✨(build) add cache-busting source version in build

Author: sylvinus

.github/workflows/messages-ghcr.yml

@@ -100,6 +100,12 @@ jobs:
       context: "src/frontend"
       target: runtime-prod
       arm64_reuse_amd64_build_arg: "FRONTEND_IMAGE"
+      # Bakes the commit SHA into the build as the asset cache-buster
+      # (vite.config.ts → __SOURCE_VERSION__); without it the build falls back to a
+      # timestamp. The src/frontend context ships no .git, so this is the only
+      # way the image gets the real SHA. SOURCE_VERSION matches the var name
+      # Scalingo's buildpack sets natively, so both deploy paths agree.
+      build_args: "SOURCE_VERSION=${{ github.sha }}"
 
   docker-publish-backend:
     needs: docker-publish-python-uv

src/frontend/Dockerfile

@@ -41,6 +41,13 @@ COPY --chown=${DOCKER_USER} . ./
 ARG API_ORIGIN
 ENV NEXT_PUBLIC_API_ORIGIN=${API_ORIGIN}
 
+# Commit SHA (or any per-deploy version) baked in as the asset cache-buster —
+# see vite.config.ts. Named SOURCE_VERSION to match the var Scalingo's buildpack
+# sets natively. Pass `--build-arg SOURCE_VERSION=$(git rev-parse --short HEAD)`;
+# if omitted the build falls back to a timestamp (still unique per deploy).
+ARG SOURCE_VERSION
+ENV SOURCE_VERSION=${SOURCE_VERSION}
+
 RUN npm run build
 
 # Normalize output path to /app (matches the runtime-prod layout)

src/frontend/caddy/Caddyfile

@@ -47,6 +47,17 @@
 			header_up X-Forwarded-For {remote_host}
 		}
 
+		# --- Cache policy for the static SPA output ---
+		# Vite fingerprints everything under /assets, so a given URL's bytes
+		# never change: cache it forever. A new deploy emits new hashed URLs.
+		@immutable path /assets/*
+		header @immutable Cache-Control "public, max-age=31536000, immutable"
+		# The SPA shell and other non-fingerprinted files (index.html, the
+		# /locales JSON, images) must revalidate every load, or a deploy's new
+		# asset hashes / translations only show up after a manual hard refresh.
+		@revalidate not path /assets/*
+		header @revalidate Cache-Control "no-cache"
+
 		# SPA fallback: any unmatched request returns index.html so the
 		# client-side router can resolve the path.
 		try_files {path} /index.html

src/frontend/public/locales/common/fr-FR.json

@@ -332,9 +332,9 @@
   "Check DNS again": "Revérifier les DNS",
   "Check for new mail regularly": "Synchroniser ce compte régulièrement",
   "Checking DNS records...": "Vérification des enregistrements DNS...",
-  "Checking every {{count}} min_one": "Synchronisation toutes les {{count}} min",
-  "Checking every {{count}} min_many": "Synchronisation toutes les {{count}} min",
-  "Checking every {{count}} min_other": "Synchronisation toutes les {{count}} min",
+  "Checking every {{count}} min_one": "Synchro toutes les {{count}} min",
+  "Checking every {{count}} min_many": "Synchro toutes les {{count}} min",
+  "Checking every {{count}} min_other": "Synchro toutes les {{count}} min",
   "Choose calendar": "Choisir l'agenda",
   "Choose the type of integration you want to create": "Choisissez le type d'intégration que vous souhaitez créer",
   "Clear filters": "Retirer les filtres",

src/frontend/src/features/i18n/initI18n.ts

@@ -43,6 +43,10 @@ export const initI18n = (config: AppConfig) => {
       returnEmptyString: false,
       backend: {
         loadPath: "/locales/{{ns}}/{{lng}}.json",
+        // Cache-bust the static locale files on every deploy: their URLs are
+        // otherwise fixed, so a CDN/browser keeps serving a stale copy and any
+        // newly added translation falls back to English (a half-translated UI).
+        queryStringParams: { v: __SOURCE_VERSION__ },
       }
     })
     .catch((error) => {

src/frontend/src/vite-env.d.ts

@@ -44,3 +44,7 @@ interface ImportMetaEnv {
 interface ImportMeta {
   readonly env: ImportMetaEnv;
 }
+
+// Per-build version stamp injected by Vite (see vite.config.ts `define`). Used
+// to cache-bust runtime-loaded assets such as the locale JSON files.
+declare const __SOURCE_VERSION__: string;

src/frontend/vite.config.ts

@@ -1,3 +1,4 @@
+import { execSync } from 'node:child_process';
 import { defineConfig, type Plugin } from 'vite';
 import react from '@vitejs/plugin-react';
 import legacy from '@vitejs/plugin-legacy';
@@ -10,8 +11,32 @@ import pkg from './package.json';
 // Single source of truth for supported browsers; drives which polyfills the
 // legacy plugin injects (see the `legacy` plugin below).
 const browserslist = pkg.browserslist;
+// A per-build version stamp, baked in as `__SOURCE_VERSION__`. Used to cache-bust
+// the runtime-fetched locale JSONs (their URLs are otherwise fixed, so a CDN /
+// browser keeps serving a stale copy after a deploy — a half-translated UI).
+// Resolution order, most authoritative first:
+//   - SOURCE_VERSION   commit SHA — injected by Scalingo's buildpack natively,
+//                      and passed as a build-arg from our CI Docker build
+//   - `git`            local builds / any context that ships the .git dir
+//   - timestamp        last-resort, still unique from one deploy to the next
+const appVersion =
+  process.env.SOURCE_VERSION ||
+  (() => {
+    try {
+      return execSync('git rev-parse --short HEAD', {
+        stdio: ['ignore', 'pipe', 'ignore'],
+      })
+        .toString()
+        .trim();
+    } catch {
+      return `t${Date.now()}`;
+    }
+  })();
 
 export default defineConfig({
+  define: {
+    __SOURCE_VERSION__: JSON.stringify(appVersion),
+  },
   plugins: [
     // See ./tsr.config.json for tanstackRouter config
     tanstackRouter(),