@smithy/types/dist-types/middleware.d.ts

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import type { AuthScheme, HttpAuthDefinition } from "./auth/auth";
import type { SelectedHttpAuthScheme } from "./auth/HttpAuthScheme";
import type { Command } from "./command";
import type { EndpointV2 } from "./endpoint";
import type { SmithyFeatures } from "./feature-ids";
import type { Logger } from "./logger";
import type { UserAgent } from "./util";
/**
 * @public
 */
export interface InitializeHandlerArguments<Input extends object> {
    /**
     * User input to a command. Reflects the userland representation of the
     * union of data types the command can effectively handle.
     */
    input: Input;
}
/**
 * @public
 */
export interface InitializeHandlerOutput<Output extends object> extends DeserializeHandlerOutput<Output> {
    output: Output;
}
/**
 * @public
 */
export interface SerializeHandlerArguments<Input extends object> extends InitializeHandlerArguments<Input> {
    /**
     * The user input serialized as a request object. The request object is unknown,
     * so you cannot modify it directly. When work with request, you need to guard its
     * type to e.g. HttpRequest with 'instanceof' operand
     *
     * During the build phase of the execution of a middleware stack, a built
     * request may or may not be available.
     */
    request?: unknown;
}
/**
 * @public
 */
export interface SerializeHandlerOutput<Output extends object> extends InitializeHandlerOutput<Output> {
}
/**
 * @public
 */
export interface BuildHandlerArguments<Input extends object> extends FinalizeHandlerArguments<Input> {
}
/**
 * @public
 */
export interface BuildHandlerOutput<Output extends object> extends InitializeHandlerOutput<Output> {
}
/**
 * @public
 */
export interface FinalizeHandlerArguments<Input extends object> extends SerializeHandlerArguments<Input> {
    /**
     * The user input serialized as a request.
     */
    request: unknown;
}
/**
 * @public
 */
export interface FinalizeHandlerOutput<Output extends object> extends InitializeHandlerOutput<Output> {
}
/**
 * @public
 */
export interface DeserializeHandlerArguments<Input extends object> extends FinalizeHandlerArguments<Input> {
}
/**
 * @public
 */
export interface DeserializeHandlerOutput<Output extends object> {
    /**
     * The raw response object from runtime is deserialized to structured output object.
     * The response object is unknown so you cannot modify it directly. When work with
     * response, you need to guard its type to e.g. HttpResponse with 'instanceof' operand.
     *
     * During the deserialize phase of the execution of a middleware stack, a deserialized
     * response may or may not be available
     */
    response: unknown;
    output?: Output;
}
/**
 * @public
 */
export interface InitializeHandler<Input extends object, Output extends object> {
    /**
     * Asynchronously converts an input object into an output object.
     *
     * @param args - An object containing a input to the command as well as any
     *              associated or previously generated execution artifacts.
     */
    (args: InitializeHandlerArguments<Input>): Promise<InitializeHandlerOutput<Output>>;
}
/**
 * @public
 */
export type Handler<Input extends object, Output extends object> = InitializeHandler<Input, Output>;
/**
 * @public
 */
export interface SerializeHandler<Input extends object, Output extends object> {
    /**
     * Asynchronously converts an input object into an output object.
     *
     * @param args - An object containing a input to the command as well as any
     *              associated or previously generated execution artifacts.
     */
    (args: SerializeHandlerArguments<Input>): Promise<SerializeHandlerOutput<Output>>;
}
/**
 * @public
 */
export interface FinalizeHandler<Input extends object, Output extends object> {
    /**
     * Asynchronously converts an input object into an output object.
     *
     * @param args - An object containing a input to the command as well as any
     *              associated or previously generated execution artifacts.
     */
    (args: FinalizeHandlerArguments<Input>): Promise<FinalizeHandlerOutput<Output>>;
}
/**
 * @public
 */
export interface BuildHandler<Input extends object, Output extends object> {
    (args: BuildHandlerArguments<Input>): Promise<BuildHandlerOutput<Output>>;
}
/**
 * @public
 */
export interface DeserializeHandler<Input extends object, Output extends object> {
    (args: DeserializeHandlerArguments<Input>): Promise<DeserializeHandlerOutput<Output>>;
}
/**
 * @public
 *
 * A factory function that creates functions implementing the `Handler`
 * interface.
