From 032bbbbad57b43d7bde3b61a4a0abf16774ace55 Mon Sep 17 00:00:00 2001
From: Chris0Jeky <jeky.tck@gmail.com>
Date: Sun, 6 Sep 2026 05:24:37 +0100
Subject: [PATCH] Unify frontend API root normalization

---
 frontend/taskdeck-web/src/api/versionApi.ts   | 15 +++--------
 .../src/composables/useBoardRealtime.ts       |  5 ++--
 .../src/tests/utils/apiRoot.spec.ts           | 27 +++++++++++++++++++
 frontend/taskdeck-web/src/utils/apiRoot.ts    |  7 +++++
 4 files changed, 40 insertions(+), 14 deletions(-)
 create mode 100644 frontend/taskdeck-web/src/tests/utils/apiRoot.spec.ts
 create mode 100644 frontend/taskdeck-web/src/utils/apiRoot.ts

diff --git a/frontend/taskdeck-web/src/api/versionApi.ts b/frontend/taskdeck-web/src/api/versionApi.ts
index cfaaf5ea0..3e7f29fe8 100644
--- a/frontend/taskdeck-web/src/api/versionApi.ts
+++ b/frontend/taskdeck-web/src/api/versionApi.ts
@@ -1,5 +1,8 @@
 import http from './http'
 import type { RetryableRequestConfig } from './httpRetry'
+import { apiRootFrom } from '../utils/apiRoot'
+
+export { apiRootFrom } from '../utils/apiRoot'
 
 /**
  * Product-version lookup (#1948).
@@ -27,18 +30,6 @@ export interface LiveHealthResponse {
   timestamp?: string
 }
 
-/**
- * Pure derivation of the server root from an API base: strips one trailing
- * `/api` segment, with or without its trailing slash. Split out from
- * `resolveApiRoot()` because `VITE_API_BASE_URL` is inlined at build time —
- * a test can only reach the *rule* through a function that takes the base as
- * an argument, and every deployment shape (`/api`, `/taskdeck/api`, an
- * absolute origin, empty) has to be covered.
- */
-export function apiRootFrom(apiBase: string): string {
-  return apiBase.replace(/\/api\/?$/i, '')
-}
-
 /**
  * Server root for endpoints that sit outside the `/api` prefix. Mirrors
  * `useBoardRealtime.resolveHubUrl()`; returns `''` for the packaged deployment
diff --git a/frontend/taskdeck-web/src/composables/useBoardRealtime.ts b/frontend/taskdeck-web/src/composables/useBoardRealtime.ts
index ab25efec0..05271e4c6 100644
--- a/frontend/taskdeck-web/src/composables/useBoardRealtime.ts
+++ b/frontend/taskdeck-web/src/composables/useBoardRealtime.ts
@@ -8,6 +8,7 @@ import {
 import type { BoardPresenceSnapshot, BoardRealtimeEvent } from '../types/realtime'
 import { getToken } from '../utils/tokenStorage'
 import { logWarn } from '../utils/errorReporting'
+import { apiRootFrom } from '../utils/apiRoot'
 
 const BOARD_MUTATION_EVENT = 'boardMutation'
 const BOARD_PRESENCE_EVENT = 'boardPresence'
@@ -19,9 +20,9 @@ const FALLBACK_POLL_INTERVAL_MS = 30000
 // prevents the ~3 req/s thrash observed with rapid SignalR event bursts.
 const MUTATION_DEBOUNCE_MS = 300
 
-function resolveHubUrl(): string {
+export function resolveHubUrl(): string {
   const apiBase = import.meta.env.VITE_API_BASE_URL || 'http://localhost:5000/api'
-  const apiRoot = apiBase.replace(/\/api\/?$/i, '')
+  const apiRoot = apiRootFrom(apiBase)
   return `${apiRoot}/hubs/boards`
 }
 
diff --git a/frontend/taskdeck-web/src/tests/utils/apiRoot.spec.ts b/frontend/taskdeck-web/src/tests/utils/apiRoot.spec.ts
new file mode 100644
index 000000000..5f02941fd
--- /dev/null
+++ b/frontend/taskdeck-web/src/tests/utils/apiRoot.spec.ts
@@ -0,0 +1,27 @@
+import { describe, expect, it } from 'vitest'
+import { resolveHubUrl } from '../../composables/useBoardRealtime'
+import { apiRootFrom } from '../../utils/apiRoot'
+
+describe('apiRootFrom', () => {
+  it.each([
+    ['', ''],
+    ['/', '/'],
+    ['/api', ''],
+    ['/api/', ''],
+    ['/API/', ''],
+    ['http://localhost:5000/api', 'http://localhost:5000'],
+    ['https://example.test/taskdeck/api/', 'https://example.test/taskdeck'],
+    ['/taskdeck/api', '/taskdeck'],
+    ['/taskdeck/api/', '/taskdeck'],
+    ['/taskdeck/apiary', '/taskdeck/apiary'],
+    ['/taskdeck/api/cards', '/taskdeck/api/cards'],
+    ['https://example.test/api/api', 'https://example.test/api'],
+    ['api', 'api'],
+  ])('normalizes %o to %o', (apiBase, expected) => {
+    expect(apiRootFrom(apiBase)).toBe(expected)
+  })
+
+  it('keeps the realtime hub suffix outside the shared root utility', () => {
+    expect(resolveHubUrl()).toBe('http://localhost:5000/hubs/boards')
+  })
+})
diff --git a/frontend/taskdeck-web/src/utils/apiRoot.ts b/frontend/taskdeck-web/src/utils/apiRoot.ts
new file mode 100644
index 000000000..f500f3f5a
--- /dev/null
+++ b/frontend/taskdeck-web/src/utils/apiRoot.ts
@@ -0,0 +1,7 @@
+/**
+ * Remove exactly one terminal `/api` segment while preserving deployment
+ * subpaths, origins, and unrelated path segments.
+ */
+export function apiRootFrom(apiBase: string): string {
+  return apiBase.replace(/\/api\/?$/i, '')
+}