From c76c9cc1f539a729766a395204f84a20daf34770 Mon Sep 17 00:00:00 2001
From: Daniel Stinson-Diess <dstinson-diess@brex.com>
Date: Wed, 27 Nov 2024 15:44:38 -0600
Subject: [PATCH] fix(message): use correct encodings for JSON Number values

This updates the private setValue helper to conditonally use the
correct float or integer encoding per JSON Number type. Relying on
the gjson Value method can result in imprecise copies which caused
incremented numbers on large integers like the test case added.
---
 message/message.go            |  8 ++++++++
 transform/object_copy_test.go | 30 ++++++++++++++++++++++++++++++
 2 files changed, 38 insertions(+)

diff --git a/message/message.go b/message/message.go
index cc4d9d56..b742597e 100644
--- a/message/message.go
+++ b/message/message.go
@@ -5,6 +5,7 @@ import (
 	"bytes"
 	"encoding/json"
 	"fmt"
+	"math"
 	"strings"
 	"unicode/utf8"
 
@@ -366,6 +367,13 @@ func setValue(json []byte, key string, value interface{}) ([]byte, error) {
 			return sjson.SetBytes(json, key, base64.Encode(v))
 		}
 	case Value:
+		if v.gjson.Type == gjson.Number {
+			if v.Float() == math.Trunc(v.Float()) {
+				return sjson.SetBytes(json, key, v.Int())
+			}
+			return sjson.SetBytes(json, key, v.Float())
+		}
+
 		return sjson.SetBytes(json, key, v.Value())
 	default:
 		return sjson.SetBytes(json, key, v)
diff --git a/transform/object_copy_test.go b/transform/object_copy_test.go
index d979b804..3be75a2f 100644
--- a/transform/object_copy_test.go
+++ b/transform/object_copy_test.go
@@ -32,6 +32,36 @@ var objectCopyTests = []struct {
 			[]byte(`{"a":"b","c":"b"}`),
 		},
 	},
+	{
+		"large integer",
+		config.Config{
+			Settings: map[string]interface{}{
+				"object": map[string]interface{}{
+					"source_key": "a",
+					"target_key": "b",
+				},
+			},
+		},
+		[]byte(`{"a":30400402455622563}`),
+		[][]byte{
+			[]byte(`{"a":30400402455622563,"b":30400402455622563}`),
+		},
+	},
+	{
+		"large float",
+		config.Config{
+			Settings: map[string]interface{}{
+				"object": map[string]interface{}{
+					"source_key": "a",
+					"target_key": "b",
+				},
+			},
+		},
+		[]byte(`{"a":3.141592653589793}`),
+		[][]byte{
+			[]byte(`{"a":3.141592653589793,"b":3.141592653589793}`),
+		},
+	},
 	{
 		"unescape object",
 		config.Config{