From 95cd7fee33f1fd928f9f926ae38128cb19547233 Mon Sep 17 00:00:00 2001
From: Robin Tang <rtang.cs@gmail.com>
Date: Tue, 27 Aug 2024 10:58:31 -0700
Subject: [PATCH] [Debezium] Adding String / UUID passthrough converter (#854)

---
 clients/shared/default_value.go        |  3 +--
 lib/debezium/converters/string.go      | 18 ++++++++++++++++++
 lib/debezium/converters/string_test.go | 21 +++++++++++++++++++++
 lib/debezium/schema.go                 |  2 ++
 lib/debezium/schema_test.go            |  5 +++++
 5 files changed, 47 insertions(+), 2 deletions(-)
 create mode 100644 lib/debezium/converters/string.go
 create mode 100644 lib/debezium/converters/string_test.go

diff --git a/clients/shared/default_value.go b/clients/shared/default_value.go
index 8883c78cc..41ab38cab 100644
--- a/clients/shared/default_value.go
+++ b/clients/shared/default_value.go
@@ -80,8 +80,7 @@ func BackfillColumn(dwh destination.DataWarehouse, column columns.Column, tableI
 		slog.String("table", tableID.FullyQualifiedName()),
 	)
 
-	_, err = dwh.Exec(query)
-	if err != nil {
+	if _, err = dwh.Exec(query); err != nil {
 		return fmt.Errorf("failed to backfill, err: %w, query: %v", err, query)
 	}
 
diff --git a/lib/debezium/converters/string.go b/lib/debezium/converters/string.go
new file mode 100644
index 000000000..2d591a78d
--- /dev/null
+++ b/lib/debezium/converters/string.go
@@ -0,0 +1,18 @@
+package converters
+
+import "github.com/artie-labs/transfer/lib/typing"
+
+type StringPassthrough struct{}
+
+func (StringPassthrough) Convert(value any) (any, error) {
+	castedValue, err := typing.AssertType[string](value)
+	if err != nil {
+		return nil, err
+	}
+
+	return castedValue, nil
+}
+
+func (StringPassthrough) ToKindDetails() typing.KindDetails {
+	return typing.String
+}
diff --git a/lib/debezium/converters/string_test.go b/lib/debezium/converters/string_test.go
new file mode 100644
index 000000000..7ac624670
--- /dev/null
+++ b/lib/debezium/converters/string_test.go
@@ -0,0 +1,21 @@
+package converters
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestStringPassthrough_Convert(t *testing.T) {
+	{
+		// Non string
+		_, err := StringPassthrough{}.Convert(1)
+		assert.ErrorContains(t, err, "expected type string, got int")
+	}
+	{
+		// String
+		value, err := StringPassthrough{}.Convert("test")
+		assert.Nil(t, err)
+		assert.Equal(t, "test", value)
+	}
+}
diff --git a/lib/debezium/schema.go b/lib/debezium/schema.go
index 2453f6066..542efd4ca 100644
--- a/lib/debezium/schema.go
+++ b/lib/debezium/schema.go
@@ -82,6 +82,8 @@ func (f Field) GetScaleAndPrecision() (int32, *int32, error) {
 
 func (f Field) ToValueConverter() converters.ValueConverter {
 	switch f.DebeziumType {
+	case UUID:
+		return converters.StringPassthrough{}
 	case DateTimeWithTimezone:
 		return converters.DateTimeWithTimezone{}
 	case TimeWithTimezone:
diff --git a/lib/debezium/schema_test.go b/lib/debezium/schema_test.go
index e7c74f462..939def9d5 100644
--- a/lib/debezium/schema_test.go
+++ b/lib/debezium/schema_test.go
@@ -271,6 +271,11 @@ func TestField_ToKindDetails(t *testing.T) {
 			},
 			expectedKindDetails: typing.Struct,
 		},
+		{
+			name:                "UUID",
+			field:               Field{DebeziumType: UUID, Type: String},
+			expectedKindDetails: typing.String,
+		},
 	}
 
 	for _, tc := range tcs {