feat: add bip122:p2wpkh account support (#294)

* feat: add bip122:p2wpkh account support

* refactor: add and use asInternalAccountStruct for internal accounts

package.json

@@ -41,6 +41,7 @@
     "@metamask/snaps-sdk": "^4.0.0",
     "@metamask/utils": "^8.3.0",
     "@types/uuid": "^9.0.1",
+    "bech32": "^2.0.0",
     "superstruct": "^1.0.3",
     "uuid": "^9.0.0"
   },

src/api.ts

@@ -14,6 +14,8 @@ import {
 } from 'superstruct';
 
 import type { StaticAssertAbstractAccount } from './base-types';
+import type { BtcP2wpkhAccount } from './btc';
+import { BtcP2wpkhAccountStruct, BtcAccountType } from './btc';
 import type { EthEoaAccount, EthErc4337Account } from './eth';
 import {
   EthEoaAccountStruct,
@@ -27,18 +29,19 @@ import { UuidStruct } from './utils';
  * Type of supported accounts.
  */
 export type KeyringAccounts = StaticAssertAbstractAccount<
-  EthEoaAccount | EthErc4337Account
+  EthEoaAccount | EthErc4337Account | BtcP2wpkhAccount
 >;
 
 /**
  * Mapping between account types and their matching `superstruct` schema.
  */
 export const KeyringAccountStructs: Record<
   string,
-  Struct<EthEoaAccount> | Struct<EthErc4337Account>
+  Struct<EthEoaAccount> | Struct<EthErc4337Account> | Struct<BtcP2wpkhAccount>
 > = {
   [`${EthAccountType.Eoa}`]: EthEoaAccountStruct,
   [`${EthAccountType.Erc4337}`]: EthErc4337AccountStruct,
+  [`${BtcAccountType.P2wpkh}`]: BtcP2wpkhAccountStruct,
 };
 
 /**
@@ -48,7 +51,11 @@ export const BaseKeyringAccountStruct = object({
   /**
    * Account type.
    */
-  type: enums([`${EthAccountType.Eoa}`, `${EthAccountType.Erc4337}`]),
+  type: enums([
+    `${EthAccountType.Eoa}`,
+    `${EthAccountType.Erc4337}`,
+    `${BtcAccountType.P2wpkh}`,
+  ]),
 });
 
 /**

src/btc/index.ts

@@ -0,0 +1 @@
+export * from './types';

src/btc/types.test.ts

@@ -0,0 +1,41 @@
+import { BtcP2wpkhAddressStruct } from './types';
+
+describe('types', () => {
+  describe('BtcP2wpkhAddressStruct', () => {
+    const errorPrefix = 'Could not decode P2WPKH address';
+
+    it.each([
+      'bc1qw508d6qejxtdg4y5r3zarvary0c5xw7kv8f3t4',
+      'tb1qw508d6qejxtdg4y5r3zarvary0c5xw7kxpjzsx',
+    ])('is valid address; %s', (address) => {
+      expect(() => BtcP2wpkhAddressStruct.assert(address)).not.toThrow();
+    });
+
+    it.each([
+      // Too short
+      '',
+      'bc1q',
+      // Must have at least 6 characters after separator '1'
+      'bc1q000',
+    ])('throws an error if address is too short: %s', (address) => {
+      expect(() => BtcP2wpkhAddressStruct.assert(address)).toThrow(
+        `${errorPrefix}: ${address} too short`,
+      );
+    });
+
+    it('throws an error if address is too long', () => {
+      const address =
+        'bc1qw508d6qejxtdg4y5r3zarvary0c5xw7kv8f3t4w508d6qejxtdg4y5r3zarvary0c5xw7kv8f3t4w508d6qejxtdg4y5r3zarvary0c5xw7kv8f3t4';
+      expect(() => BtcP2wpkhAddressStruct.assert(address)).toThrow(
+        `${errorPrefix}: Exceeds length limit`,
+      );
+    });
+
+    it('throws an error if there no seperator', () => {
+      const address = 'bc0qw508d6qejxtdg4y5r3zarvary0c5xw7kv8f3t4';
+      expect(() => BtcP2wpkhAddressStruct.assert(address)).toThrow(
+        `${errorPrefix}: No separator character for ${address}`,
+      );
+    });
+  });
+});

src/btc/types.ts

@@ -0,0 +1,51 @@
+import { bech32 } from 'bech32';
+import type { Infer } from 'superstruct';
+import { object, string, array, enums, literal, refine } from 'superstruct';
+
+import { BaseAccount } from '../base-types';
+
+export const BtcP2wpkhAddressStruct = refine(
+  string(),
+  'BtcP2wpkhAddressStruct',
+  (address: string) => {
+    try {
+      bech32.decode(address);
+    } catch (error) {
+      return new Error(
+        `Could not decode P2WPKH address: ${(error as Error).message}`,
+      );
+    }
+    return true;
+  },
+);
+
+/**
+ * Supported Bitcoin methods.
+ */
+export enum BtcMethod {
+  // General transaction methods
+  SendTransaction = 'btc_sendTransaction',
+}
+
+/**
+ * Supported Bitcoin account types.
+ */
+export enum BtcAccountType {
+  P2wpkh = 'bip122:p2wpkh',
+}
+
+export const BtcP2wpkhAccountStruct = object({
+  ...BaseAccount,
+
+  /**
+   * Account type.
+   */
+  type: literal(`${BtcAccountType.P2wpkh}`),
+
+  /**
+   * Account supported methods.
+   */
+  methods: array(enums([`${BtcMethod.SendTransaction}`])),
+});
+
+export type BtcP2wpkhAccount = Infer<typeof BtcP2wpkhAccountStruct>;

