fix: enable Save button on Add Contact page for address input (#26155)

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## **Description**

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This patches an issue in `add-contact.component.js` where the disabled
state of the `Save` button would disappear only after a successful ENS
resolution, effectively preventing plain addresses to be entered.
I also added some extra unit tests to check for some of the cases that
weren't covered before.

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## **Related issues**

fixes #25918
fixes #25889

## **Manual testing steps**

1. Go to Settings > Contacts > Add Contact
2. Enter a name and a valid Ethereum address
3. Observe the Save button getting enabled
4. Edit the address to make it invalid, observe the Save button getting
disabled
5. Instead of an address, enter an ENS name and pick the resolved result
6. Observe the Save button getting enabled
7. Observe that the input is still editable (repeat 4.)

## **Screenshots/Recordings**

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before and after of your change. -->

### **Before**

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### **After**

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## **Pre-merge author checklist**

- [X] I've followed [MetaMask Contributor
Docs](https://github.com/MetaMask/contributor-docs) and [MetaMask
Extension Coding
Standards](https://github.com/MetaMask/metamask-extension/blob/develop/.github/guidelines/CODING_GUIDELINES.md).
- [X] I've completed the PR template to the best of my ability
- [X] I’ve included tests if applicable
- [ ] I’ve documented my code using [JSDoc](https://jsdoc.app/) format
if applicable
- [ ] I’ve applied the right labels on the PR (see [labeling
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Not required for external contributors.

## **Pre-merge reviewer checklist**

- [ ] I've manually tested the PR (e.g. pull and build branch, run the
app, test code being changed).
- [ ] I confirm that this PR addresses all acceptance criteria described
in the ticket it closes and includes the necessary testing evidence such
as recordings and or screenshots.

---------

Signed-off-by: Mircea Nistor <mirceanis@gmail.com>

ui/pages/settings/contact-list-tab/add-contact/add-contact.component.js

@@ -3,15 +3,15 @@ import PropTypes from 'prop-types';
 import { debounce } from 'lodash';
 import TextField from '../../../../components/ui/text-field';
 import { CONTACT_LIST_ROUTE } from '../../../../helpers/constants/routes';
-import { IS_FLASK, isValidDomainName } from '../../../../helpers/utils/util';
+import { isValidDomainName } from '../../../../helpers/utils/util';
 import DomainInput from '../../../confirmations/send/send-content/add-recipient/domain-input';
 import PageContainerFooter from '../../../../components/ui/page-container/page-container-footer';
 import {
   isBurnAddress,
   isValidHexAddress,
 } from '../../../../../shared/modules/hexstring-utils';
 import { INVALID_RECIPIENT_ADDRESS_ERROR } from '../../../confirmations/send/send.constants';
-import { DomainInputResolutionCell } from '../../../../components/multichain/pages/send/components/domain-input-resolution-cell';
+import { DomainInputResolutionCell } from '../../../../components/multichain/pages/send/components';
 
 export default class AddContact extends PureComponent {
   static contextTypes = {
@@ -68,8 +68,10 @@ export default class AddContact extends PureComponent {
       isValidHexAddress(input, { mixedCaseUseChecksum: true });
     const validEnsAddress = isValidDomainName(input);
 
-    if (!IS_FLASK && !validEnsAddress && !valid) {
+    if (!validEnsAddress && !valid) {
       this.setState({ error: INVALID_RECIPIENT_ADDRESS_ERROR });
+    } else {
+      this.setState({ error: null });
     }
   };
 
@@ -104,6 +106,10 @@ export default class AddContact extends PureComponent {
       this.props;
 
     const errorToRender = domainError || this.state.error;
+    const newAddress = this.state.selectedAddress || this.state.input;
+    const validAddress =
+      !isBurnAddress(newAddress) &&
+      isValidHexAddress(newAddress, { mixedCaseUseChecksum: true });
 
     return (
       <div className="settings-page__content-row address-book__add-contact">
@@ -150,7 +156,7 @@ export default class AddContact extends PureComponent {
                     domainName={addressBookEntryName ?? domainName}
                     onClick={() => {
                       this.setState({
-                        selectedAddress: resolvedAddress,
+                        input: resolvedAddress,
                         newName: this.state.newName || domainName,
                       });
                       this.props.resetDomainResolution();
@@ -171,15 +177,10 @@ export default class AddContact extends PureComponent {
         <PageContainerFooter
           cancelText={this.context.t('cancel')}
           disabled={Boolean(
-            this.state.error ||
-              !this.state.selectedAddress ||
-              !this.state.newName.trim(),
+            this.state.error || !validAddress || !this.state.newName.trim(),
           )}
           onSubmit={async () => {
-            await addToAddressBook(
-              this.state.selectedAddress,
-              this.state.newName,
-            );
+            await addToAddressBook(newAddress, this.state.newName);
             history.push(CONTACT_LIST_ROUTE);
           }}
           onCancel={() => {

ui/pages/settings/contact-list-tab/add-contact/add-contact.test.js

@@ -47,7 +47,7 @@ describe('AddContact component', () => {
     fireEvent.change(input, { target: { value: 'invalid address' } });
     setTimeout(() => {
       expect(getByText('Recipient address is invalid')).toBeInTheDocument();
-    }, 100);
+    }, 600);
   });
 
   it('should get disabled submit button when username field is empty', () => {
@@ -60,4 +60,47 @@ describe('AddContact component', () => {
     const saveButton = getByText('Save');
     expect(saveButton).toBeDisabled();
   });
+
+  it('should enable submit button when input is valid', () => {
+    const store = configureMockStore(middleware)(state);
+    const { getByText, getByTestId } = renderWithProvider(
+      <AddContact {...props} />,
+      store,
+    );
+
+    const nameInput = document.getElementById('nickname');
+    fireEvent.change(nameInput, { target: { value: 'friend' } });
+
+    const addressInput = getByTestId('ens-input');
+    fireEvent.change(addressInput, {
+      target: { value: '0x1234Bf0BBa69C63E2657cF94693cC4A907085678' },
+    });
+
+    const saveButton = getByText('Save');
+    expect(saveButton).not.toBeDisabled();
+  });
+
+  it('should disable submit button when input is not a valid address', () => {
+    const store = configureMockStore(middleware)(state);
+    const { getByText, getByTestId } = renderWithProvider(
+      <AddContact {...props} />,
+      store,
+    );
+
+    const nameInput = document.getElementById('nickname');
+    fireEvent.change(nameInput, { target: { value: 'friend' } });
+
+    const addressInput = getByTestId('ens-input');
+    fireEvent.change(addressInput, {
+      // invalid length
+      target: { value: '0x1234' },
+    });
+    expect(getByText('Save')).toBeDisabled();
+
+    fireEvent.change(addressInput, {
+      // wrong checksum
+      target: { value: '0x1234bf0bba69C63E2657cF94693cC4A907085678' },
+    });
+    expect(getByText('Save')).toBeDisabled();
+  });
 });