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restapi-typescript-decorators

Inspired by retrofit (created by Square), my goal for this project is to create a single rest client for both front end JS as well as back end node JS using just decorators (also known as annotations in the Java’s world). These decorators are used to make REST API calls simpler and more declarative

Another inspiration is to create a unified Rest Client library that works across the stack. In this case, to support node js and frontend code in a single code base. The goal is to create a single decorator for both node js and frontend.

Features

TODO’s

  • Supports proper serialization of request based on headers accept
  • Add a new class decorator and supports default custom properties and baseUrl at a class / repo level
  • Deploy to npm modules instead of using github
  • Supports to instantiate multiple classes, useful when we need to support Api with different tokens.
  • Allow calling instance methods within requestTransform and responseTransform
  • Added Prettier for code format
  • Clean up the types and use proper types from node-fetch instead of using our own
  • Integrate with CI pipeline to build stuffs and run tests automatically
  • Make CI pipeline publish to npm registry
  • Uses ApiResponse for return type instead of any
  • Consolidate enum / string types for HttpVerb and AuthType
  • Allows class level @RestClient override for requesgt_transform and responseTransform
  • Support POST binary file to API
  • Have an example repo for backend NodeJS code. Refer to the demos at frontend example repo or backend node js example repo
  • Have an example repo for frontend code. Refer to the front end example repo
  • Cleanup / Refactor and Export typescript types
  • Enforce noImplicitAny
  • Throw exception when missing key params
  • Make sure the retry logics respect Server side retry-after response header.
  • Add support for custom retry, aka has it more dynamic as a custom function…
  • Add API debounce actions
  • Add support for custom fast-xml-parser options

How to use?

You can also checkout the sample repos that has typescript and other things setup:

Live Demo

You can test a live demo of the frontend code at https://synle.github.io/restapi-typescript-decorators-front-end-example/dist/

Install it

install from npm

npm i --save restapi-typescript-decorators@^6

Make sure you have the typescript and decorator enabled in your tsconfig.json

Simple Code Example

Most of these examples return ApiResponse<any> for simplicity. You can use the library to cast the response object in a custom format. Refer to the bottom section of this guide for how to do type cast your requests and responses.

import the classes

import {
  ApiResponse,
  CredentialProperty,
  FileUploadBody,
  FormDataBody,
  PathParam,
  QueryParamProperty,
  QueryParams,
  RequestProperty,
  RequestBody,
  RestApi,
  RestClient,
} from 'restapi-typescript-decorators';

Public (non authenticated) API Store

Below is an example on the definition for public API data store.

import {
  RestClient,
  RestApi,
  RequestProperty,
  RequestBody,
  PathParam,
  QueryParamProperty,
  QueryParams,
  FormDataBody,
  FileUploadBody,
  ApiResponse,
} from 'restapi-typescript-decorators';

// first define your request and response body
export interface HttpBinRequest {
  [propName: string]: any;
}
export interface HttpBinResponse {
  args?: {
    [propName: string]: any;
  };
  headers?: {
    [propName: string]: any;
  };
  origin?: string;
  url?: string;
  data?: {
    [propName: string]: any;
  };
  json?:
    | string
    | {
        [propName: string]: any;
      };
  form?: {
    [propName: string]: any;
  };
  [propName: string]: any;
}

@RestClient({
  baseUrl: 'https://httpbin.org',
})
export class PublicApiDataStore {
  /**
   * do get with absolute URL. This example will use
   * url defined here instead of appended it to the baseUrl
   */
  @RestApi('https://httpbin.org/get')
  doGetWithAbsoluteUrl(): ApiResponse<HttpBinResponse> {}

  /**
   * do get with query params (as a hash of queryParamKey => queryParamValue)
   * @param _queryParams
   */
  @RestApi('/get')
  doGetWithQueryParams(@QueryParams _queryParams: HttpBinRequest): ApiResponse<HttpBinResponse> {}

  /**
   * do get with query params (as a single parameter). This example will construct url as
   * /get?keyword=<_keyword>&_pageSize=<number>
   * @param _keyword
   * @param _pageSize
   */
  @RestApi('/get')
  doGetWithSingleQueryParam(
    @QueryParamProperty('keyword') _keyword: string = '',
    @QueryParamProperty('pageSize') _pageSize: number = 100,
  ): ApiResponse<HttpBinResponse> {}

