasDirectiveNamed()​

function hasDirectiveNamed(name): DecoratorPredicate;

Defined in: packages/graphql/src/predicate.ts:97

Builds a predicate matching a node carrying a specific directive.

Parameters​

name​

string

the schema directive name to match.

Returns​

DecoratorPredicate

a DecoratorPredicate true when the node carries @name.

Example​

decorators: {
  responses: {
    predicate: hasDirectiveNamed("httpResponse"),
    render: (values) => values.map((v) => `- ${v.code}`).join("\n"),
  },
}

isEntity()​

function isEntity(...kinds): DecoratorPredicate;

Defined in: packages/graphql/src/predicate.ts:130

Builds a predicate matching one of the given schema entity kinds.

Parameters​

kinds​

...SchemaEntity[]

the schema entity kinds to match.

Returns​

DecoratorPredicate

a DecoratorPredicate true when the node's resolved entity kind is one of kinds.

not()​

function not(predicate): DecoratorPredicate;

Defined in: packages/graphql/src/predicate.ts:179

Negates a predicate.

Parameters​

predicate​

DecoratorPredicate

the predicate to negate.

Returns​

DecoratorPredicate

a DecoratorPredicate true when predicate is false.

or()​

function or(...predicates): DecoratorPredicate;

Defined in: packages/graphql/src/predicate.ts:163

Combines predicates with logical OR. An empty list is vacuously false.

Parameters​

predicates​

...DecoratorPredicate[]

the predicates to combine.

Returns​

DecoratorPredicate

a DecoratorPredicate true when at least one of predicates is true.