From 0dbf63c6a92599cba5b92e0ceea24d66a5986e18 Mon Sep 17 00:00:00 2001
From: Dmitry Olshansky <olshanskydr@gmail.com>
Date: Wed, 14 Aug 2024 13:45:24 +0300
Subject: [PATCH] Add instance HasOpenApi (EmptyAPI :> api)

---
 src/Servant/OpenApi/Internal.hs | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/Servant/OpenApi/Internal.hs b/src/Servant/OpenApi/Internal.hs
index 7551058..92f6912 100644
--- a/src/Servant/OpenApi/Internal.hs
+++ b/src/Servant/OpenApi/Internal.hs
@@ -86,6 +86,10 @@ instance HasOpenApi Raw where
 instance HasOpenApi EmptyAPI where
   toOpenApi _ = mempty
 
+-- | Ignore @'EmptyAPI'@ as part of route in server handlers.
+instance HasOpenApi api => HasOpenApi (EmptyAPI :> api) where
+  toOpenApi _ = toOpenApi (Proxy @api)
+
 -- | All operations of sub API.
 -- This is similar to @'operationsOf'@ but ensures that operations
 -- indeed belong to the API at compile time.