init

app/middleware/force_json_response_middleware.ts

@@ -0,0 +1,16 @@
+import type { HttpContext } from '@adonisjs/core/http'
+import type { NextFn } from '@adonisjs/core/types/http'
+
+/**
+ * Updating the "Accept" header to always accept "application/json" response
+ * from the server. This will force the internals of the framework like
+ * validator errors or auth errors to return a JSON response.
+ */
+export default class ForceJsonResponseMiddleware {
+  async handle({ request }: HttpContext, next: NextFn) {
+    const headers = request.headers()
+    headers.accept = 'application/json'
+
+    return next()
+  }
+}