@eleven-am/nestjs-graphql-crud/types.ts

nestjs-graphql-crud is a library that aims to reduce the boilerplate code needed to create a GraphQL CRUD API.

// index.d.ts (Updated Version with Custom Resolver Support and FindManyArgs)

import {DynamicModule, ForwardReference, Provider, Type} from '@nestjs/common';
import {GraphQLResolveInfo} from 'graphql';
import {AppAbilityType, Permission, WillAuthorize} from '@eleven-am/authorizer';
import {PrismaClient} from '@prisma/client';
import {Abstract} from "@nestjs/common/interfaces/abstract.interface";

/**
 * A function type that returns the value when called.
 * Used for lazy evaluation of types to avoid circular dependencies.
 */
export type Getter<T> = () => T;

/**
 * Type helper to extract parameter types from a method.
 * Specifically designed to extract the first argument from methods with the
 * signature (arg1: T, ability: AppAbilityType, select: any).
 */
export type ParametersOfMethod<Target, Method extends keyof Target> = Target[Method] extends (...args: any[]) => any
	? Parameters<Target[Method]> extends [infer Argument, AppAbilityType, any] ? Argument : never
	: never;

export type ParametersOfResolveMethod<Item, Target, Method extends keyof Target> = Target[Method] extends (...args: any[]) => any
	? Parameters<Target[Method]> extends [infer Argument, AppAbilityType, Item, any] ? Argument : never
	: never;

/**
 * Type helper to extract a return type from a method.
 */
export type ReturnTypeOfMethod<Target, Method extends keyof Target> = Target[Method] extends (...args: any[]) => any
	? ReturnType<Target[Method]>
	: never;

/**
 * Interface for FindMany query parameters
 *
 * @template WhereInput - The type of the where input
 */
export declare class FindManyContract<WhereInput> {
	/** Filter criteria */
	where?: WhereInput;
	/** Pagination parameters */
	pagination?: PaginationContract;
}

/**
 * Defines the structure for pagination arguments.
 * Used within operations that retrieve lists of entities.
 */
export interface PaginationContract {
	/** Maximum number of records to return (e.g., page size). */
	take: number;
	/** Number of records to skip (e.g., for offset pagination). */
	skip: number;
}

/**
 * Represents the result of parsing GraphQL field selections.
 * This structure can be used by DataProvider implementations to optimize data fetching
 * by selecting only the necessary fields.
 * @template EntityType The entity type whose fields are being selected.
 */
export interface FieldSelectionResult<EntityType> {
	/**
	 * A nested structure indicating which fields were requested.
	 * `true` indicates a scalar or enum field.
	 * A nested object indicates relation fields, recursively defining selections within the relation.
	 */
	select: {
		[K in keyof EntityType]?: EntityType[K] extends Array<infer U> ?
			(U extends object ? FieldSelectionResult<U> : boolean) : // Handle arrays of objects vs arrays of scalars
			EntityType[K] extends object ?
				FieldSelectionResult<EntityType[K]> : // Handle nested objects
				boolean; // Handle scalar fields
	};
}

/**
 * Interface for a service that can parse GraphQL query info (`GraphQLResolveInfo`)
 * to determine the specific fields requested by a client.
 * Implement this interface to provide logic for understanding field selections,
 * typically used to optimize database queries within a `DataProvider`.
 */
export interface FieldSelectionProvider {
	/**
	 * Parses the GraphQL resolver info to extract the requested fields.
	 * @param info The `GraphQLResolveInfo` object provided by the GraphQL execution engine.
	 * @returns A structured representation (`FieldSelectionResult`) of the selected fields.
	 * @template EntityType The entity type being queried.
	 */
	parseSelection<EntityType>(info: GraphQLResolveInfo): FieldSelectionResult<EntityType>;
}

