fix(front): resolve initialization race condition

Part-of: <https://dev.funkwhale.audio/funkwhale/funkwhale/-/merge_requests/2534>

changes/changelog.d/resolve-axios-race-condition.bugfix

@@ -0,0 +1,2 @@
+Resolve race condition regarding axios when initializing the frontend
+Prevent sending same language setting to backend multiple times

front/src/main.ts

@@ -1,4 +1,4 @@
-import type { InitModule } from '~/types'
+import type { InitModule, InitModuleContext } from '~/types'
 
 import store, { key } from '~/store'
 import router from '~/router'
@@ -22,6 +22,7 @@ const app = createApp({
   data: () => ({ ready: false }),
   mounted () {
     this.ready = true
+    logger.info('Everything loaded!')
   },
   render () {
     if (this.ready) {
@@ -35,19 +36,35 @@ const app = createApp({
 app.use(router)
 app.use(store, key)
 
-const modules: Array<void | Promise<void>> = []
-for (const module of Object.values(import.meta.glob('./init/*.ts', { eager: true })) as { install?: InitModule }[]) {
-  modules.push(module.install?.({
-    app,
-    router,
-    store
-  }))
+const modules: Record<string | 'axios', { install?: InitModule }> = import.meta.glob('./init/*.ts', { eager: true })
+const moduleContext: InitModuleContext = {
+  app,
+  router,
+  store
 }
 
-// Wait for all modules to load
-Promise.all(modules).finally(() => {
-  app.mount('#app')
-  logger.info('Everything loaded!')
-})
+// NOTE: Other modules may depend on network requests and we need to ensure
+//       that all axios interceptors are set before any requests are made
+//       and that the instance url is set before any requests are made
+const IMPORTANT_MODULES_QUEUE = ['axios', 'instance']
+const waitForImportantModules = async () => {
+  for (const moduleName of IMPORTANT_MODULES_QUEUE) {
+    const path = `./init/${moduleName}.ts`
+    if (!(path in modules)) {
+      logger.error(`Failed to load important module: ${path}`)
+      continue
+    }
+
+    await modules[path].install?.(moduleContext)
+    delete modules[path]
+  }
+}
+
+waitForImportantModules()
+  // NOTE: We load the modules in parallel
+  .then(() => Promise.all(Object.values(modules).map(module => module.install?.(moduleContext))))
+  .catch(error => logger.error('Failed to load modules:', error))
+  // NOTE: We need to mount the app after all modules are loaded
+  .finally(() => app.mount('#app'))
 
 // TODO (wvffle): Rename filters from useSharedLabels to filters from backend