From aad58bceea2a6ccd3e5ae7f689ca868f100c9096 Mon Sep 17 00:00:00 2001
From: Ruihang Xia <waynestxia@gmail.com>
Date: Thu, 7 Mar 2024 17:03:55 +0800
Subject: [PATCH] chore: simplify the return type of `validate_data_types()`

Signed-off-by: Ruihang Xia <waynestxia@gmail.com>
---
 datafusion/functions/src/datetime/common.rs   | 15 +++++++------
 datafusion/functions/src/datetime/to_date.rs  |  4 +---
 .../functions/src/datetime/to_timestamp.rs    | 22 +++++--------------
 3 files changed, 14 insertions(+), 27 deletions(-)

diff --git a/datafusion/functions/src/datetime/common.rs b/datafusion/functions/src/datetime/common.rs
index 829f13b5a0a6..126a74e888a7 100644
--- a/datafusion/functions/src/datetime/common.rs
+++ b/datafusion/functions/src/datetime/common.rs
@@ -38,26 +38,27 @@ pub(crate) fn string_to_timestamp_nanos_shim(s: &str) -> Result<i64> {
     string_to_timestamp_nanos(s).map_err(|e| e.into())
 }
 
-pub(crate) fn validate_data_types(
-    args: &[ColumnarValue],
-    name: &str,
-) -> Option<Result<ColumnarValue>> {
+/// Checks that all the arguments from the second are of type [Utf8] or [LargeUtf8]
+///
+/// [Utf8]: DataType::Utf8
+/// [LargeUtf8]: DataType::LargeUtf8
+pub(crate) fn validate_data_types(args: &[ColumnarValue], name: &str) -> Result<()> {
     for (idx, a) in args.iter().skip(1).enumerate() {
         match a.data_type() {
             DataType::Utf8 | DataType::LargeUtf8 => {
                 // all good
             }
             _ => {
-                return Some(exec_err!(
+                return exec_err!(
                     "{name} function unsupported data type at index {}: {}",
                     idx + 1,
                     a.data_type()
-                ));
+                );
             }
         }
     }
 
-    None
+    Ok(())
 }
 
 /// Accepts a string and parses it using the [`chrono::format::strftime`] specifiers
diff --git a/datafusion/functions/src/datetime/to_date.rs b/datafusion/functions/src/datetime/to_date.rs
index e1b842680ca4..3756566d4204 100644
--- a/datafusion/functions/src/datetime/to_date.rs
+++ b/datafusion/functions/src/datetime/to_date.rs
@@ -95,9 +95,7 @@ impl ScalarUDFImpl for ToDateFunc {
 
         // validate that any args after the first one are Utf8
         if args.len() > 1 {
-            if let Some(value) = validate_data_types(args, "to_date") {
-                return value;
-            }
+            validate_data_types(args, "to_date")?;
         }
 
         match args[0].data_type() {
diff --git a/datafusion/functions/src/datetime/to_timestamp.rs b/datafusion/functions/src/datetime/to_timestamp.rs
index cd8593337c7a..2eb21c5cdaec 100644
--- a/datafusion/functions/src/datetime/to_timestamp.rs
+++ b/datafusion/functions/src/datetime/to_timestamp.rs
@@ -127,9 +127,7 @@ impl ScalarUDFImpl for ToTimestampFunc {
 
         // validate that any args after the first one are Utf8
         if args.len() > 1 {
-            if let Some(value) = validate_data_types(args, "to_timestamp") {
-                return value;
-            }
+            validate_data_types(args, "to_timestamp")?;
         }
 
         match args[0].data_type() {
@@ -179,9 +177,7 @@ impl ScalarUDFImpl for ToTimestampSecondsFunc {
 
         // validate that any args after the first one are Utf8
         if args.len() > 1 {
-            if let Some(value) = validate_data_types(args, "to_timestamp_seconds") {
-                return value;
-            }
+            validate_data_types(args, "to_timestamp")?;
         }
 
         match args[0].data_type() {
@@ -228,9 +224,7 @@ impl ScalarUDFImpl for ToTimestampMillisFunc {
 
         // validate that any args after the first one are Utf8
         if args.len() > 1 {
-            if let Some(value) = validate_data_types(args, "to_timestamp_millis") {
-                return value;
-            }
+            validate_data_types(args, "to_timestamp")?;
         }
 
         match args[0].data_type() {
@@ -277,9 +271,7 @@ impl ScalarUDFImpl for ToTimestampMicrosFunc {
 
         // validate that any args after the first one are Utf8
         if args.len() > 1 {
-            if let Some(value) = validate_data_types(args, "to_timestamp_micros") {
-                return value;
-            }
+            validate_data_types(args, "to_timestamp")?;
         }
 
         match args[0].data_type() {
@@ -326,9 +318,7 @@ impl ScalarUDFImpl for ToTimestampNanosFunc {
 
         // validate that any args after the first one are Utf8
         if args.len() > 1 {
-            if let Some(value) = validate_data_types(args, "to_timestamp_nanos") {
-                return value;
-            }
+            validate_data_types(args, "to_timestamp")?;
         }
 
         match args[0].data_type() {
@@ -391,8 +381,6 @@ mod tests {
     use datafusion_common::{assert_contains, DataFusionError, ScalarValue};
     use datafusion_expr::ScalarFunctionImplementation;
 
-    use crate::datetime::common::string_to_datetime_formatted;
-
     use super::*;
 
     fn to_timestamp(args: &[ColumnarValue]) -> Result<ColumnarValue> {