/**
 * Interface defining the contract for data persistence operations (CRUD).
 * This is a crucial interface to implement for connecting the library to a specific
 * database or ORM (e.g., Prisma, TypeORM). Implementations handle the actual
 * data fetching and manipulation, often integrating authorization checks.
 */
export interface DataProvider {
	/**
	 * Finds a single entity matching the given criteria, respecting authorization rules.
	 * @param modelName The logical name or identifier of the data model/table.
	 * @param ability The authorization ability object for the current user/request context.
	 * @param where The filter criteria used to find the specific entity.
	 * @param select A structure indicating which fields of the entity should be returned.
	 * @returns A promise resolving to the found entity object or null if not found or not permitted.
	 * @template EntityType The type of the entity being queried.
	 * @template WhereInputType The type defining the filter criteria.
	 */
	findOne<EntityType, WhereInputType>(modelName: string, ability: AppAbilityType, where: WhereInputType, select: Record<string, boolean>): Promise<EntityType | null>;
	
	/**
	 * Finds multiple entities matching the given criteria, respecting authorization and pagination.
	 * Updated to support both simple pagination and advanced Prisma-style options.
	 * @param modelName The logical name or identifier of the data model/table.
	 * @param ability The authorization ability object for the current user/request context.
	 * @param args An object containing filter criteria, pagination, and optional advanced options like orderBy, cursor, distinct.
	 * @param select A structure indicating which fields should be returned for each entity.
	 * @returns A promise resolving to an array of found entities.
	 * @template EntityType The type of the entity being queried.
	 * @template WhereInputType The type defining the filter criteria.
	 */
	findMany<EntityType, WhereInputType>(modelName: string, ability: AppAbilityType, args: {
		where: WhereInputType;
		pagination?: PaginationContract;
		orderBy?: Record<string, 'asc' | 'desc'> | Array<Record<string, 'asc' | 'desc'>>;
		cursor?: any;
		distinct?: string[];
	}, select: Record<string, boolean>): Promise<EntityType[]>;
	
	/**
	 * Creates a new entity with the given data. Authorization for creation might be handled
	 * separately or assumed before calling this method.
	 * @param modelName The logical name or identifier of the data model/table.
	 * @param data The data object for the new entity.
	 * @param select A structure indicating which fields of the newly created entity should be returned.
	 * @returns A promise resolving to the newly created entity object.
	 * @template EntityType The type of the entity being created.
	 * @template CreateInputType The type defining the input data for creation.
	 */
	create<EntityType, CreateInputType>(modelName: string, data: CreateInputType, select: Record<string, boolean>): Promise<EntityType>;
	
	/**
	 * Updates a single entity identified by its ID, respecting authorization rules.
	 * @param modelName The logical name or identifier of the data model/table.
	 * @param ability The authorization ability object for the current user/request context.
	 * @param data The data object containing the fields to update.
	 * @param whereId The unique identifier (usually ID) of the entity to update.
	 * @param select A structure indicating which fields of the updated entity should be returned.
	 * @returns A promise resolving to the updated entity object.
	 * @template EntityType The type of the entity being updated.
	 * @template UpdateInputType The type defining the input data for updates.
	 */
	update<EntityType, UpdateInputType>(modelName: string, ability: AppAbilityType, data: UpdateInputType, whereId: string, select: Record<string, boolean>): Promise<EntityType>;
	
	/**
	 * Updates multiple entities matching the given criteria, respecting authorization rules.
	 * Note: The capability to return the updated entities might depend on the underlying ORM.
	 * Implementations might need to pre-fetch IDs or re-fetch data if the ORM doesn't support returning updated records directly.
	 * @param modelName The logical name or identifier of the data model/table.
	 * @param ability The authorization ability object for the current user/request context.
	 * @param data The data object containing the fields to apply to the matched entities.
	 * @param where The filter criteria to identify the entities to update.
	 * @param select A structure indicating which fields should be returned (may require complex implementation).
	 * @returns A promise resolving to an array of updated entity objects (implementation might vary).
	 * @template EntityType The type of the entity being updated.
	 * @template UpdateInputType The type defining the input data for updates.
	 * @template WhereInputType The type defining the filter criteria.
	 */
	updateMany<EntityType, UpdateInputType, WhereInputType>(modelName: string, ability: AppAbilityType, data: UpdateInputType, where: WhereInputType, select: Record<string, boolean>): Promise<EntityType[]>;
	