  /**
   * do get with a combination of both single query param, and query params hash. In this
   * example, we will combine the two query params with single query param has higher
   * precedence than query params hash
   * @param _query
   * @param _pageSize
   */
  @RestApi('/get')
  doGetWithQueryParamsCombo(
    @QueryParams _query: HttpBinRequest,
    @QueryParamProperty('pageSize') _pageSize: number = 100,
  ): ApiResponse<HttpBinResponse> {}

  /**
   * do get with a path param which will replace
   * `{recordId}` fragment in the URL with value you invoke the method with
   * @param _recordId value to replace {recordId} URL fragment
   */
  @RestApi('/anything/{recordId}')
  doGetWithPathParams(@PathParam('recordId') _recordId: string): ApiResponse<HttpBinResponse> {}

  /**
   * do get with path params and query params
   * @param _messageId value to replace {messageId} URL fragment
   * @param _queryParams query params
   */
  @RestApi('/anything/{messageId}')
  doGetWithPathParamsAndQueryParams(
    @PathParam('messageId') _messageId: string,
    @QueryParams _queryParams: HttpBinRequest,
  ): ApiResponse<HttpBinResponse> {}

  /**
   * do get with a timeout. The REST call will be aborted after
   * 3 seconds.
   */
  @RestApi('/delay/10', {
    timeout: 3000,
  })
  doGetWithTimeout(): ApiResponse<HttpBinResponse> {}

  /**
   * do get with an Erroneous API. The backend of this API will
   * always return 405 error
   */
  @RestApi('/status/405')
  doErroneousAPI(): ApiResponse<HttpBinResponse> {}

  /**
   * do get with custom encoding from the backend API.
   * @param _encoding
   */
  @RestApi('/{encodingToUse}')
  doGetWithResponseEncoding(
    @PathParam('encodingToUse') _encoding: 'brotli' | 'gzip' | 'deflate',
  ): ApiResponse<HttpBinResponse> {}

  /**
   * do get with XML Response. This method will parse the XML responses into
   * JSON objects
   */
  @RestApi('/xml', {
    headers: {
      Accept: 'application/xml',
    },
  })
  doGetWithXmlResponse(): ApiResponse<HttpBinResponse> {}

  /**
   * do get call with Plain Text Response. This method will simply return the
   * Plain Text response from the back end API.
   */
  @RestApi('/robots.txt', {
    headers: {
      Accept: 'text/plain',
    },
  })
  doGetWithPlainTextResponse(): ApiResponse<string> {}

  /**
   * do post JSON request body with  @RequestBody (as a hash)
   * @param _body
   */
  @RestApi('/post', {
    method: 'POST',
  })
  doPostWithJsonBodyHash(@RequestBody _body: HttpBinRequest): ApiResponse<HttpBinResponse> {}

  /**
   * do post JSON request body with  @RequestBody (as a hash)
   * @param _body
   */
  @RestApi('/post', {
    method: 'POST',
  })
  doPostWithSingleValuesJsonBody(
    @RequestProperty('firstName') _firstName: string,
    @RequestProperty('lastName') _lastName: string,
  ): ApiResponse<HttpBinResponse> {}

  /**
   * do post with a combination of both single request property, and request body hash. In this
   * example, we will combine the two together with single request property has higher
   * precedence than query params hash
   *
   * @param _body
   * @param _userId
   */
  @RestApi('/post', {
    method: 'POST',
  })
  doPostWithJsonBodyMixture(
    @RequestBody _body: HttpBinRequest,
    @RequestProperty('userId') _userId: string,
  ): ApiResponse<HttpBinResponse> {}

  /**
   * do post with URL encoded form request body
   * @param _body
   */
  @RestApi('/post', {
    method: 'POST',
    headers: {
      'Content-Type': 'application/x-www-form-urlencoded',
    },
  })
  doPostWithEncodedFormData(@RequestBody _body: HttpBinRequest): ApiResponse<HttpBinResponse> {}

