test: add test for bip371

Author: Heracles4179

test/bip371.spec.ts

@@ -0,0 +1,23 @@
+import { toXOnly } from 'bitcoinjs-lib';
+import * as assert from 'assert';
+
+describe('toXOnly', () => {
+  it('should return the input if the pubKey length is 32', () => {
+    const pubKey = new Uint8Array(32).fill(1); // Example 32-byte public key
+    const result = toXOnly(pubKey);
+    assert.strictEqual(result, pubKey); // Expect the same array (reference equality)
+  });
+
+  it('should return the sliced key if the pubKey length is greater than 32', () => {
+    const pubKey = new Uint8Array(33).fill(1);
+    pubKey[0] = 0; // Add a leading byte
+    const result = toXOnly(pubKey);
+    assert.deepStrictEqual(result, pubKey.slice(1, 33)); // Expect the sliced array
+  });
+
+  it('should throw an error if the pubKey length is less than 32', () => {
+    const pubKey = new Uint8Array(31).fill(1); // Example invalid public key
+    const result = toXOnly(pubKey);
+    assert.deepStrictEqual(result, pubKey.slice(1, 33)); // Expect the sliced array
+  });
+});