	/**
	 * Deletes a single entity identified by its ID, respecting authorization rules.
	 * @param modelName The logical name or identifier of the data model/table.
	 * @param ability The authorization ability object for the current user/request context.
	 * @param whereId The unique identifier (usually ID) of the entity to delete.
	 * @param select A structure indicating which fields of the deleted entity should be returned.
	 * @returns A promise resolving to the deleted entity object.
	 * @template EntityType The type of the entity being deleted.
	 */
	delete<EntityType>(modelName: string, ability: AppAbilityType, whereId: string, select: Record<string, boolean>): Promise<EntityType>;
	
	/**
	 * Deletes multiple entities matching the given criteria, respecting authorization rules.
	 * Note: The capability to return the deleted entities might depend on the underlying ORM.
	 * Implementations might need to pre-fetch matching entities before deletion.
	 * @param modelName The logical name or identifier of the data model/table.
	 * @param ability The authorization ability object for the current user/request context.
	 * @param where The filter criteria to identify the entities to delete.
	 * @param select A structure indicating which fields should be returned (may require pre-fetching).
	 * @returns A promise resolving to an array of deleted entity objects (implementation might vary).
	 * @template EntityType The type of the entity being deleted.
	 * @template WhereInputType The type defining the filter criteria.
	 */
	deleteMany<EntityType, WhereInputType>(modelName: string, ability: AppAbilityType, where: WhereInputType, select: Record<string, boolean>): Promise<EntityType[]>;
}

/**
 * Interface defining the contract for filtering and resolving GraphQL subscription updates.
 * Implement this interface to provide custom logic for how subscription events generated
 * by the CRUD service are filtered for specific clients and how the final payload is shaped.
 * Used with `CrudModuleConfig.withSubscription`.
 *
 * @template EntityType The entity type being tracked by the subscription.
 * @template FilterType The type defining the filter criteria provided by the client when subscribing.
 */
export interface SubscriptionResolver<EntityType, FilterType> {
	/**
	 * Determines if a specific subscriber, based on their filter criteria,
	 * should receive the notification about the given changes.
	 * @param filter The filter criteria provided by the specific subscriber.
	 * @param changes An array of entities that have changed (created, updated, or deleted) and triggered the event.
	 * @returns `true` if the subscriber should receive the update based on their filter, `false` otherwise.
	 */
	filter(filter: FilterType, changes: EntityType[]): boolean;
	
	/**
	 * Processes or transforms the changed entities before sending them to the subscriber.
	 * This method is called only if `filter` returns `true`. It can be used to fetch additional data,
	 * shape the output according to the client's needs, or perform other transformations.
	 * @param filter The filter criteria provided by the specific subscriber.
	 * @param changes An array of entities that have changed and passed the `filter` check.
	 * @param select The selection criteria indicating which fields should be included in the response.
	 * @returns A promise resolving to the array of entities (potentially transformed) to be sent to the subscriber.
	 */
	resolve(filter: FilterType, changes: EntityType[], select: any): Promise<EntityType[]>;
}

/**
 * A generic constructor type representing a class constructor.
 * @template Class The class type.
 * @template Parameters The types of the constructor parameters.
 */
export type Constructor<Class, Parameters extends any[] = any[]> = new (...args: Parameters) => Class;

/**
 * Defines the configuration for resolving a standard one-to-many relationship
 * (e.g., a User has many Posts, where Post has a `userId` field).
 * Used as input for `CrudModuleConfig.addRelation`.
 *
 * @template Target The related entity type (the "many" side, e.g., `Post`).
 * @template WhereInput Input type for filtering the related entities (e.g., `PostWhereInput`).
 */
export interface OneToManyRelationResolverConfig<Target, WhereInput> {
	/** The name of the field in the GraphQL schema representing this relation (e.g., "posts"). */
	fieldName: string;
	/** The logical name or identifier of the related model (e.g., Prisma model name "post"). */
	targetModel: string;
	/** Optional input type class used for filtering related entities in the GraphQL query. */
	targetWhereInput?: Type<WhereInput>;
	/** The class representing the related entity type (e.g., `Post`). */
	targetType: Type<Target>;
	/** Whether the filter argument (`targetWhereInput`) is nullable in the GraphQL schema. */
	whereNullable: boolean;
	/** The name of the field on the related entity (`Target`) that holds the foreign key referencing the parent entity's ID (e.g., "userId" on the `Post` entity). */
	relationField: keyof Target & string;
}