  /**
   * do post with formData
   * @param _unitPrice
   * @param _qty
   */
  @RestApi('/anything', {
    method: 'POST',
  })
  doPostWithFormBodyData(
    @FormDataBody('unitPrice') _unitPrice: number,
    @FormDataBody('quantity') _qty: number,
  ): ApiResponse<HttpBinResponse> {}

  /**
   * do post to upload the file via input named `mySms` with formData
   * @param _mySmsContent
   */
  @RestApi('/anything', {
    method: 'POST',
  })
  doUploadFileWithFormBodyData(
    @FormDataBody('mySms') _mySmsContent: HttpBinRequest,
  ): ApiResponse<HttpBinResponse> {}

  /**
   * do post to upload the file as a single stream
   * @param _fileToUpload
   */
  @RestApi('/post', {
    method: 'POST',
  })
  doUploadFileWithStreamRequest(@FileUploadBody _fileToUpload: any): ApiResponse<HttpBinResponse> {}
}

Then instantiate it as

import { PublicApiDataStore } from './PublicApiDataStore';
const myApiInstance = new PublicApiDataStore();

Use it You can use the response in a few ways.

Option 1 (preferred): with if check

const apiResponse = myApiInstance.doGetWithQueryParams({a: 1, b: 2});
if(apiResponse){
  apiResponse.result.then(
    resp => {
      // do something with your response
    }
  );
}

Option 2: no if check with await and async

async function doWorkFunc(){
  const apiResponse = myApiInstance.doGetWithQueryParams({a: 1, b: 2});
  if(apiResponse){
    try{
      const resp = await apiResponse.result;
      // do something with your response
    } catch(e){
      // api error, do some handler
    }
  }
}

Private (authenticated with Bearer Token) API Store

Below is an example on the definition for private API data store.

import {
  RestClient,
  RestApi,
  CredentialProperty,
  ApiResponse,
} from 'restapi-typescript-decorators';

// first define your request and response body
export interface HttpBinAuthResponse {
  authenticated: boolean;
  user?: string;
  token?: string;
  [propName: string]: any;
}

// Rest Client
@RestClient({
  baseUrl: 'https://httpbin.org',
  authType: 'Bearer',
})
export class PrivateBearerAuthApiDataStore {
  @CredentialProperty('AccessToken')
  accessToken: string;

  constructor(newAccessToken: string = '') {
    this.accessToken = newAccessToken;
  }

  @RestApi('/bearer', {
    method: 'GET',
  })
  doAuthenticatedCall(): ApiResponse<HttpBinAuthResponse> {}
}

Then instantiate it as

import { PrivateBearerAuthApiDataStore } from './PrivateBearerAuthApiDataStore';
const myApiInstance = new PrivateBearerAuthApiDataStore('good_username', 'good_password');

// ... refer to other section for how to execute the calls

Private (authenticated with username and password basic auth) API Store

import {
  RestClient,
  RestApi,
  CredentialProperty,
  ApiResponse,
} from 'restapi-typescript-decorators';

// first define your request and response body
export interface HttpBinAuthResponse {
  authenticated: boolean;
  user?: string;
  token?: string;
  [propName: string]: any;
}

// Rest Client
@RestClient({
  baseUrl: 'https://httpbin.org',
  authType: 'Basic',
})
export class PrivateBasicAuthApiDataStore {
  @CredentialProperty('Username')
  username: string;

  @CredentialProperty('Password')
  password: string;

  constructor(newUsername: string = '', newPassword: string = '') {
    this.username = newUsername;
    this.password = newPassword;
  }

  @RestApi('/basic-auth/good_username/good_password', {
    method: 'GET',
  })
  doAuthenticatedCall(): ApiResponse<HttpBinAuthResponse> {}
}

Then instantiate it as

import { PrivateBasicAuthApiDataStore } from './PrivateBasicAuthApiDataStore';
const myApiInstance = new PrivateBasicAuthApiDataStore('good_username', 'good_password');

// ... refer to other section for how to execute the calls

To execute the RestClient

const myApiInstance = new PrivateApiDataStore('<<some_strong_and_random_access_token>>');

const apiResponse = myApiInstance.doApiCallWithBearerToken();

if(apiResponse){
  apiResponse.result.then((resp) => {
    // ... do something with your response and status code ...
    console.log('ok', apiResponse.ok);
    console.log("url", apiResponse.url);
    console.log('status', apiResponse.status);
    console.log('resp', resp);
  });
}

To abort pending Rest calls

Sometimes you want to abort a pending Rest call. You can use apiResponse.abort(). Note that this action will also disable any attempt to retry the API for any pending instance method invokation. Say you are calling a fetch user with 5 retries, if you do abort. At that moment in time, the API will stop the pending API call and any retry.

