Refactor compose path detection into a reusable utility function and add related tests (#40663)

app/javascript/mastodon/actions/compose.js

@@ -10,6 +10,7 @@ import { tagHistory } from '@/mastodon/settings';
 import { emojiMartSearch } from '@/mastodon/features/emoji/picker';
 
 import { showAlert, showAlertForError } from './alerts';
+import { isStandaloneComposePath } from './compose_path';
 import { emojiUse } from './emojis';
 import { importFetchedAccounts, importFetchedStatus } from './importer';
 import { openModal } from './modal';
@@ -278,7 +279,7 @@ export function submitCompose(successCallback) {
         'Idempotency-Key': getState().getIn(['compose', 'idempotencyKey']),
       },
     }).then(function (response) {
-      if ((browserHistory.location.pathname === '/publish' || browserHistory.location.pathname === '/statuses/new') && window.history.state) {
+      if (isStandaloneComposePath(browserHistory.location.pathname) && window.history.state) {
         browserHistory.goBack();
       }
 

app/javascript/mastodon/actions/compose_path.test.ts

@@ -0,0 +1,35 @@
+import { isStandaloneComposePath } from './compose_path';
+
+describe('isStandaloneComposePath', () => {
+  test('returns true for /publish', () => {
+    expect(isStandaloneComposePath('/publish')).toBe(true);
+  });
+
+  test('returns true for /statuses/new', () => {
+    expect(isStandaloneComposePath('/statuses/new')).toBe(true);
+  });
+
+  test('returns true for /deck/publish', () => {
+    expect(isStandaloneComposePath('/deck/publish')).toBe(true);
+  });
+
+  test('returns true for /deck/statuses/new', () => {
+    expect(isStandaloneComposePath('/deck/statuses/new')).toBe(true);
+  });
+
+  test('returns false for /deck/home', () => {
+    expect(isStandaloneComposePath('/deck/home')).toBe(false);
+  });
+
+  test('returns false for /home', () => {
+    expect(isStandaloneComposePath('/home')).toBe(false);
+  });
+
+  test('returns false for /deck', () => {
+    expect(isStandaloneComposePath('/deck')).toBe(false);
+  });
+
+  test('returns false for /deck/publish/extra', () => {
+    expect(isStandaloneComposePath('/deck/publish/extra')).toBe(false);
+  });
+});

app/javascript/mastodon/actions/compose_path.ts

@@ -0,0 +1,7 @@
+export function isStandaloneComposePath(pathname: string): boolean {
+  const normalized = pathname.startsWith('/deck/')
+    ? pathname.slice('/deck'.length)
+    : pathname;
+
+  return normalized === '/publish' || normalized === '/statuses/new';
+}