Add basic regex validation for addresses to frontend.

frontend/client/modules/create/utils.ts

@@ -1,6 +1,6 @@
 import { ProposalDraft, CreateMilestone, STATUS } from 'types';
 import { User } from 'types';
-import { getAmountError } from 'utils/validators';
+import { getAmountError, isValidAddress } from 'utils/validators';
 import { MILESTONE_STATE, Proposal } from 'types';
 import { Zat, toZat } from 'utils/units';
 import { ONE_DAY } from 'utils/time';
@@ -81,7 +81,7 @@ export function getCreateErrors(
   }
 
   // Payout address
-  if (!payoutAddress) {
+  if (payoutAddress && !isValidAddress(payoutAddress)) {
     errors.payoutAddress = 'That doesn’t look like a valid address';
   }
 

frontend/client/utils/validators.ts

@@ -17,7 +17,19 @@ export function isValidEmail(email: string): boolean {
   return /\S+@\S+\.\S+/.test(email);
 }
 
+// Uses simple regex to validate addresses, doesn't check checksum or network
 export function isValidAddress(address: string): boolean {
-  console.warn('TODO - implement utils.isValidAddress', address);
-  return true;
+  // T address
+  if (/^t[a-zA-Z0-9]{34}$/.test(address)) {
+    return true;
+  }
+  // Sprout address
+  if (/^z?[a-zA-Z0-9]{94}$/.test(address)) {
+    return true;
+  }
+  // Sapling address
+  if (/^z(s)?(reg)?(testsapling)?[a-zA-Z0-9]{76}$/.test(address)) {
+    return true;
+  }
+  return false;
 }