From c767dca9df19bf0d92f1f66edbbdefb3fab62adb Mon Sep 17 00:00:00 2001
From: Robin Tang <rtang.cs@gmail.com>
Date: Thu, 26 Sep 2024 10:41:23 -0700
Subject: [PATCH] WIP.

---
 clients/redshift/cast.go      |  8 ++++++++
 clients/redshift/cast_test.go | 29 +++++++++++++++++++++++++++++
 2 files changed, 37 insertions(+)

diff --git a/clients/redshift/cast.go b/clients/redshift/cast.go
index 52af74d7f..22cf1be98 100644
--- a/clients/redshift/cast.go
+++ b/clients/redshift/cast.go
@@ -10,6 +10,14 @@ import (
 
 const maxRedshiftLength int32 = 65535
 
+func canIncreasePrecision(colKind typing.KindDetails) bool {
+	if colKind.Kind == typing.String.Kind && colKind.OptionalStringPrecision != nil {
+		return maxRedshiftLength > *colKind.OptionalStringPrecision
+	}
+
+	return false
+}
+
 func replaceExceededValues(colVal string, colKind typing.KindDetails, truncateExceededValue bool) string {
 	if colKind.Kind == typing.Struct.Kind || colKind.Kind == typing.String.Kind {
 		maxLength := maxRedshiftLength
diff --git a/clients/redshift/cast_test.go b/clients/redshift/cast_test.go
index 7867e164f..abe30773a 100644
--- a/clients/redshift/cast_test.go
+++ b/clients/redshift/cast_test.go
@@ -11,6 +11,35 @@ import (
 	"github.com/stretchr/testify/assert"
 )
 
+func (r *RedshiftTestSuite) TestCanIncreasePrecision() {
+	{
+		// Not a string
+		assert.False(r.T(), canIncreasePrecision(typing.Struct))
+	}
+	{
+		// String, but precision is not specified
+		assert.False(r.T(), canIncreasePrecision(typing.String))
+	}
+	{
+		// String, but maxed out already
+		assert.False(r.T(), canIncreasePrecision(
+			typing.KindDetails{
+				Kind:                    typing.String.Kind,
+				OptionalStringPrecision: typing.ToPtr(maxRedshiftLength),
+			}),
+		)
+	}
+	{
+		// String, precision is low and can be increased
+		assert.True(r.T(), canIncreasePrecision(
+			typing.KindDetails{
+				Kind:                    typing.String.Kind,
+				OptionalStringPrecision: typing.ToPtr(maxRedshiftLength - 1),
+			}),
+		)
+	}
+}
+
 func (r *RedshiftTestSuite) TestReplaceExceededValues() {
 	{
 		// Irrelevant data type