Use async in download wallet (#127)

* convert keystore gen to async

* add & use type UtcKeystore

* add types, refactor

* remove unneeded prop checking

common/containers/Tabs/GenerateWallet/components/DownloadWallet.jsx

@@ -4,6 +4,7 @@ import translate from 'translations';
 import type PrivKeyWallet from 'libs/wallet/privkey';
 import { makeBlob } from 'utils/blob';
 import { getV3Filename } from 'libs/keystore';
+import type { UtcKeystore } from 'libs/keystore';
 
 type Props = {
   wallet: PrivKeyWallet,
@@ -11,32 +12,43 @@ type Props = {
   continueToPaper: Function
 };
 
+type State = {
+  hasDownloadedWallet: boolean,
+  address: string,
+  keystore: UtcKeystore | null
+};
+
 export default class DownloadWallet extends Component {
   props: Props;
-  keystore: Object;
-  state = {
+  state: State = {
     hasDownloadedWallet: false,
-    address: ''
+    address: '',
+    keystore: null
   };
 
   componentDidMount() {
-    if (!this.props.wallet) return;
     this.props.wallet.getAddress().then(addr => {
       this.setState({ address: addr });
     });
   }
 
   componentWillMount() {
-    this.keystore = this.props.wallet.toKeystore(this.props.password);
+    this.props.wallet.toKeystore(this.props.password).then(utcKeystore => {
+      this.setState({ keystore: utcKeystore });
+    });
   }
   componentWillUpdate(nextProps: Props) {
     if (this.props.wallet !== nextProps.wallet) {
-      this.keystore = nextProps.wallet.toKeystore(nextProps.password);
+      nextProps.wallet.toKeystore(nextProps.password).then(utcKeystore => {
+        this.setState({ keystore: utcKeystore });
+      });
     }
   }
 
   _markDownloaded = () => {
+    if (this.state.keystore) {
       this.setState({ hasDownloadedWallet: true });
+    }
   };
 
   _handleContinue = () => {
@@ -72,6 +84,7 @@ export default class DownloadWallet extends Component {
             className="btn btn-primary btn-block"
             aria-label="Download Keystore File (UTC / JSON · Recommended · Encrypted)"
             aria-describedby="x_KeystoreDesc"
+            disabled={!this.state.keystore}
             download={this.getFilename()}
             href={this.getBlob()}
             onClick={this._markDownloaded}
@@ -115,7 +128,9 @@ export default class DownloadWallet extends Component {
   }
 
   getBlob() {
-    return makeBlob('text/json;charset=UTF-8', this.keystore);
+    if (this.state.keystore) {
+      return makeBlob('text/json;charset=UTF-8', this.state.keystore);
+    }
   }
 
   getFilename() {

common/libs/keystore.js

@@ -10,6 +10,13 @@ import { sha3, privateToAddress } from 'ethereumjs-util';
 import scrypt from 'scryptsy';
 import uuid from 'uuid';
 
+export type UtcKeystore = {
+  version: number,
+  id: string,
+  address: string,
+  Crypto: Object
+};
+
 //adapted from https://github.com/kvhnuke/etherwallet/blob/de536ffebb4f2d1af892a32697e89d1a0d906b01/app/scripts/myetherwallet.js#L342
 export function determineKeystoreType(file: string): string {
   const parsed = JSON.parse(file);
@@ -106,7 +113,7 @@ export function pkeyToKeystore(
   pkey: Buffer,
   address: string,
   password: string
-) {
+): UtcKeystore {
   const salt = randomBytes(32);
   const iv = randomBytes(16);
   let derivedKey;

common/libs/wallet/privkey.js

@@ -11,6 +11,7 @@ import { signRawTxWithPrivKey, signMessageWithPrivKey } from 'libs/signing';
 
 import { isValidPrivKey } from 'libs/validators';
 import type { RawTransaction } from 'libs/transaction';
+import type { UtcKeystore } from 'libs/keystore';
 
 export default class PrivKeyWallet extends BaseWallet {
   privKey: Buffer;
@@ -40,7 +41,7 @@ export default class PrivKeyWallet extends BaseWallet {
     return new PrivKeyWallet(randomBytes(32));
   }
 
-  toKeystore(password: string): Promise<any> {
+  toKeystore(password: string): Promise<UtcKeystore> {
     return new Promise(resolve => {
       this.getNakedAddress().then(address => {
         resolve(pkeyToKeystore(this.privKey, address, password));