From b4b5f9fc2cd00fa419966dccfc9a9cb3875ab80f Mon Sep 17 00:00:00 2001
From: Anthony LC <anthony.le-courric@mail.numerique.gouv.fr>
Date: Fri, 7 Aug 2026 10:47:49 +0200
Subject: [PATCH] =?UTF-8?q?=E2=9C=85(e2e)=20fix=20flakiness=20with=20langu?=
 =?UTF-8?q?age=20tests?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

When tests were run in parallel, the language tests
could introduce flakiness due to a switch to the
default language not being completed before the
next test started.
---
 .../__tests__/app-impress/language.spec.ts    | 25 ++++++-------------
 .../e2e/__tests__/app-impress/utils-common.ts | 25 +++++++++----------
 2 files changed, 19 insertions(+), 31 deletions(-)

diff --git a/src/frontend/apps/e2e/__tests__/app-impress/language.spec.ts b/src/frontend/apps/e2e/__tests__/app-impress/language.spec.ts
index 51082d147..6dccf90fa 100644
--- a/src/frontend/apps/e2e/__tests__/app-impress/language.spec.ts
+++ b/src/frontend/apps/e2e/__tests__/app-impress/language.spec.ts
@@ -68,14 +68,19 @@ test.describe('Language', () => {
   });
 
   test('can switch language using only keyboard', async ({ page }) => {
-    await waitForLanguageSwitch(page, TestLanguage.English, 'User menu', false);
+    // switch to french
+    await waitForLanguageSwitch(page, TestLanguage.French);
 
-    await page.getByLabel('User menu').click();
+    await page.getByLabel('Menu utilisateur').click();
 
     await page.keyboard.press('Tab');
     await page.keyboard.press('Tab');
     await page.keyboard.press('Enter');
 
+    await expect(
+      page.getByRole('button', { name: 'Déconnexion' }),
+    ).toBeVisible();
+
     await expect(page.getByRole('menuitem', { name: 'English' })).toBeVisible();
     await expect(
       page.getByRole('menuitem', { name: 'Français' }),
@@ -83,22 +88,6 @@ test.describe('Language', () => {
 
     await page.waitForTimeout(300);
 
-    await page.keyboard.press('ArrowDown');
-    await page.keyboard.press('Enter');
-
-    await expect(page.locator('html')).toHaveAttribute('lang', 'fr');
-    await expect(
-      page.getByRole('button', { name: 'Déconnexion' }),
-    ).toBeVisible();
-
-    await page.keyboard.press('Escape');
-
-    await page.getByLabel('Menu utilisateur').click();
-
-    await page.keyboard.press('Tab');
-    await page.keyboard.press('Tab');
-    await page.keyboard.press('Enter');
-    await page.waitForTimeout(300);
     await page.keyboard.press('ArrowDown');
     await page.keyboard.press('ArrowUp');
     await page.keyboard.press('Enter');
diff --git a/src/frontend/apps/e2e/__tests__/app-impress/utils-common.ts b/src/frontend/apps/e2e/__tests__/app-impress/utils-common.ts
index b42785719..dccb9e746 100644
--- a/src/frontend/apps/e2e/__tests__/app-impress/utils-common.ts
+++ b/src/frontend/apps/e2e/__tests__/app-impress/utils-common.ts
@@ -402,20 +402,7 @@ export async function waitForLanguageSwitch(
   page: Page,
   lang: TestLanguageValue,
   labelUserMenu = 'User menu',
-  withMocking = true,
 ) {
-  await page.route(/\**\/api\/v1.0\/users\/\**/, async (route, request) => {
-    if (request.method().includes('PATCH') && withMocking) {
-      await route.fulfill({
-        json: {
-          language: lang.expectedLocale[0],
-        },
-      });
-    } else {
-      await route.continue();
-    }
-  });
-
   await page.getByLabel(labelUserMenu).click();
   const languagePicker = page.getByRole('button', { name: /Language/ });
   const isAlreadyTargetLanguage = await languagePicker
@@ -427,6 +414,18 @@ export async function waitForLanguageSwitch(
     return;
   }
 
+  await page.route(/\**\/api\/v1.0\/users\/\**/, async (route, request) => {
+    if (request.method().includes('PATCH')) {
+      await route.fulfill({
+        json: {
+          language: lang.expectedLocale[0],
+        },
+      });
+    } else {
+      await route.continue();
+    }
+  });
+
   await languagePicker.click();
 
   await page.getByRole('menuitem', { name: lang.label }).click();