fix(auth): never report a completed password change as failed

src/main/services/auth.service.ts

@@ -176,8 +176,18 @@ export class AuthService {
 
       // Only persist when the user opted in - login/logout leave the store empty otherwise,
       // and writing here would put credentials back behind their back.
-      if (configStore.getConfig().rememberMe) {
-        configStore.updateConfig({ password: newPassword });
+      //
+      // Guarded separately from the request, because by this line the password has already
+      // changed on the server. Letting a disk write decide the return value reports a failure
+      // for a change that happened, and the dialog then asks the user to try again with a
+      // current password that is no longer current, so the retry cannot work either. Same
+      // line `resetPassword` draws, and `login.tsx` before it.
+      try {
+        if (configStore.getConfig().rememberMe) {
+          configStore.updateConfig({ password: newPassword });
+        }
+      } catch (err) {
+        console.error('Failed to store the new password after change:', err);
       }
 
       return { success: true };

test/change-password.test.mjs

@@ -0,0 +1,70 @@
+/**
+ * The remember-me write in `changePassword`, and the one way it can misreport.
+ *
+ * By the time that write runs the password has already changed on the server. If a disk
+ * failure is allowed to decide the return value, the user is told the change failed while it
+ * actually went through, and the dialog then asks them to retry with a "current password" that
+ * is no longer current - so the retry fails too, and nothing on screen ever says the change
+ * succeeded. `login.tsx` draws the same line for the same reason, and `resetPassword` was
+ * fixed for it in #103.
+ */
+import { createChecker, loadMain } from './helpers.mjs';
+
+export async function run() {
+  const { check, failures } = createChecker('change-password');
+
+  const { configStore } = await loadMain('store/config.store.js');
+  const { authService } = await loadMain('services/auth.service.js');
+
+  // Stand in for AuthApi. `private` is erased at runtime, so the singleton's client is swappable.
+  let response = {};
+  authService.client = {
+    changePassword: async () => response,
+  };
+
+  response = {};
+
+  configStore.updateConfig({ rememberMe: false, email: '', password: '' });
+  check(
+    'changePassword succeeds without rememberMe',
+    (await authService.changePassword('old', 'brand-new')).success === true
+  );
+  check('no password is written when the user did not opt in', configStore.getConfig().password === '');
+
+  configStore.updateConfig({ rememberMe: true, email: 'a@b.c', password: 'stale' });
+  await authService.changePassword('old', 'brand-new');
+  check(
+    'the stored password is replaced when rememberMe is on',
+    configStore.getConfig().password === 'brand-new'
+  );
+
+  // A rejected change must not touch the store: the old password is still the live one.
+  configStore.updateConfig({ rememberMe: true, email: 'a@b.c', password: 'still-valid' });
+  response = { error: { code: 'BAD_REQUEST', message: 'Current password is incorrect' } };
+  const rejected = await authService.changePassword('wrong', 'never-set');
+  check('a rejected change reports failure', rejected.success === false);
+  check(
+    'a rejected change leaves the stored password alone',
+    configStore.getConfig().password === 'still-valid'
+  );
+
+  // The regression this file exists for.
+  configStore.updateConfig({ rememberMe: true, email: 'a@b.c', password: 'stale' });
+  response = {};
+  const realUpdate = configStore.updateConfig.bind(configStore);
+  configStore.updateConfig = () => {
+    throw new Error('disk full');
+  };
+  let survived;
+  try {
+    survived = await authService.changePassword('old', 'brand-new');
+  } finally {
+    configStore.updateConfig = realUpdate;
+  }
+  check('a change still succeeds when the store write throws', survived.success === true);
+  check('and reports no error', survived.error === undefined);
+
+  configStore.updateConfig({ rememberMe: false, email: '', password: '' });
+
+  return failures;
+}

test/run.mjs

@@ -29,6 +29,7 @@ for (const module of [
   './suggestion-sentinel.test.mjs',
   './suggestion-emphasis.test.mjs',
   './mac-update-util.test.mjs',
+  './change-password.test.mjs',
   './password-reset.test.mjs',
 ]) {
   const { run } = await import(module);