settings/tokens: Delete plaintext tokens from memory after leaving API tokens settings page

app/routes/settings/tokens.js

@@ -11,4 +11,16 @@ export default class TokenSettingsRoute extends AuthenticatedRoute {
     let apiTokens = await this.store.findAll('api-token');
     return TrackedArray.from(apiTokens.slice());
   }
+
+  /**
+   * Ensure that all plaintext tokens are deleted from memory after leaving
+   * the API tokens settings page.
+   */
+  resetController(controller) {
+    for (let token of controller.model) {
+      if (token.token) {
+        token.token = undefined;
+      }
+    }
+  }
 }

tests/acceptance/api-token-test.js

@@ -133,6 +133,25 @@ module('Acceptance | api-tokens', function (hooks) {
     assert.dom('[data-test-token]').hasText(token.token);
   });
 
+  test('API tokens are only visible in plaintext until the page is left', async function (assert) {
+    prepare(this);
+
+    await visit('/settings/tokens');
+    await click('[data-test-new-token-button]');
+    await fillIn('[data-test-focused-input]', 'the new token');
+    await click('[data-test-save-token-button]');
+
+    let token = this.server.schema.apiTokens.findBy({ name: 'the new token' });
+    assert.dom('[data-test-token]').hasText(token.token);
+
+    // leave the API tokens page
+    await visit('/settings');
+
+    // and visit it again
+    await visit('/settings/tokens');
+    assert.dom('[data-test-token]').doesNotExist();
+  });
+
   test('navigating away while creating a token does not keep it in the list', async function (assert) {
     prepare(this);