From fd567c7d1f3127e40905ab5bc5ff4f15f571c759 Mon Sep 17 00:00:00 2001
From: Ben Wilson <benwilson512@gmail.com>
Date: Tue, 19 Jan 2021 22:28:51 -0500
Subject: [PATCH] Improved serialization failure messages (#1033)

* improved error messages on serialization failure

* tweak wording

* changelog entry
---
 CHANGELOG.md                          |  4 ++++
 lib/absinthe/phase/document/result.ex | 14 +++++++++++++-
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index b71f5a7e7c..acfa8fc4fd 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,9 @@
 # Changelog
 
+## 1.6.1
+
+- Feature: [Improved serialization failure messages](https://github.com/absinthe-graphql/absinthe/pull/1033)
+
 ## 1.6.0
 
 - Feature: [Interfaces can now implement Interfaces](https://github.com/absinthe-graphql/absinthe/pull/1012), matching the latest spec
diff --git a/lib/absinthe/phase/document/result.ex b/lib/absinthe/phase/document/result.ex
index ec6a776e9d..6fe940b393 100644
--- a/lib/absinthe/phase/document/result.ex
+++ b/lib/absinthe/phase/document/result.ex
@@ -51,7 +51,19 @@ defmodule Absinthe.Phase.Document.Result do
     value =
       case Type.unwrap(emitter.schema_node.type) do
         %Type.Scalar{} = schema_node ->
-          Type.Scalar.serialize(schema_node, value)
+          try do
+            Type.Scalar.serialize(schema_node, value)
+          rescue
+            Absinthe.SerializationError ->
+              raise(Absinthe.SerializationError, """
+              Could not serialize term #{inspect(value)} as type #{schema_node.name}
+
+              When serializing the field:
+              #{emitter.parent_type.name}.#{emitter.schema_node.name} (#{
+                emitter.schema_node.__reference__.location.file
+              }:#{emitter.schema_node.__reference__.location.line})
+              """)
+          end
 
         %Type.Enum{} = schema_node ->
           Type.Enum.serialize(schema_node, value)