feat: wrap public key in a class

web3.js/src/publickey.js

@@ -0,0 +1,70 @@
+// @flow
+
+import BN from 'bn.js';
+import bs58 from 'bs58';
+
+/**
+ * A public key
+ */
+export class PublicKey {
+  _bn: BN;
+
+  /**
+   * Create a new PublicKey object
+   */
+  constructor(number: string | Buffer | Array<number>) {
+    let radix = 10;
+
+    if (typeof number === 'string' && number.startsWith('0x')) {
+      this._bn = new BN(number.substring(2), 16);
+    } else {
+      this._bn = new BN(number, radix);
+    }
+    if (this._bn.byteLength() > 32) {
+      throw new Error(`Invalid public key input`);
+    }
+  }
+
+  /**
+   * Checks if the provided object is a PublicKey
+   */
+  static isPublicKey(o: Object): boolean {
+    return o instanceof PublicKey;
+  }
+
+  /**
+   * Checks if two publicKeys are equal
+   */
+  equals(publicKey: PublicKey): boolean {
+    return this._bn.eq(publicKey._bn);
+  }
+
+  /**
+   * Return the base-58 representation of the public key
+   */
+  toBase58(): string {
+    return bs58.encode(this.toBuffer());
+  }
+
+  /**
+   * Return the base-58 representation of the public key
+   */
+  toBuffer(): Buffer {
+    const b = this._bn.toBuffer();
+    if (b.length === 32) {
+      return b;
+    }
+
+    const zeroPad = new Buffer(32);
+    b.copy(zeroPad, 32 - b.length);
+    return zeroPad;
+  }
+
+  /**
+   * Returns a string representation of the public key
+   */
+  toString(): string {
+    return this.toBase58();
+  }
+}
+