 */
export interface InitializeMiddleware<Input extends object, Output extends object> {
    /**
     * @param next - The handler to invoke after this middleware has operated on
     * the user input and before this middleware operates on the output.
     *
     * @param context - Invariant data and functions for use by the handler.
     */
    (next: InitializeHandler<Input, Output>, context: HandlerExecutionContext): InitializeHandler<Input, Output>;
}
/**
 * @public
 *
 * A factory function that creates functions implementing the `BuildHandler`
 * interface.
 */
export interface SerializeMiddleware<Input extends object, Output extends object> {
    /**
     * @param next - The handler to invoke after this middleware has operated on
     * the user input and before this middleware operates on the output.
     *
     * @param context - Invariant data and functions for use by the handler.
     */
    (next: SerializeHandler<Input, Output>, context: HandlerExecutionContext): SerializeHandler<Input, Output>;
}
/**
 * @public
 *
 * A factory function that creates functions implementing the `FinalizeHandler`
 * interface.
 */
export interface FinalizeRequestMiddleware<Input extends object, Output extends object> {
    /**
     * @param next - The handler to invoke after this middleware has operated on
     * the user input and before this middleware operates on the output.
     *
     * @param context - Invariant data and functions for use by the handler.
     */
    (next: FinalizeHandler<Input, Output>, context: HandlerExecutionContext): FinalizeHandler<Input, Output>;
}
/**
 * @public
 */
export interface BuildMiddleware<Input extends object, Output extends object> {
    (next: BuildHandler<Input, Output>, context: HandlerExecutionContext): BuildHandler<Input, Output>;
}
/**
 * @public
 */
export interface DeserializeMiddleware<Input extends object, Output extends object> {
    (next: DeserializeHandler<Input, Output>, context: HandlerExecutionContext): DeserializeHandler<Input, Output>;
}
/**
 * @public
 */
export type MiddlewareType<Input extends object, Output extends object> = InitializeMiddleware<Input, Output> | SerializeMiddleware<Input, Output> | BuildMiddleware<Input, Output> | FinalizeRequestMiddleware<Input, Output> | DeserializeMiddleware<Input, Output>;
/**
 * @public
 *
 * A factory function that creates the terminal handler atop which a middleware
 * stack sits.
 */
export interface Terminalware {
    <Input extends object, Output extends object>(context: HandlerExecutionContext): DeserializeHandler<Input, Output>;
}
/**
 * @public
 */
export type Step = "initialize" | "serialize" | "build" | "finalizeRequest" | "deserialize";
/**
 * @public
 */
export type Priority = "high" | "normal" | "low";
/**
 * @public
 */
export interface HandlerOptions {
    /**
     * Handlers are ordered using a "step" that describes the stage of command
     * execution at which the handler will be executed. The available steps are:
     *
     * - initialize: The input is being prepared. Examples of typical
     *      initialization tasks include injecting default options computing
     *      derived parameters.
     * - serialize: The input is complete and ready to be serialized. Examples
     *      of typical serialization tasks include input validation and building
     *      an HTTP request from user input.
     * - build: The input has been serialized into an HTTP request, but that
     *      request may require further modification. Any request alterations
     *      will be applied to all retries. Examples of typical build tasks
     *      include injecting HTTP headers that describe a stable aspect of the
     *      request, such as `Content-Length` or a body checksum.
     * - finalizeRequest: The request is being prepared to be sent over the wire. The
     *      request in this stage should already be semantically complete and
     *      should therefore only be altered as match the recipient's
     *      expectations. Examples of typical finalization tasks include request
     *      signing and injecting hop-by-hop headers.
     * - deserialize: The response has arrived, the middleware here will deserialize
     *      the raw response object to structured response
     *
     *      Unlike initialization and build handlers, which are executed once
     *      per operation execution, finalization and deserialize handlers will be
     *      executed foreach HTTP request sent.
     *
     * @defaultValue 'initialize'
     */
    step?: Step;
    /**
     * A list of strings to any that identify the general purpose or important
     * characteristics of a given handler.
     */
    tags?: Array<string>;
    /**
     * A unique name to refer to a middleware
     */
    name?: string;
    /**
     * @internal
     * Aliases allows for middleware to be found by multiple names besides {@link HandlerOptions.name}.
     * This allows for references to replaced middleware to continue working, e.g. replacing
     * multiple auth-specific middleware with a single generic auth middleware.