/**
 * Interface for a one-to-one relation configuration.
 * Used to define relationships where one entity relates to exactly one instance of another entity.
 *
 * @template Item The parent entity type
 * @template Target The related entity type
 */
export interface OneToOneRelationResolverConfig<Item, Target> {
	/** The name of the field in the GraphQL schema */
	fieldName: string;
	/** The name of the target model */
	targetModel: string;
	/** The class representing the target entity */
	targetType: Type<Target>;
	/** The name of the field on the parent entity that holds the foreign key */
	relationField: keyof Item;
	/** Whether the relation field is nullable */
	nullable?: boolean;
}

/**
 * Base configuration builder for CRUD modules with common functionality.
 *
 * @template Item The entity type
 * @template CreateInput The input type for create operations
 * @template UpdateInput The input type for update operations
 * @template UpdateManyInput The input type for update many operations
 * @template WhereInput The input type for query filters
 */
export declare class BaseCrudModuleConfig<
	Item,
> {
	/**
	 * Adds a one-to-many relation resolver to the module.
	 *
	 * @template Target The related entity type
	 * @template TargetWhereInput The input type for filtering related entities
	 * @param config Configuration for the one-to-many relation resolver
	 * @returns The configuration builder for chaining
	 */
	addRelation<Target, TargetWhereInput>(
		config: OneToManyRelationResolverConfig<Target, TargetWhereInput>
	): this;
	
	/**
	 * Adds a one-to-one relation resolver to the module.
	 *
	 * @template Target The related entity type
	 * @param config Configuration for the one-to-one relation resolver
	 * @returns The configuration builder for chaining
	 */
	addOneToOneRelation<Target>(
		config: OneToOneRelationResolverConfig<Item, Target>
	): this;
	
	/**
	 * Adds a custom subscription resolver to the module.
	 *
	 * @template FilterType The filter type for subscriptions
	 * @param config Configuration for the subscription resolver
	 * @returns The configuration builder for chaining
	 */
	withSubscription<FilterType>(config: {
		filter: Type<FilterType>;
		resolver: Type<SubscriptionResolver<Item, FilterType>>;
	}): this;
	
	/**
	 * Adds custom providers to the module.
	 *
	 * @param providers The provider classes to add
	 * @returns The configuration builder for chaining
	 */
	withProviders(...providers: Type[]): this;
	
	/**
	 * Adds custom controllers to the module.
	 *
	 * @param controllers The controller classes to add
	 * @returns The configuration builder for chaining
	 */
	withControllers(...controllers: Type[]): this;
	
	/**
	 * Adds custom authorizers to the module
	 *
	 * @param {...Type<WillAuthorize>[]} authorizer - The authorizer classes to add
	 * @returns {this} The configuration builder (for method chaining)
	 */
	withAuthorization(...authorizer: Type<WillAuthorize>[]): this;
	
	/**
	 * Adds imports to the module.
	 *
	 * @param imports The modules to import
	 * @returns The configuration builder for chaining
	 */
	import(...imports: (Type | DynamicModule | Promise<DynamicModule> | ForwardReference)[]): this;
	
	/**
	 * Adds exports to the module.
	 *
	 * @param exports The providers or modules to export
	 * @returns The configuration builder for chaining
	 */
	export(...exports: (DynamicModule | string | symbol | Provider | ForwardReference | Abstract<any> | Function)[]): this;
	
