@aws-amplify/core
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Core category of aws-amplify
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TypeScript
import { ServiceClientOptions } from '../types/aws';
import { Endpoint, TransferHandler } from '../types/core';
import { HttpRequest, HttpResponse } from '../types/http';
/**
* Compose a service API handler that accepts input as defined shape and responds conforming to defined output shape.
* A service API handler is composed with:
* * A transfer handler
* * A serializer function
* * A deserializer function
* * A default config object
*
* The returned service API handler, when called, will trigger the following workflow:
* 1. When calling the service API handler function, the default config object is merged into the input config
* object to assign the default values of some omitted configs, resulting to a resolved config object.
* 2. The `endpointResolver` function from the default config object will be invoked with the resolved config object and
* API input object resulting to an endpoint instance.
* 3. The serializer function is invoked with API input object and the endpoint instance resulting to an HTTP request
* instance.
* 4. The HTTP request instance and the resolved config object is passed to the transfer handler function.
* 5. The transfer handler function resolves to an HTTP response instance(can be either successful or failed status code).
* 6. The deserializer function is invoked with the HTTP response instance resulting to the API output object, and
* return to the caller.
*
*
* @param transferHandler Async function for dispatching HTTP requests and returning HTTP response.
* @param serializer Async function for converting object in defined input shape into HTTP request targeting a given
* endpoint.
* @param deserializer Async function for converting HTTP response into output object in defined output shape, or error
* shape.
* @param defaultConfig object containing default options to be consumed by transfer handler, serializer and
* deserializer.
* @returns a async service API handler function that accepts a config object and input object in defined shape, returns
* an output object in defined shape. It may also throw error instance in defined shape in deserializer. The config
* object type is composed with options type of transferHandler, endpointResolver function as well as endpointResolver
* function's input options type, region string. The config object property will be marked as optional if it's also
* defined in defaultConfig.
*
* @internal
*/
export declare const composeServiceApi: <TransferHandlerOptions, Input, Output, DefaultConfig>(transferHandler: TransferHandler<HttpRequest, HttpResponse, TransferHandlerOptions>, serializer: (input: Input, endpoint: Endpoint) => Promise<HttpRequest> | HttpRequest, deserializer: (output: HttpResponse) => Promise<Output>, defaultConfig: Partial<DefaultConfig>) => (config: OptionalizeKey<TransferHandlerOptions & ServiceClientOptions & InferEndpointResolverOptionType<DefaultConfig> & Partial<DefaultConfig>, DefaultConfig>, input: Input) => Promise<Output>;
/**
* Type helper to make a given key optional in a given type. For all the keys in the `InputDefaultsType`, if its value
* is assignable to the value of the same key in `InputType`, we will mark the key in `InputType` is optional. If
* the `InputType` and `InputDefaultsType` has the same key but un-assignable types, the resulting type is `never` to
* trigger a type error down the line.
*
* @example
* type InputType = {
* a: string;
* b: number;
* c: string;
* };
* type InputDefaultsType = {
* a: string;
* b: number;
* };
* type OutputType = OptionalizeKey<InputType, InputDefaultsType>;
* OutputType equals to:
* {
* a?: string;
* b?: number;
* c: string;
* }
*/
type OptionalizeKey<InputType, InputDefaultsType> = {
[KeyWithDefaultValue in keyof InputDefaultsType]?: KeyWithDefaultValue extends keyof InputType ? InputType[KeyWithDefaultValue] : never;
} & {
[KeyWithoutDefaultValue in keyof Omit<InputType, keyof InputDefaultsType>]: InputType[KeyWithoutDefaultValue];
};
type InferEndpointResolverOptionType<T> = T extends {
endpointResolver(options: infer EndpointOptions, input: any): any;
} ? EndpointOptions : never;
export {};