[xp] refactor address class

packages/massa-web3/src/experimental/basicElements/address.ts

@@ -1,14 +1,15 @@
 import Base58 from '../crypto/base58'
 import Serializer from '../crypto/interfaces/serializer'
 import { Version } from '../crypto/interfaces/versioner'
-import { checkPrefix } from './internal'
 import { PublicKey } from './keys'
 import varint from 'varint'
 
-const ADDRESS_PREFIX = 'A'
-const ADDRESS_USER_PREFIX = 'U'
-const ADDRESS_CONTRACT_PREFIX = 'S'
+const ADDRESS_USER_PREFIX = 'AU'
+const ADDRESS_CONTRACT_PREFIX = 'AS'
 const UNDERLYING_HASH_LEN = 32
+
+const DEFAULT_VERSION = Version.V0
+
 /**
  * A class representing an address.
  *
@@ -17,37 +18,28 @@ const UNDERLYING_HASH_LEN = 32
  *
  * @privateRemarks
  * Interfaces are used to make the code more modular. To add a new version, you simply need to:
- * - extend the `initFromVersion` method:
- *   - Add a new case in the switch statement with the new algorithms to use.
- *   - Add a new default version matching the last version.
+ * - Change the DEFAULT_VERSION version matching the last version.
  * - check the `fromPublicKey` method to potentially adapt how an address is derived from a public key.
  * - Voila! The code will automatically handle the new version.
  */
 export class Address {
   private bytes: Uint8Array
 
-  protected constructor(
-    public serializer: Serializer,
-    public version: Version,
-    public isEOA: boolean
-  ) {}
+  public version = DEFAULT_VERSION
+  public isEOA = false
 
-  /**
-   * Initialize a new address object from a version.
-   *
-   * @param version - The version of the address.
-   *
-   * @returns A new address instance.
-   *
-   * @throws If the version is not supported.
-   */
-  protected static initFromVersion(version: Version = Version.V0): Address {
-    switch (version) {
-      case Version.V0:
-        return new Address(new Base58(), version, false)
-      default:
-        throw new Error(`unsupported version: ${version}`)
+  protected constructor(public serializer: Serializer = new Base58()) {}
+
+  private getPrefix(str: string): string {
+    const expected = [ADDRESS_USER_PREFIX, ADDRESS_CONTRACT_PREFIX]
+    for (let prefix of expected) {
+      if (str.startsWith(prefix)) {
+        return prefix
+      }
     }
+    throw new Error(
+      `invalid address prefix: one of ${expected.join(' or ')} was expected.`
+    )
   }
 
   /**
@@ -60,29 +52,24 @@ export class Address {
    * @throws If the address string is invalid.
    */
   public static fromString(str: string): Address {
-    const address = Address.initFromVersion()
+    const address = new Address()
 
     try {
-      const prefix = checkPrefix(
-        str,
-        ADDRESS_PREFIX + ADDRESS_USER_PREFIX,
-        ADDRESS_PREFIX + ADDRESS_CONTRACT_PREFIX
-      )
+      const prefix = address.getPrefix(str)
 
-      address.isEOA = str[ADDRESS_PREFIX.length] === ADDRESS_USER_PREFIX
-      const versionedHash = address.serializer.deserialize(
+      address.isEOA = prefix === ADDRESS_USER_PREFIX
+      const versionedBytes = address.serializer.deserialize(
         str.slice(prefix.length)
       )
 
       address.bytes = Uint8Array.from([
         ...varint.encode(address.isEOA ? 0 : 1),
-        ...versionedHash,
+        ...versionedBytes,
       ])
       address.version = address.getVersion()
     } catch (e) {
       throw new Error(`invalid address string: ${e.message}`)
     }
-
     return address
   }
 
@@ -118,13 +105,17 @@ export class Address {
    *
    * @returns A new address object.
    */
-  public static fromPublicKey(publicKey: PublicKey): Address {
-    const address = Address.initFromVersion()
-    const hash = publicKey.hasher.hash(publicKey.toBytes())
+  public static fromPublicKey(
+    publicKey: PublicKey,
+    version = DEFAULT_VERSION
+  ): Address {
+    const address = new Address()
+    const rawBytes = publicKey.hasher.hash(publicKey.toBytes())
+    address.version = version
     address.bytes = Uint8Array.from([
       0 /* EOA*/,
-      ...varint.encode(address.version),
-      ...hash,
+      ...varint.encode(version),
+      ...rawBytes,
     ])
     address.isEOA = true
     return address
@@ -138,7 +129,7 @@ export class Address {
    * @returns A new address object.
    */
   public static fromBytes(bytes: Uint8Array): Address {
-    const address = Address.initFromVersion()
+    const address = new Address()
     address.bytes = bytes
     address.isEOA = address.getType() === 0
     address.version = address.getVersion()
@@ -168,17 +159,18 @@ export class Address {
     // decode version
     varint.decode(this.bytes)
     const versionedBytes = this.bytes.slice(varint.decode.bytes)
-    return `${ADDRESS_PREFIX}${
+    return `${
       this.isEOA ? ADDRESS_USER_PREFIX : ADDRESS_CONTRACT_PREFIX
     }${this.serializer.serialize(versionedBytes)}`
   }
 
   /**
-   * Get byte length of address in binary format .
+   * Get address in binary format from a bytes buffer.
+   * The address should be the first element in the buffer.
    *
-   * @returns The address length in bytes.
+   * @returns The address in bytes format.
    */
-  static getByteLength(data: Uint8Array): number {
+  static extractFromBuffer(data: Uint8Array): Uint8Array {
     // addr type
     varint.decode(data)
     let addrByteLen = varint.decode.bytes
@@ -187,6 +179,6 @@ export class Address {
     addrByteLen += varint.decode.bytes
 
     addrByteLen += UNDERLYING_HASH_LEN
-    return addrByteLen
+    return data.slice(0, addrByteLen)
   }
 }

packages/massa-web3/src/experimental/basicElements/operationManager.ts

@@ -164,11 +164,9 @@ export class OperationManager {
 
     switch (operationDetails.type) {
       case OperationType.Transaction: {
-        const addrLen = Address.getByteLength(data.slice(offset))
-        const recipientAddress = Address.fromBytes(
-          data.slice(offset, offset + addrLen)
-        )
-        offset += addrLen
+        const addrBytes = Address.extractFromBuffer(data.slice(offset))
+        const recipientAddress = Address.fromBytes(addrBytes)
+        offset += addrBytes.length
         return {
           ...operationDetails,
           recipientAddress,

packages/massa-web3/test/experimental/unit/address.spec.ts

@@ -57,9 +57,9 @@ describe('Address tests', () => {
 
   test('getByteLength returns correct length', () => {
     const address = Address.fromPublicKey(account.publicKey)
-    const bytes = address.toBytes()
-    const byteLength = Address.getByteLength(bytes)
+    const buffer = Uint8Array.from([...address.toBytes(), 1, 2, 3, 4])
+    const addressBytes = Address.extractFromBuffer(buffer)
 
-    expect(byteLength).toBe(bytes.length)
+    expect(addressBytes).toStrictEqual(address.toBytes())
   })
 })