	/**
	 * Sets a custom FindMany args type (e.g., from prisma-nest-graphql).
	 * This replaces the default take/skip pagination with full Prisma-style args including
	 * cursor, orderBy, distinct, etc.
	 *
	 * @template FindManyArgs The type of the custom find many args
	 * @param findManyArgsType The custom FindMany args class
	 * @returns The configuration builder for chaining
	 * @example
	 * ```typescript
	 * // Using prisma-nest-graphql generated FindManyArgs
	 * .withFindManyArgs(FindManyUserArgs)
	 * ```
	 */
	withFindManyArgs<FindManyArgs>(findManyArgsType: Type<FindManyArgs>): this;
}

/**
 * Main configuration builder for CRUD modules with a fluent API.
 * Inherits common functionality from BaseCrudModuleConfig and adds custom resolver support.
 *
 * @template Item The entity type
 * @template CreateInput The input type for create operations
 * @template UpdateInput The input type for update operations
 * @template UpdateManyInput The input type for update many operations
 * @template WhereInput The input type for query filters
 */
export declare class CrudModuleConfig<
	Item,
	CreateInput,
	UpdateInput,
	UpdateManyInput,
	WhereInput
> extends BaseCrudModuleConfig<Item> {
	/**
	 * Registers a custom resolver class for this entity.
	 * This method changes the configuration API to allow adding specific resolver types.
	 *
	 * @template TResolver The type of the resolver class
	 * @param resolverClass The resolver class that implements custom resolvers
	 * @returns A CustomResolverConfig instance for chaining specialized resolver methods
	 */
	withCustomResolver<TResolver extends object>(
		resolverClass: Type<TResolver>
	): CustomResolverConfig<Item, CreateInput, UpdateInput, UpdateManyInput, WhereInput, TResolver>;
}

/**
 * Configuration class for custom resolvers.
 * Appears after withCustomResolver is called and provides methods for mapping resolver methods.
 *
 * @template Item The entity type
 * @template CreateInput The input type for create operations
 * @template UpdateInput The input type for update operations
 * @template UpdateManyInput The input type for update many operations
 * @template WhereInput The input type for query filters
 * @template TResolver The type of the resolver class
 */
export declare class CustomResolverConfig<
	Item,
	CreateInput,
	UpdateInput,
	UpdateManyInput,
	WhereInput,
	TResolver extends object
> extends BaseCrudModuleConfig<Item> {
	/**
	 * Add a custom query to the GraphQL schema.
	 * Maps a method on the resolver class to a GraphQL query.
	 *
	 * @template M Method name in the resolver class
	 * @param config Configuration for the query
	 * @returns The configuration builder for chaining
	 */
	addQuery<
		M extends keyof TResolver,
		// Ensure M is a method that returns a Promise
		_ extends TResolver[M] extends (...args: any[]) => Promise<any> ? true : never
	>(
		config: {
			name: string;
			description?: string;
			inputType: Type<ParametersOfMethod<TResolver, M>>;
			outputType: Getter<Type<Awaited<ReturnTypeOfMethod<TResolver, M>>>>;
			nullable?: boolean;
			methodName: M & string;
			permissions: Permission[];
		}
	): this;
	
	/**
	 * Add a custom mutation to the GraphQL schema.
	 * Maps a method on the resolver class to a GraphQL mutation.
	 *
	 * @template M Method name in the resolver class
	 * @param config Configuration for the mutation
	 * @returns The configuration builder for chaining
	 */
	addMutation<
		M extends keyof TResolver,
		// Ensure M is a method that returns a Promise
		_ extends TResolver[M] extends (...args: any[]) => Promise<any> ? true : never
	>(
		config: {
			name: string;
			description?: string;
			inputType: Type<ParametersOfMethod<TResolver, M>>;
			outputType: Getter<Type<Awaited<ReturnTypeOfMethod<TResolver, M>>>>;
			nullable?: boolean;
			methodName: M & string;
			permissions: Permission[];
		}
	): this;
	