// ... your construction code here ...

const apiResponse = myApiInstance.doApiCallWithBearerToken();

if (apiResponse) {
  apiResponse.result.then((resp) => {
    // ... api will be aborted, and this section will not be executed ...
  });

  apiResponse.abort();
}

Simple GET REST Calls with Query String

You can use either @QueryParams (as a hash) or @QueryParamProperty (as a single value for query string). This will send a GET request to the backend with query string attached. The library will handle url encoding for your data. So no need to encode it when using this API.

This example will pass a hash (queryStringKey => queryStringValue) into the query string

/**
* do get with query params (as a hash of queryParamKey => queryParamValue)
* @param _queryParams
*/
@RestApi('/get')
doGetWithQueryParams(@QueryParams _queryParams: HttpBinRequest): ApiResponse<HttpBinResponse> {}

This example will pass a single value into the query string

/**
* do get with query params (as a single parameter). This example will construct url as
* /get?keyword=<_keyword>&_pageSize=<number>
* @param _keyword
* @param _pageSize
*/
@RestApi('/get')
doGetWithSingleQueryParam(
  @QueryParam('keyword') _keyword: string = '',
  @QueryParam('pageSize') _pageSize: number = 100,
): ApiResponse<HttpBinResponse> {}
Notes on mixture of @QueryParams and @QueryParamProperty

When both @QueryParamProperty and @QueryParams are present in a single method, final result for query string will be merged with single value @QueryParamProperty has higher precedence than @QueryParams hash.

Below is an example of this:

/**
* do get with a combination of both single query param, and query params hash. In this
* example, we will combine the two query params with single query param has higher
* precedence than query params hash
* @param _query
* @param _pageSize
*/
@RestApi('/get')
doGetWithQueryParamsCombo(
  @QueryParams _query: HttpBinRequest,
  @QueryParamProperty('pageSize') _pageSize: number = 100,
): ApiResponse<HttpBinResponse> {}

Simple GET REST Calls with Path Param

@PathParams can be used in a class members (class attributes) or method parameters.

Below is an example of how path params can be used in a class member

@RestApi("/anything/{messageId}")
doGetWithPathParams(
  @PathParam("messageId") _targetMessageId: string
): ApiResponse<any> {}

The following code shows how path params can be used in class members and method parameters

@RestClient({
  baseUrl: 'https://httpbin.org/cookies/set/{cookieName}/{cookieValue}',
})
export class PathParamApiDataStore {
  @PathParam('cookieName')
  cookieName: string;

  constructor(newCookieName: string = '') {
    this.cookieName = newCookieName;
  }

  @RestApi()
  doGet(@PathParam('cookieValue') _newCookieValue: string): ApiResponse<HttpBinResponse> {}
}

Simple GET REST Calls with Path Param and Query String

@RestApi('/anything/{messageId}')
doGetWithPathParamsAndQueryParams(
  @PathParam('messageId') _targetMessageId: string,
  @QueryParams _queryParams: HttpBinRequest,
): ApiResponse<HttpBinResponse> {}

Simple POST Rest Calls with JSON Body

You can post JSON body with @RequestBody (as a hash) or @RequestProperty (as a single value).

Below is an example of how to POST JSON with @RequestBody (as a hash)

@RestApi('/post', {
  method: 'POST',
})
doPostWithJsonBody(@RequestBody _body: HttpBinRequest): ApiResponse<HttpBinResponse> {}

Below is an example of how to POST JSON with @RequestProperty (as a single value).