src/index.ts

@@ -1,4 +1,5 @@
 export * from './api';
+export * from './btc';
 export * from './contexts';
 export * from './eth';
 export * from './events';

src/internal/types.test.ts

@@ -3,13 +3,19 @@ import { assert } from 'superstruct';
 import { InternalAccountStruct } from '.';
 
 describe('InternalAccount', () => {
-  it('should have the correct structure', () => {
+  it.each([
+    { type: 'eip155:eoa', address: '0x000' },
+    {
+      type: 'bip122:p2wpkh',
+      address: 'bc1qw508d6qejxtdg4y5r3zarvary0c5xw7kv8f3t4',
+    },
+  ])('should have the correct structure: %s', ({ type, address }) => {
     const account = {
       id: '606a7759-b0fb-48e4-9874-bab62ff8e7eb',
-      address: '0x000',
+      address,
       options: {},
       methods: [],
-      type: 'eip155:eoa',
+      type,
       metadata: {
         keyring: {
           type: 'Test Keyring',

src/internal/types.ts

@@ -2,6 +2,7 @@ import type { Infer, Struct } from 'superstruct';
 import { boolean, string, number, define, mask, validate } from 'superstruct';
 
 import { BaseKeyringAccountStruct } from '../api';
+import { BtcP2wpkhAccountStruct, BtcAccountType } from '../btc/types';
 import {
   EthEoaAccountStruct,
   EthErc4337AccountStruct,
@@ -27,28 +28,51 @@ export const InternalAccountMetadataStruct = object({
   }),
 });
 
-export const InternalEthEoaAccountStruct = object({
-  ...EthEoaAccountStruct.schema,
-  ...InternalAccountMetadataStruct.schema,
-});
+/**
+ * Creates an `InternalAccount` from an existing account `superstruct` object.
+ *
+ * @param accountStruct - An account `superstruct` object.
+ * @returns The `InternalAccount` assocaited to `accountStruct`.
+ */
+function asInternalAccountStruct<Account, AccountSchema>(
+  accountStruct: Struct<Account, AccountSchema>,
+) {
+  return object({
+    ...accountStruct.schema,
+    ...InternalAccountMetadataStruct.schema,
+  });
+}
 
-export type InternalEthEoaAccount = Infer<typeof InternalEthEoaAccountStruct>;
+export const InternalEthEoaAccountStruct =
+  asInternalAccountStruct(EthEoaAccountStruct);
 
-export const InternalEthErc4337AccountStruct = object({
-  ...EthErc4337AccountStruct.schema,
-  ...InternalAccountMetadataStruct.schema,
-});
+export const InternalEthErc4337AccountStruct = asInternalAccountStruct(
+  EthErc4337AccountStruct,
+);
+
+export const InternalBtcP2wpkhAccountStruct = asInternalAccountStruct(
+  BtcP2wpkhAccountStruct,
+);
+
+export type InternalEthEoaAccount = Infer<typeof InternalEthEoaAccountStruct>;
 
 export type InternalEthErc4337Account = Infer<
   typeof InternalEthErc4337AccountStruct
 >;
 
+export type InternalBtcP2wpkhAccount = Infer<
+  typeof InternalBtcP2wpkhAccountStruct
+>;
+
 export const InternalAccountStructs: Record<
   string,
-  Struct<InternalEthEoaAccount> | Struct<InternalEthErc4337Account>
+  | Struct<InternalEthEoaAccount>
+  | Struct<InternalEthErc4337Account>
+  | Struct<InternalBtcP2wpkhAccount>
 > = {
   [`${EthAccountType.Eoa}`]: InternalEthEoaAccountStruct,
   [`${EthAccountType.Erc4337}`]: InternalEthErc4337AccountStruct,
+  [`${BtcAccountType.P2wpkh}`]: InternalBtcP2wpkhAccountStruct,
 };
 
 export const InternalAccountStruct = define(

yarn.lock

@@ -1067,6 +1067,7 @@ __metadata:
     "@types/uuid": ^9.0.1
     "@typescript-eslint/eslint-plugin": ^5.43.0
     "@typescript-eslint/parser": ^5.43.0
+    bech32: ^2.0.0
     depcheck: ^1.4.3
     eslint: ^8.27.0
     eslint-config-prettier: ^8.5.0
@@ -2206,6 +2207,13 @@ __metadata:
   languageName: node
   linkType: hard
 
+"bech32@npm:^2.0.0":
+  version: 2.0.0
+  resolution: "bech32@npm:2.0.0"
+  checksum: fa15acb270b59aa496734a01f9155677b478987b773bf701f465858bf1606c6a970085babd43d71ce61895f1baa594cb41a2cd1394bd2c6698f03cc2d811300e
+  languageName: node
+  linkType: hard
+
 "big-integer@npm:^1.6.44":
   version: 1.6.51
   resolution: "big-integer@npm:1.6.51"