	/**
	 * Add a field resolver to a type in the GraphQL schema.
	 * Maps a method on the resolver class to a GraphQL field resolver.
	 *
	 * @template M Method name in the resolver class
	 * @param config Configuration for the field resolver
	 * @returns The configuration builder for chaining
	 */
	addResolveField<
		M extends keyof TResolver,
		// Ensure M is a method that returns a Promise
		_ extends TResolver[M] extends (...args: any[]) => Promise<any> ? true : never
	>(
		config: {
			name: string;
			description?: string;
			inputType: Type<ParametersOfResolveMethod<Item, TResolver, M>>;
			outputType: Getter<Type<Awaited<ReturnTypeOfMethod<TResolver, M>>>>;
			nullable?: boolean;
			methodName: M & string;
			permissions: Permission[];
			resolveField: string;
		}
	): this;
	
	/**
	 * Go back to the main config builder.
	 * Provides a way to return to the main CrudModuleConfig after adding custom resolvers.
	 *
	 * @returns The main CrudModuleConfig instance
	 */
	and(): CrudModuleConfig<Item, CreateInput, UpdateInput, UpdateManyInput, WhereInput>;
}

/**
 * Factory class for creating and registering all CRUD modules based on provided configurations.
 * This is the main entry point for integrating the library into a NestJS application.
 *
 * @example
 * ```typescript
 * // In your NestJS module (e.g., app.module.ts)
 * @Module({
 * imports: [
 *   // 1. Specify global providers (DataProvider, FieldSelectionProvider)
 *   CrudModulesFactory
 *     .using(MyPrismaDataProvider, MyPrismaFieldSelectionProvider)
 *     // 2. Provide configurations for all desired entities
 *     .forRoot([
 *       // Configure the 'User' entity
 *       CrudModulesFactory
 *         .forEntity(User)
 *         .withConfig({
 *           modelName: 'user',
 *           createInput: UserCreateInput,
 *           updateInput: UserUpdateInput,
 *           updateManyInput: UserUpdateManyInput,
 *           whereInput: UserWhereInput,
 *         })
 *         // Use custom FindMany args from prisma-nest-graphql
 *         .withFindManyArgs(FindManyUserArgs)
 *         // Add one-to-many relation
 *         .addRelation<Post, PostWhereInput>({
 *           fieldName: 'posts',
 *           targetModel: 'post',
 *           targetType: Post,
 *           targetWhereInput: PostWhereInput,
 *           whereNullable: true,
 *           relationField: 'authorId'
 *         })
 *         // Add custom resolvers
 *         .withCustomResolver(UserCustomResolver)
 *           .addQuery({
 *             name: 'findUserByEmail',
 *             methodName: 'findByEmail',
 *             permissions: [Permission.READ_USERS]
 *           })
 *           .addMutation({
 *             name: 'changeUserPassword',
 *             methodName: 'changePassword',
 *             permissions: [Permission.UPDATE_USERS]
 *           })
 *           .and()
 *         // Add subscription support
 *         .withSubscription({
 *           filter: UserSubscriptionFilterInput,
 *           resolver: CustomUserSubscriptionResolver
 *         }),
 *     ]),
 * ]})
 * export class AppModule {}
 * ```
 */
export declare class CrudModulesFactory {
	/**
	 * Starts the configuration process for a specific entity type.
	 * Call this first for each entity you want to manage.
	 * @param entity The class representing the entity type (e.g., `User`).
	 * @returns An object with the `withConfig` method to provide core CRUD configuration.
	 * @template Item The entity type.
	 */
	static forEntity<Item>(entity: Type<Item>): {
		/**
		 * Provides the basic configuration necessary for generating CRUD operations
		 * (queries, mutations) for the specified entity.
		 * @param config An object containing the logical model name (e.g., Prisma model name)
		 * and the classes representing the GraphQL input types for create, update, updateMany, and where operations.
		 * @returns A `CrudModuleConfig` instance allowing further configuration chaining (e.g., adding relations).
		 */
		withConfig<CreateInput, UpdateInput, UpdateManyInput, WhereInput>(config: {
			modelName: string;
			createInput: Type<CreateInput>;
			updateInput: Type<UpdateInput>;
			updateManyInput: Type<UpdateManyInput>;
			whereInput: Type<WhereInput>;
		}): CrudModuleConfig<Item, CreateInput, UpdateInput, UpdateManyInput, WhereInput>;
	};
	