/**
* do post JSON request body with  @RequestBody (as a hash)
* @param _body
*/
@RestApi('/user_profile', {
  method: 'POST',
})
updateUserProfile(
  @RequestProperty('firstName') _firstName: string,
  @RequestProperty('lastName') _lastName: string,
): ApiResponse<HttpBinResponse> {}
Notes on mixture of @RequestBody and @RequestProperty

When both @RequestProperty and @RequestBody are present in a single method, final result for query string will be merged with single value @RequestProperty has higher precedence than @RequestBody hash.

Below is an example of this:

/**
* do post with a combination of both single request property, and request body hash. In this
* example, we will combine the two together with single request property has higher
* precedence than query params hash
*
* @param _body
* @param _userId
*/
@RestApi('/post', {
  method: 'POST',
})
doPostWithJsonBodyMixture(
  @RequestBody _body: HttpBinRequest,
  @RequestProperty('userId') _userId: string,
): ApiResponse<HttpBinResponse> {}

Simple POST Rest Calls with FormData Body

@RestApi('/anything', {
  method: 'POST',
})
doPostWithFormBodyData(
  @FormDataBody('unitPrice') _unitPrice: number,
  @FormDataBody('quantity') _qty: number,
): ApiResponse<HttpBinResponse> {}

Simple POST Rest Calls with File Upload as Stream

This example uploads the file as a single stream

@RestApi('/post', {
  method: 'POST',
  headers: {
    'Content-Type': 'multipart/form-data',
  },
})
doSimpleUploadFileWithStreamHttpBinPost(
  @FileUploadBody _fileToUpload: any,
): ApiResponse<HttpBinResponse> {}

This expects your response to be a buffer. Below is how you can craft the buffer for Node Js

import fs from 'fs';
const sampleSmsFileStream = fs.createReadStream('SampleSms.txt');
const apiResponse =
  myPublicDataStoreInstance.doSimpleUploadFileWithStreamHttpBinPost(sampleSmsFileStream);

URL Notes

By default, the library will construct the url to use as:

  • When @RestApi.url is a relative url (for example “/myAPI”). The url by appended the url from @RestApi to baseUrl from @RestClient as:
urlToUse = @RestClient.baseUrl + @RestApi.url
  • When @RestApi.url is an absolute url which starts with http:// or https:// (for example “https://httpbin.org/get” or “http://httpbin.org/get”). That absolute url will be used and won’t be appended to the baseUrl
urlToUse = @RestApi.url

Type casting your response type

Sometimes it might be useful to cast / parsing the json object in the response to match certain object type. We can do so with this library using this approach.

Then RestClient class will look something like this

import {
  RestClient,
  RestApi,
  CredentialProperty,
  RequestBody,
  PathParam,
  FileUploadBody,
  QueryParams,
  FormDataBody,
  ApiResponse,
} from 'restapi-typescript-decorators';

// First define a custom interface
// interface for request
interface NumberPair {
  a: number;
  b: number;
}

// interface for response
interface CollectionSum {
  sum: number;
}

@RestClient({
  baseUrl: 'https://httpbin.org',
})
export class TypeCastApiDataStore {
  @RestApi('/calculateSum', {
    method: 'POST',
  })
  doPostWithTypeCasting(@RequestBody requestBody: NumberPair): ApiResponse<CollectionSum> {}
}

Max timeout for API

You can set a max timeout using the timeout attribute. In which the API will be aborted if the timeout has passed.

In this example, the actual API will return in 10 seconds, but the client will timeout and abort the request in 3 seconds

@RestApi('/delay/10', {
  timeout: 3000,
})
doSimpleTimeoutAPI(): ApiResponse<HttpBinResponse> {}

API Retries

For cases when API can fail due to some QPS (Query Per Second) requirements and the vendor wants the user to attempt a retry at a later time, you can set the parameter for retryConfigs which allows the API to be retried. This way the API will be called again until the totalRetry has passed. To use this, simply set the retryConfigs under the @RestApi decorator.

This example below will retry if there’s failure in the response. It will wait a second before attempting a new retry.

As for checking how many retries has been attempted to reach the API. You can refer to the retryCount property of the ApiResponse.

