From 204b0ed25950162df36b130b1d668409b096f691 Mon Sep 17 00:00:00 2001
From: laurenceisla <lau.isla.c@gmail.com>
Date: Tue, 20 Jul 2021 16:40:45 -0500
Subject: [PATCH] Add improved error messages for RPC on a stale schema

Error message for a not found RPC.

Unsupported overloaded RPC with the same argument names but different types.
---
 api.rst               |  4 ++++
 releases/upcoming.rst |  4 ++++
 schema_cache.rst      | 14 +++++++-------
 3 files changed, 15 insertions(+), 7 deletions(-)

diff --git a/api.rst b/api.rst
index 735aa2940..2dea57d3f 100644
--- a/api.rst
+++ b/api.rst
@@ -1346,6 +1346,10 @@ You can call overloaded functions with different number of arguments.
 
   GET /rpc/rental_duration?customer_id=232&from_date=2018-07-01 HTTP/1.1
 
+.. important::
+
+  Overloaded functions with the same argument names but different types are not supported.
+
 .. _binary_output:
 
 Binary Output
diff --git a/releases/upcoming.rst b/releases/upcoming.rst
index 398370f05..cfebed6d2 100644
--- a/releases/upcoming.rst
+++ b/releases/upcoming.rst
@@ -37,3 +37,7 @@ Changed
 * Docker images are now optimized to be built from the scratch image. This reduces the compressed image size from over 30 MB to about 4 MB.
   For more details, see `Docker image built with Nix <https://github.com/PostgREST/postgrest/tree/main/nix/tools/docker#user-content-docker-image-built-with-nix>`_.
   |br| -- `@monacoremo <https://github.com/monacoremo>`_
+
+* Improved error message for a not found RPC on a stale schema (see :ref:`stale_function_signature`) and for the unsupported case of
+  overloaded functions with the same argument names but different types.
+  |br| -- `@laurenceisla <https://github.com/laurenceisla>`_
diff --git a/schema_cache.rst b/schema_cache.rst
index a57cf83f3..9e994c75e 100644
--- a/schema_cache.rst
+++ b/schema_cache.rst
@@ -53,6 +53,8 @@ But instead, you get an error message that looks like this:
 
 As you can see, PostgREST couldn't find the newly created foreign key in the schema cache. See the section :ref:`schema_reloading` to solve this issue.
 
+.. _stale_function_signature:
+
 Stale Function Signature
 ~~~~~~~~~~~~~~~~~~~~~~~~
 
@@ -71,16 +73,14 @@ Then, you make this request:
 
   GET /rpc/plus_one?num=1 HTTP/1.1
 
-On a stale schema, PostgREST will assume :code:`text` as the default type for the function argument ``num``. Thus, the response you get is:
+Next, PostgREST tries to find the function on the stale schema to no avail:
 
 .. code-block:: json
 
- {
-  "hint":"No function matches the given name and argument types. You might need to add explicit type casts.",
-  "details":null,
-  "code":"42883",
-  "message":"function test.plus_one(num => text) does not exist"
- }
+  {
+    "hint": "If a new function was created in the database with this name and arguments, try reloading the schema cache.",
+    "message": "Could not find the api.plus_one(num) function in the schema cache"
+  }
 
 See the section :ref:`schema_reloading` to solve this issue.