fix: /accounts/{accountId}/convert encoding for ecdsa (#1280)

* start the rework

* Update comment in tests

src/services/accounts/AccountsConvertService.spec.ts

@@ -150,6 +150,29 @@ describe('Convert accounts', () => {
 		).toStrictEqual(expectedResponse);
 	});
 
+	// This ensures the behaviour of the endpoint correctly converts a kusama publicKey given
+	// the following input. See PR: https://github.com/paritytech/substrate-api-sidecar/pull/1280
+	it('Should convert a valid Kusama publicKey when `publicKey` equals `true`', () => {
+		const expectedResponse = {
+			accountId:
+				'0x96074594cccf1cd185fa8a72ceaeefd86648f8d45514f3ce33c31bdd07e4655d',
+			address: 'Fy2rsYCoowQBtuFXqLE65ehAY9T6KWcGiNCQAyPDCkfpm4s',
+			network: 'kusama',
+			publicKey: true,
+			scheme: 'sr25519',
+			ss58Prefix: '2',
+		};
+
+		const kusamaPublicKey =
+			'0x96074594cccf1cd185fa8a72ceaeefd86648f8d45514f3ce33c31bdd07e4655d';
+
+		expect(
+			sanitizeNumbers(
+				validateService.accountConvert(kusamaPublicKey, 'sr25519', 2, true)
+			)
+		).toStrictEqual(expectedResponse);
+	});
+
 	// We try to convert a Polkadot AccountId to an SS58 Address by setting the publicKey=true
 	// which is not correct and that is why in the response we have an invalid address.
 	// If we would like to convert it correctly and have the expected SS58 address
@@ -158,7 +181,7 @@ describe('Convert accounts', () => {
 		const expectedResponse = {
 			ss58Prefix: '0',
 			network: 'polkadot',
-			address: '12ZviSbX1Pzmnw1mg4FUg6Qra2CW7Q3z9iqmcWKWUphp5qgq',
+			address: '1rsCBWhPgyDETNS9yxnANSnm3KAtkxm4mu9jjfMhDF6xaV8',
 			accountId:
 				'0x2607fd20388303bd409e551202ee47b753b4382feac914e9f7ab0d4f728c2bf7',
 			scheme: 'ecdsa',

src/services/accounts/AccountsConvertService.ts

@@ -16,13 +16,25 @@
 
 import { Keyring } from '@polkadot/api';
 import { isHex } from '@polkadot/util';
-import { allNetworks } from '@polkadot/util-crypto';
-import { blake2AsHex } from '@polkadot/util-crypto';
+import { hexToU8a } from '@polkadot/util';
+import { allNetworks, blake2AsHex } from '@polkadot/util-crypto';
 import { BadRequest } from 'http-errors';
 
 import { IAccountConvert } from '../../types/responses/AccountConvert';
 import { AbstractService } from '../AbstractService';
 
+/**
+ * Copyright 2023 via polkadot-js/common
+ *
+ * The slightly modified below logic is copyrighted from polkadot-js/common . The exact path to the code can be seen here:
+ * https://github.com/polkadot-js/common/blob/e5cb0ba2b4a6b5817626cc964b4f66334f2410e4/packages/keyring/src/pair/index.ts#L44-L49
+ */
+const TYPE_ADDRESS = {
+	ecdsa: (p: string) => (hexToU8a(p).length > 32 ? blake2AsHex(p) : p),
+	ed25519: (p: string) => p,
+	sr25519: (p: string) => p,
+};
+
 export class AccountsConvertService extends AbstractService {
 	/**
 	 * Takes a given AccountId or Public Key (hex) and converts it to an SS58 address.
@@ -59,7 +71,9 @@ export class AccountsConvertService extends AbstractService {
 			);
 		}
 
-		const accountId2Encode = publicKey ? blake2AsHex(accountId) : accountId;
+		const accountId2Encode = publicKey
+			? TYPE_ADDRESS[scheme](accountId)
+			: accountId;
 
 		const keyring = new Keyring({ type: scheme, ss58Format: ss58Prefix });
 		const address = keyring.encodeAddress(accountId2Encode, ss58Prefix);