fixup! add test to have 100% coverage

src/derivers/bip39.test.ts

@@ -7,7 +7,7 @@ import {
 import * as hmacModule from '@noble/hashes/hmac';
 
 import fixtures from '../../test/fixtures';
-import { secp256k1, ed25519Bip32 } from '../curves';
+import { secp256k1, ed25519Bip32, type Curve } from '../curves';
 import {
   entropyToCip3MasterNode,
   createBip39KeyFromSeed,
@@ -69,6 +69,17 @@ describe('createBip39KeyFromSeed', () => {
       );
     },
   );
+
+  it('throws with unsupported masterNodeGenerationSpec error', async () => {
+    await expect(
+      deriveChildKey({
+        path: '',
+        curve: {
+          masterNodeGenerationSpec: 'notValidMasterNodeGenerationSpec',
+        } as unknown as Curve,
+      }),
+    ).rejects.toThrow('Unsupported master node generation spec.');
+  });
 });
 
 describe('Cip3', () => {

src/derivers/cip3.test.ts

@@ -2,12 +2,13 @@ import { bytesToHex, hexToBytes } from '@metamask/utils';
 
 import fixtures from '../../test/fixtures';
 import { BIP_32_HARDENED_OFFSET } from '../constants';
-import { ed25519Bip32 } from '../curves';
+import { ed25519, ed25519Bip32 } from '../curves';
 import { SLIP10Node } from '../SLIP10Node';
 import {
   add,
   bigIntToBytes,
   bytesToBigInt,
+  type Cip3SupportedCurve,
   deriveChainCode,
   deriveChildKey,
   derivePrivateKey,
@@ -165,6 +166,18 @@ describe('Cip3', () => {
           JSON.stringify(addressIndexNode),
         );
       });
+
+      it('throws with unsupported curve error', async () => {
+        await expect(
+          deriveChildKey({
+            node: await SLIP10Node.fromJSON(bip39Node),
+            path: purpose,
+            curve: ed25519 as unknown as Cip3SupportedCurve,
+          }),
+        ).rejects.toThrow(
+          `Unsupported curve: Only ed25519Bip32 is supported by CIP3.`,
+        );
+      });
     });
   });
 

src/derivers/cip3.ts

@@ -126,7 +126,7 @@ export const getKeyExtension = (
   ]);
 };
 
-type Cip3SupportedCurve = Extract<Curve, { name: 'ed25519Bip32' }>;
+export type Cip3SupportedCurve = Extract<Curve, { name: 'ed25519Bip32' }>;
 
 type DeriveKeyBaseArgs = { childIndex: number };