     */
    aliases?: Array<string>;
    /**
     * A flag to override the existing middleware with the same name. Without
     * setting it, adding middleware with duplicated name will throw an exception.
     * @internal
     */
    override?: boolean;
}
/**
 * @public
 */
export interface AbsoluteLocation {
    /**
     * By default middleware will be added to individual step in un-guaranteed order.
     * In the case that
     *
     * @defaultValue 'normal'
     */
    priority?: Priority;
}
/**
 * @public
 */
export type Relation = "before" | "after";
/**
 * @public
 */
export interface RelativeLocation {
    /**
     * Specify the relation to be before or after a know middleware.
     */
    relation: Relation;
    /**
     * A known middleware name to indicate inserting middleware's location.
     */
    toMiddleware: string;
}
/**
 * @public
 */
export type RelativeMiddlewareOptions = RelativeLocation & Omit<HandlerOptions, "step">;
/**
 * @public
 */
export interface InitializeHandlerOptions extends HandlerOptions {
    step?: "initialize";
}
/**
 * @public
 */
export interface SerializeHandlerOptions extends HandlerOptions {
    step: "serialize";
}
/**
 * @public
 */
export interface BuildHandlerOptions extends HandlerOptions {
    step: "build";
}
/**
 * @public
 */
export interface FinalizeRequestHandlerOptions extends HandlerOptions {
    step: "finalizeRequest";
}
/**
 * @public
 */
export interface DeserializeHandlerOptions extends HandlerOptions {
    step: "deserialize";
}
/**
 * @public
 *
 * A stack storing middleware. It can be resolved into a handler. It supports 2
 * approaches for adding middleware:
 * 1. Adding middleware to specific step with `add()`. The order of middleware
 *    added into same step is determined by order of adding them. If one middleware
 *    needs to be executed at the front of the step or at the end of step, set
 *    `priority` options to `high` or `low`.
 * 2. Adding middleware to location relative to known middleware with `addRelativeTo()`.
 *    This is useful when given middleware must be executed before or after specific
 *    middleware(`toMiddleware`). You can add a middleware relatively to another
 *    middleware which also added relatively. But eventually, this relative middleware
 *    chain **must** be 'anchored' by a middleware that added using `add()` API
 *    with absolute `step` and `priority`. This mothod will throw if specified
 *    `toMiddleware` is not found.
 */
export interface MiddlewareStack<Input extends object, Output extends object> extends Pluggable<Input, Output> {
    /**
     * Add middleware to the stack to be executed during the "initialize" step,
     * optionally specifying a priority, tags and name
     */
    add(middleware: InitializeMiddleware<Input, Output>, options?: InitializeHandlerOptions & AbsoluteLocation): void;
    /**
     * Add middleware to the stack to be executed during the "serialize" step,
     * optionally specifying a priority, tags and name
     */
    add(middleware: SerializeMiddleware<Input, Output>, options: SerializeHandlerOptions & AbsoluteLocation): void;
    /**
     * Add middleware to the stack to be executed during the "build" step,
     * optionally specifying a priority, tags and name
     */
    add(middleware: BuildMiddleware<Input, Output>, options: BuildHandlerOptions & AbsoluteLocation): void;
    /**
     * Add middleware to the stack to be executed during the "finalizeRequest" step,
     * optionally specifying a priority, tags and name
     */
    add(middleware: FinalizeRequestMiddleware<Input, Output>, options: FinalizeRequestHandlerOptions & AbsoluteLocation): void;
    /**
     * Add middleware to the stack to be executed during the "deserialize" step,
     * optionally specifying a priority, tags and name
     */
    add(middleware: DeserializeMiddleware<Input, Output>, options: DeserializeHandlerOptions & AbsoluteLocation): void;
    /**
     * Add middleware to a stack position before or after a known middleware，optionally
     * specifying name and tags.
     */
    addRelativeTo(middleware: MiddlewareType<Input, Output>, options: RelativeMiddlewareOptions): void;
    /**
     * Apply a customization function to mutate the middleware stack, often
     * used for customizations that requires mutating multiple middleware.
     */
    use(pluggable: Pluggable<Input, Output>): void;
    /**
     * Create a shallow clone of this stack. Step bindings and handler priorities
     * and tags are preserved in the copy.
     */
    clone(): MiddlewareStack<Input, Output>;
    /**
     * Removes middleware from the stack.
     *
     * If a string is provided, it will be treated as middleware name. If a middleware
     * is inserted with the given name, it will be removed.