Note:

  • That when the user attempted to abort the API calls manually using the abort() method from ApiResponse, this action will stop the API from further retries.
  • Another note is that the client will respect server Retry-After response header. And will attempt to retry after that delay. At the moment we only support Retry-After that is of number of seconds to invoke an API retry
@RestClient({
  baseUrl: 'http://localhost:8080',
})
export class RetryDataStore {
  @RestApi('/hello', {
    retryConfigs: {
      count: 5, // maximum retry 5 times
      delay: 1000, // retry after 1 second
    },
  })
  doApiWithRetry(): ApiResponse<HttpBinResponse> {}
}

Understanding the ApiResponse.result Promise

It’s the promise that wrapped around the fetch calls. At the moment, the API will return the resolved promise state when the API is successful, and rejected state if the call is aborted by the user or it’s an API network error.

Request and Response Format

By default, the library will help parsing of the response when you set the proper value for Accept Header.

To use the default parser, you can set the Accept Header. This example below will tell the library to parse the response as if the response is a XML. The default behavior is to parse response as JSON.

Parse JSON Request

The default header value for Content-Type is application/json. You can also be explicit about it. But basically it will transform your JSON request object into JSON string understood by the backend that consumes JSON.

@RestApi('/post', {
  method: 'POST',
  // the following header value is implied
  //  headers: {
  //    'Content-Type': 'application/xml',
  //  },
})
doSimpleHttpBinPostJsonBody(@RequestBody _body: HttpBinRequest): ApiResponse<HttpBinResponse> {}
Parse URL Encoded Form Request

The default header value for Content-Type is application/x-www-form-urlencoded. When this is provided, the library will send your request in url encoded form format.

@RestApi('/post', {
  method: 'POST',
  headers: {
    'Content-Type': 'application/x-www-form-urlencoded',
  },
})
doSimpleHttpBinPostEncodedForm(
  @RequestBody _body: HttpBinRequest,
): ApiResponse<HttpBinResponse> {}
Parse Response as XML

This will parse the XML response and return them as JSON object

@RestApi('/xml', {
// the following header value is implied
//  headers: {
//    'Accept': 'application/xml',
//  },
})
doSimpleHttpGetWithXmlData(): ApiResponse<HttpBinResponse> {}
Parse Response as JSON

The default header value for Accept is application/json. You can also be explicit about it. But basically it will transform your response into JSON objects.

@RestApi('/json', {
  headers: {
    'Accept': 'application/json',
  },
})
doSimpleJSONGet(): ApiResponse<HttpBinResponse> {}

You can also provide fast-xml-parser custom configurations for the client using @RestClient property xmlParseOptions at the class level.

@RestClient({
  baseUrl: 'https://httpbin.org',
  xmlParseOptions: {
    attrPrefix: '@_',
    textNodeName: '#text',
    ignoreNonTextNodeAttr: true,
    ignoreTextNodeAttr: true,
    ignoreNameSpace: true,
  },
})
export class TransformationApiDataStore {
  @RestApi('/xml', {
    method: 'POST',
    headers: {
      Accept: 'application/xml',
    },
  })
  doSimpleRequestTransformApi(@RequestBody requestBody: NumberPair): ApiResponse<any> {}
}

Transformations

You can use requestTransform and responseTransform to do transformation on the request and response API. You can define the transformation at both the @RestClient or @RestApi level. When both are defined, a more specific tranformation at @RestApi will be used toward the final transformation.

Simple request transform

This example will transform the request before sending the request to the backend. The example will do some translation to the input data before sending the data to the backend.

import {
  RestClient,
  RestApi,
  CredentialProperty,
  RequestBody,
  PathParam,
  FileUploadBody,
  QueryParams,
  FormDataBody,
  ApiResponse,
} from 'restapi-typescript-decorators';

interface NumberPair {
  a: number;
  b: number;
}

@RestClient({
  baseUrl: 'https://httpbin.org',
})
export class TransformationApiDataStore {
  @RestApi('/anything', {
    method: 'POST',
    requestTransform: (
      fetchOptions: Request,
      pair: NumberPair,
      instance: TransformationApiDataStore,
    ): Promise<Request> => {
      const newBody = {
        a: pair.a * 100,
        b: pair.b * 200,
      };

      return Promise.resolve(
        Object.assign(fetchOptions, {
          body: JSON.stringify(newBody),
        }),
      );
    },
  })
  doPostWithRequestTransformation(@RequestBody requestBody: NumberPair): ApiResponse<any> {}
}

const myTransformationApiDataStoreInstance = new TransformationApiDataStore();
const apiResponse = myTransformationApiDataStoreInstance.doPostWithRequestTransformation({
  a: 1,
  b: 2,
});

if (apiResponse) {
  //... follow the above example to get the data from result promise
}

