Make icon generation more robust (#632)

* Make icon generation more robust

* Update packages/ui-shared/src/icons/polkadot.ts

packages/react-identicon/src/icons/Jdenticon.tsx

@@ -4,15 +4,18 @@
 import type { Props } from '../types';
 
 import * as jdenticon from 'jdenticon';
-import React from 'react';
+import React, { useMemo } from 'react';
 
 function Identicon ({ className = '', publicKey, size, style }: Props): React.ReactElement<Props> {
+  const html = useMemo(
+    () => ({ __html: jdenticon.toSvg(publicKey.substr(2), size) }),
+    [publicKey, size]
+  );
+
   return (
     <div
       className={className}
-      dangerouslySetInnerHTML={{
-        __html: jdenticon.toSvg(publicKey.substr(2), size)
-      }}
+      dangerouslySetInnerHTML={html}
       style={style}
     />
   );

packages/react-identicon/src/icons/Polkadot.tsx

@@ -19,7 +19,7 @@
 import type { Circle } from '@polkadot/ui-shared/icons/types';
 import type { Props } from '../types';
 
-import React from 'react';
+import React, { useMemo } from 'react';
 
 import { polkadotIcon } from '@polkadot/ui-shared';
 
@@ -36,6 +36,11 @@ function renderCircle ({ cx, cy, fill, r }: Circle, key: number): React.ReactNod
 }
 
 function Identicon ({ address, className = '', isAlternative = false, size, style }: Props): React.ReactElement<Props> {
+  const circles = useMemo(
+    () => polkadotIcon(address, { isAlternative }),
+    [address, isAlternative]
+  );
+
   return (
     <svg
       className={className}
@@ -46,7 +51,7 @@ function Identicon ({ address, className = '', isAlternative = false, size, styl
       viewBox='0 0 64 64'
       width={size}
     >
-      {polkadotIcon(address, { isAlternative }).map(renderCircle)}
+      {circles.map(renderCircle)}
     </svg>
   );
 }

packages/reactnative-identicon/src/icons/Polkadot.tsx

@@ -4,7 +4,7 @@
 import type { Circle as CircleType } from '@polkadot/ui-shared/icons/types';
 import type { Props } from '../types';
 
-import React from 'react';
+import React, { useMemo } from 'react';
 import { View } from 'react-native';
 import Svg, { Circle as SvgCircle } from 'react-native-svg';
 
@@ -23,6 +23,11 @@ function renderCircle ({ cx, cy, fill, r }: CircleType, key: number): React.Reac
 }
 
 export default function Identicon ({ address, isAlternative = false, size }: Props): React.ReactElement<Props> {
+  const circles = useMemo(
+    () => polkadotIcon(address, { isAlternative }),
+    [address, isAlternative]
+  );
+
   return (
     <View>
       <Svg
@@ -31,7 +36,7 @@ export default function Identicon ({ address, isAlternative = false, size }: Pro
         viewBox='0 0 64 64'
         width={size}
       >
-        {polkadotIcon(address, { isAlternative }).map(renderCircle)}
+        {circles.map(renderCircle)}
       </Svg>
     </View>
   );

packages/ui-shared/src/icons/polkadot.ts

@@ -22,7 +22,6 @@ const blake2 = (value: Uint8Array): Uint8Array =>
 const S = 64;
 const C = S / 2;
 const Z = S / 64 * 5;
-const ZERO = blake2(new Uint8Array(32));
 
 /* eslint-disable sort-keys */
 const SCHEMA: { [index: string]: Scheme } = {
@@ -43,6 +42,8 @@ const OUTER_CIRCLE: Circle = {
   r: C
 };
 
+let zeroHash: Uint8Array = new Uint8Array();
+
 function getRotation (isSixPoint: boolean): { r: number; ro2: number; r3o4: number; ro4: number; rroot3o2: number; rroot3o4: number } {
   const r = isSixPoint
     ? (C / 8 * 5)
@@ -98,7 +99,11 @@ function findScheme (d: number): Scheme {
 }
 
 function addressToId (address: string): Uint8Array {
-  return blake2(decodeAddress(address)).map((x, i): number => (x + 256 - ZERO[i]) % 256);
+  if (!zeroHash.length) {
+    zeroHash = blake2(new Uint8Array(32));
+  }
+
+  return blake2(decodeAddress(address)).map((x, i) => (x + 256 - zeroHash[i]) % 256);
 }
 
 function getColors (address: string): string[] {
@@ -132,10 +137,19 @@ function getColors (address: string): string[] {
  * @description Generate a array of the circles that make up an identicon
  */
 export function polkadotIcon (address: string, { isAlternative }: Options): Circle[] {
-  const colors = getColors(address);
+  const xy = getCircleXY(isAlternative);
+  let colors: string[];
+
+  try {
+    // in some cases, e.g. RN where crypto may not be initialized, chaos can
+    // happen when hashing, in these cases we just fill with a placeholder
+    colors = getColors(address);
+  } catch {
+    colors = new Array<string>(xy.length).fill('#ddd');
+  }
 
   return [OUTER_CIRCLE].concat(
-    getCircleXY(isAlternative).map(([cx, cy], index): Circle => ({
+    xy.map(([cx, cy], index): Circle => ({
       cx, cy, fill: colors[index], r: Z
     }))
   );