Added supported chains endpoint in Census3

CHANGELOG.md

@@ -5,6 +5,12 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [Unreleased]
+
+### Added
+
+- Census3 supported chains information.
+
 ## [0.2.0] - 2023-09-04
 
 ### Fixed

src/api/census3/index.ts

@@ -1,4 +1,5 @@
 export * from './census';
 export * from './strategy';
+export * from './service';
 export * from './token';
 export * from './errors';

src/api/census3/service.ts

@@ -0,0 +1,35 @@
+import axios from 'axios';
+import { Census3API } from './api';
+
+enum Census3ServiceAPIMethods {
+  INFO = '/info',
+}
+
+export interface ICensus3ServiceInfoResponse {
+  /**
+   * The list of supported chains
+   */
+  chainIDs: Array<number>;
+}
+
+export abstract class Census3ServiceAPI extends Census3API {
+  /**
+   * Cannot be constructed.
+   */
+  private constructor() {
+    super();
+  }
+
+  /**
+   * Fetches supported chains from the service
+   *
+   * @param {string} url API endpoint URL
+   * @returns {Promise<ICensus3ServiceInfoResponse>}
+   */
+  public static info(url: string): Promise<ICensus3ServiceInfoResponse> {
+    return axios
+      .get<ICensus3ServiceInfoResponse>(url + Census3ServiceAPIMethods.INFO)
+      .then((response) => response.data)
+      .catch(this.isApiError);
+  }
+}

src/census3.ts

@@ -2,6 +2,7 @@ import { CENSUS3_URL } from './util/constants';
 import { ClientOptions } from './client';
 import {
   Census3CensusAPI,
+  Census3ServiceAPI,
   Census3StrategyAPI,
   Census3TokenAPI,
   ICensus3CensusResponse,
@@ -43,6 +44,15 @@ export class VocdoniCensus3Client {
     return Census3TokenAPI.list(this.url).then((list) => list.tokens ?? []);
   }
 
+  /**
+   * Returns a list of supported chain identifiers
+   *
+   * @returns {Promise<number[]>} Supported chain list
+   */
+  getSupportedChains(): Promise<number[]> {
+    return Census3ServiceAPI.info(this.url).then((info) => info.chainIDs ?? []);
+  }
+
   /**
    * Returns a list of supported tokens type
    *