     *
     * If a middleware class is provided, all usages thereof will be removed.
     */
    remove(toRemove: MiddlewareType<Input, Output> | string): boolean;
    /**
     * Removes middleware that contains given tag
     *
     * Multiple middleware will potentially be removed
     */
    removeByTag(toRemove: string): boolean;
    /**
     * Create a stack containing the middlewares in this stack as well as the
     * middlewares in the `from` stack. Neither source is modified, and step
     * bindings and handler priorities and tags are preserved in the copy.
     */
    concat<InputType extends Input, OutputType extends Output>(from: MiddlewareStack<InputType, OutputType>): MiddlewareStack<InputType, OutputType>;
    /**
     * Returns a list of the current order of middleware in the stack.
     * This does not execute the middleware functions, nor does it
     * provide a reference to the stack itself.
     */
    identify(): string[];
    /**
     * @internal
     *
     * When an operation is called using this stack,
     * it will log its list of middleware to the console using
     * the identify function.
     *
     * @param toggle - set whether to log on resolve.
     *                 If no argument given, returns the current value.
     */
    identifyOnResolve(toggle?: boolean): boolean;
    /**
     * Builds a single handler function from zero or more middleware classes and
     * a core handler. The core handler is meant to send command objects to AWS
     * services and return promises that will resolve with the operation result
     * or be rejected with an error.
     *
     * When a composed handler is invoked, the arguments will pass through all
     * middleware in a defined order, and the return from the innermost handler
     * will pass through all middleware in the reverse of that order.
     */
    resolve<InputType extends Input, OutputType extends Output>(handler: DeserializeHandler<InputType, OutputType>, context: HandlerExecutionContext): InitializeHandler<InputType, OutputType>;
}
/**
 * @internal
 */
export declare const SMITHY_CONTEXT_KEY = "__smithy_context";
/**
 * @public
 *
 * Data and helper objects that are not expected to change from one execution of
 * a composed handler to another.
 */
export interface HandlerExecutionContext {
    /**
     * A logger that may be invoked by any handler during execution of an
     * operation.
     */
    logger?: Logger;
    /**
     * Name of the service the operation is being sent to.
     */
    clientName?: string;
    /**
     * Name of the operation being executed.
     */
    commandName?: string;
    /**
     * Additional user agent that inferred by middleware. It can be used to save
     * the internal user agent sections without overriding the `customUserAgent`
     * config in clients.
     */
    userAgent?: UserAgent;
    /**
     * Resolved by the endpointMiddleware function of `@smithy/middleware-endpoint`
     * in the serialization stage.
     */
    endpointV2?: EndpointV2;
    /**
     * Set at the same time as endpointV2.
     */
    authSchemes?: AuthScheme[];
    /**
     * The current auth configuration that has been set by any auth middleware and
     * that will prevent from being set more than once.
     */
    currentAuthConfig?: HttpAuthDefinition;
    /**
     * @deprecated do not extend this field, it is a carryover from AWS SDKs.
     * Used by DynamoDbDocumentClient.
     */
    dynamoDbDocumentClientOptions?: Partial<{
        overrideInputFilterSensitiveLog(...args: any[]): string | void;
        overrideOutputFilterSensitiveLog(...args: any[]): string | void;
    }>;
    /**
     * @internal
     * Context for Smithy properties.
     */
    [SMITHY_CONTEXT_KEY]?: {
        service?: string;
        operation?: string;
        commandInstance?: Command<any, any, any, any, any>;
        selectedHttpAuthScheme?: SelectedHttpAuthScheme;
        features?: SmithyFeatures;
        /**
         * @deprecated
         * Do not assign arbitrary members to the Smithy Context,
         * fields should be explicitly declared here to avoid collisions.
         */
        [key: string]: unknown;
    };
    /**
     * @deprecated
     * Do not assign arbitrary members to the context, since
     * they can interfere with existing functionality.
     *
     * Additional members should instead be declared on the SMITHY_CONTEXT_KEY
     * or other reserved keys.
     */
    [key: string]: any;
}
/**
 * @public
 */
export interface Pluggable<Input extends object, Output extends object> {
    /**
     * A function that mutate the passed in middleware stack. Functions implementing
     * this interface can add, remove, modify existing middleware stack from clients
     * or commands
     */
    applyToStack: (stack: MiddlewareStack<Input, Output>) => void;
}