	/**
	 * Specifies the global `DataProvider` and `FieldSelectionProvider` implementations
	 * that will be used by all generated CRUD modules. These providers handle the actual
	 * database interaction and field selection logic.
	 * @param dataProvider The class implementing the `DataProvider` interface.
	 * @param fieldSelectionProvider The class implementing the `FieldSelectionProvider` interface.
	 * @returns An object with the `forRoot` method to finalize module creation.
	 */
	static using(dataProvider: Type<DataProvider>, fieldSelectionProvider: Type<FieldSelectionProvider>): {
		/**
		 * Creates the dynamic NestJS module containing all configured CRUD modules,
		 * relation resolvers, subscription handlers, and the specified global providers.
		 * This resulting module should be included in the `imports` array of your root AppModule
		 * or a relevant feature module.
		 * @param configBuilders An array of `CrudModuleConfig` instances, each fully configured
		 * using the `forEntity(...).withConfig(...).addRelation(...)` chain.
		 * @returns The configured `DynamicModule` ready to be imported by NestJS.
		 */
		forRoot(configBuilders: BaseCrudModuleConfig<any>[]): DynamicModule;
	};
}

/**
 * A default implementation of `FieldSelectionProvider` that uses the `@paljs/plugins`
 * library to parse GraphQL query info (`GraphQLResolveInfo`) and generate a
 * Prisma-compatible `select` object. Useful when using Prisma as the backend.
 */
export declare class PrismaFieldSelectionProvider implements FieldSelectionProvider {
	/**
	 * Parses GraphQL info using `@paljs/plugins` PrismaSelect.
	 * @param info The `GraphQLResolveInfo` object provided by the GraphQL execution engine.
	 * @returns A Prisma-compatible `select` object structure usable in `prismaClient.model.find*` calls.
	 * @template EntityType The entity type being queried.
	 */
	parseSelection<EntityType>(info: GraphQLResolveInfo): FieldSelectionResult<EntityType>;
}

/**
 * A factory function that generates a NestJS injectable class implementing the `DataProvider`
 * interface specifically for use with Prisma. It handles the necessary dependency injection
 * of the `PrismaClient`.
 * @param Service The constructor of your `PrismaClient` class (or an extended subclass).
 * This allows the generated provider to obtain an instance of the Prisma client via NestJS DI.
 * @returns A NestJS injectable class (`Type<DataProvider>`) that implements the `DataProvider`
 * interface using the provided `PrismaClient` service for database operations.
 * @example
 * ```typescript
 * // In CrudModulesFactory setup:
 * CrudModulesFactory.using(
 *  PrismaDataProvider(PrismaClient), // Pass your PrismaClient class here
 *  PrismaFieldSelectionProvider
 * ).forRoot(...)
 * ```
 */
export declare function PrismaDataProvider(Service: Type<PrismaClient>): Type<DataProvider>;

/**
 * A decorator function that marks a method's parameter as the current `PubSub` instance.
 * This is useful for injecting the `PubSub` instance into your subscription resolvers
 * or other classes that need to publish events.
 * @returns A parameter decorator that can be applied to method parameters.
 * @example
 * ```typescript
 * import { PubSub } from 'graphql-subscriptions';
 * import { CurrentPubSub } from '@eleven-am/nestjs-graphql-crud';
 *
 * class MySubscriptionResolver {
 *   constructor(@CurrentPubSub() private pubSub: PubSub) {}
 * }
 * ```
 * This decorator will inject the current `PubSub` instance into the constructor of your class.
 * You can then use this instance to publish events to subscribers.
 */
export declare function CurrentPubSub(): ParameterDecorator;

/**
 * A factory function that creates a `FindManyContract` type for a specific entity type.
 * This is useful for defining the structure of the input arguments for the `findMany`
 * method in your data provider.
 * @param whereInput The type of the where input for filtering results.
 * @param modelName The logical name or identifier of the data model (e.g., Prisma model name).
 * @returns A `Type<FindManyContract<T>>` representing the structure of the find many contract.
 */
export declare function createFindMany<T> (whereInput: Type<T>, modelName: string): Type<FindManyContract<T>>;