Simple response transform

This example will transform the response before returning the final result to the front end. The example code will add the response values and return the sum as the response

import {
  RestClient,
  RestApi,
  CredentialProperty,
  RequestBody,
  PathParam,
  FileUploadBody,
  QueryParams,
  FormDataBody,
  ApiResponse,
} from 'restapi-typescript-decorators';

interface NumberPair {
  a: number;
  b: number;
}

@RestClient({
  baseUrl: 'https://httpbin.org',
})
export class TransformationApiDataStore {
  @RestApi('/anything', {
    method: 'POST',
    responseTransform: (
      fetchOptions: Request,
      resp: Response,
      instance: TransformationApiDataStore,
    ): Promise<any> => {
      return resp.json().then((respJson) => {
        const pair = <NumberPair>JSON.parse(respJson.data);
        const sum = pair.a + pair.b;

        return Promise.resolve({ sum });
      });
    },
  })
  doPostWithResponseTransformation(@RequestBody requestBody: NumberPair): ApiResponse<any> {}
}

const myTransformationApiDataStoreInstance = new TransformationApiDataStore();
const apiResponse = myTransformationApiDataStoreInstance.doPostWithResponseTransformation({
  a: 300,
  b: 700,
});

if (apiResponse) {
  //... follow the above example to get the data from result promise
}

Config Overrides

We have 3 layers of configs: DefaultConfig (default configs from this library), @RestClient Custom Configs and @RestApi Custom Configs. The final config values are set using this order DefaultConfig, @RestClient, and @RestApi.

Config Override Table

DefaultConfigs @RestClient @RestApi Config To Use
a b c c
a b   b
a   c c
  b c c
a     a
  b   b
    c c

Config Override Example

Below is an example on how to set Custom Config

import {
  RestClient,
  RestApi,
  CredentialProperty,
  RequestBody,
  PathParam,
  FileUploadBody,
  QueryParams,
  FormDataBody,
  ApiResponse,
} from 'restapi-typescript-decorators';

import { HttpBinResponse } from './types';

@RestClient({
  baseUrl: 'https://httpbin.org',
  headers: {
    'Accept-Encoding': 'ASCII',
    '--Rest-Client-Custom-Header': '<some_value_@Restclient_111>',
    '--Rest-Api-Custom-Header': '<this_value_will_overrided>',
  },
})
export class OverrideConfigApiDataStore {
  @RestApi('/anything', {
    method: 'POST',
    mode: 'no-cors',
    cache: 'reload',
    credentials: 'same-origin',
    headers: {
      'Accept-Encoding': 'UTF8',
      'Content-Type': '<some_value_@RestApi_333>',
      '--Rest-Api-Custom-Header': '<some_value_@RestApi_222>',
    },
  })
  doPostWithCustomRestApiConfig(): ApiResponse<HttpBinResponse> {}
}

With the above example

  • --Rest-Api-Custom-Header: will be <some_value_@RestApi_222> because it’s set in @RestApi which has more specificity even though its value in @RestClient is <this_value_will_overrided>
  • --Rest-Client-Custom-Header: will be <some_value_@Restclient_111> because it’s set inside of @RestApi although it’s not defined anywhere else in DefaultConfigs or @RestClient
  • Content-Type: will be application/json because it’s set in the DefaultConfigs even though we didn’t specify it.

Notes

  • For POST method and POST JSON body of appplication/json, the request will stringify and properly saves it into the body
  • Note that when both @RequestBody and @FormDataBody are used, @FormDataBody will have higher precendence

How to contribute?

Make the change and create PR against master.

Issues?

If you have any issue with the API, feel free to file a bug on Github at https://github.com/synle/restapi-typescript-decorators/issues/new

Note on release pipeline

To publish directly to npm

Beta Tags
npm run build && \
npm version prepatch && \
npm publish --tag beta
Prod Tags
npm run build && \
npm version patch && \
git push origin master