feat: add borsh utilities and public key support (#17239)

* feat: add borsh utilities and public key support

* fix: make bn internal for flow

* fix: add Buffer import in borsh file

web3.js/src/index.ts

@@ -16,6 +16,7 @@ export * from './transaction';
 export * from './validator-info';
 export * from './vote-account';
 export * from './sysvar';
+export * from './util/borsh-schema';
 export * from './util/send-and-confirm-transaction';
 export * from './util/send-and-confirm-raw-transaction';
 export * from './util/cluster';

web3.js/src/publickey.ts

@@ -4,6 +4,7 @@ import nacl from 'tweetnacl';
 import {sha256} from 'crypto-hash';
 import {Buffer} from 'buffer';
 
+import {Struct, SOLANA_SCHEMA} from './util/borsh-schema';
 import {toBuffer} from './util/to-buffer';
 
 /**
@@ -11,10 +12,27 @@ import {toBuffer} from './util/to-buffer';
  */
 export const MAX_SEED_LENGTH = 32;
 
+type PublicKeyInitData =
+  | number
+  | string
+  | Buffer
+  | Uint8Array
+  | Array<number>
+  | PublicKeyData;
+
+type PublicKeyData = {
+  /** @internal */
+  _bn: BN;
+};
+
+function isPublicKeyData(value: PublicKeyInitData): value is PublicKeyData {
+  return (value as PublicKeyData)._bn !== undefined;
+}
+
 /**
  * A public key
  */
-export class PublicKey {
+export class PublicKey extends Struct {
   /** @internal */
   _bn: BN;
 
@@ -22,20 +40,25 @@ export class PublicKey {
    * Create a new PublicKey object
    * @param value ed25519 public key as buffer or base-58 encoded string
    */
-  constructor(value: number | string | Buffer | Uint8Array | Array<number>) {
-    if (typeof value === 'string') {
-      // assume base 58 encoding by default
-      const decoded = bs58.decode(value);
-      if (decoded.length != 32) {
+  constructor(value: PublicKeyInitData) {
+    super({});
+    if (isPublicKeyData(value)) {
+      this._bn = value._bn;
+    } else {
+      if (typeof value === 'string') {
+        // assume base 58 encoding by default
+        const decoded = bs58.decode(value);
+        if (decoded.length != 32) {
+          throw new Error(`Invalid public key input`);
+        }
+        this._bn = new BN(decoded);
+      } else {
+        this._bn = new BN(value);
+      }
+
+      if (this._bn.byteLength() > 32) {
         throw new Error(`Invalid public key input`);
       }
-      this._bn = new BN(decoded);
-    } else {
-      this._bn = new BN(value);
-    }
-
-    if (this._bn.byteLength() > 32) {
-      throw new Error(`Invalid public key input`);
     }
   }
 
@@ -167,6 +190,11 @@ export class PublicKey {
   }
 }
 
+SOLANA_SCHEMA.set(PublicKey, {
+  kind: 'struct',
+  fields: [['_bn', 'u256']],
+});
+
 // @ts-ignore
 let naclLowLevel = nacl.lowlevel;
 

web3.js/src/util/borsh-schema.ts

@@ -0,0 +1,34 @@
+import {Buffer} from 'buffer';
+import {serialize, deserialize} from 'borsh';
+
+// Class wrapping a plain object
+export class Struct {
+  constructor(properties: any) {
+    Object.assign(this, properties);
+  }
+
+  encode(): Buffer {
+    return Buffer.from(serialize(SOLANA_SCHEMA, this));
+  }
+
+  static decode(data: Buffer): any {
+    return deserialize(SOLANA_SCHEMA, this, data);
+  }
+}
+
+// Class representing a Rust-compatible enum, since enums are only strings or
+// numbers in pure JS
+export class Enum extends Struct {
+  enum: string = '';
+  constructor(properties: any) {
+    super(properties);
+    if (Object.keys(properties).length !== 1) {
+      throw new Error('Enum can only take single value');
+    }
+    Object.keys(properties).map(key => {
+      this.enum = key;
+    });
+  }
+}
+
+export const SOLANA_SCHEMA: Map<Function, any> = new Map();