fix: encode should work with non-UTF-8 binaries (apache#14087)

* fix: encode function should work with strings and binary

closes apache#14055

* chore: address comments, add test

Author: mesejo

datafusion/functions/src/encoding/inner.rs

@@ -87,7 +87,21 @@ impl ScalarUDFImpl for EncodeFunc {
     }
 
     fn return_type(&self, arg_types: &[DataType]) -> Result<DataType> {
-        Ok(arg_types[0].to_owned())
+        use DataType::*;
+
+        Ok(match arg_types[0] {
+            Utf8 => Utf8,
+            LargeUtf8 => LargeUtf8,
+            Utf8View => Utf8,
+            Binary => Utf8,
+            LargeBinary => LargeUtf8,
+            Null => Null,
+            _ => {
+                return plan_err!(
+                    "The encode function can only accept Utf8 or Binary or Null."
+                );
+            }
+        })
     }
 
     fn invoke(&self, args: &[ColumnarValue]) -> Result<ColumnarValue> {
@@ -108,12 +122,12 @@ impl ScalarUDFImpl for EncodeFunc {
         }
 
         match arg_types[0] {
-            DataType::Utf8 | DataType::Binary | DataType::Null => {
+            DataType::Utf8 | DataType::Null => {
                 Ok(vec![DataType::Utf8; 2])
             }
-            DataType::LargeUtf8 | DataType::LargeBinary => {
-                Ok(vec![DataType::LargeUtf8, DataType::Utf8])
-            }
+            DataType::LargeUtf8 => Ok(vec![DataType::LargeUtf8, DataType::Utf8]),
+            DataType::Binary => Ok(vec![DataType::Binary, DataType::Utf8]),
+            DataType::LargeBinary => Ok(vec![DataType::LargeBinary, DataType::Utf8]),
             _ => plan_err!(
                 "1st argument should be Utf8 or Binary or Null, got {:?}",
                 arg_types[0]

datafusion/sqllogictest/test_files/encoding.slt

@@ -23,8 +23,9 @@ CREATE TABLE test(
   hex_field TEXT
 ) as VALUES
   (0, 'abc',  encode('abc', 'base64'), encode('abc', 'hex')),
-  (1, 'qweqwe',    encode('qweqwe', 'base64'), encode('qweqwe', 'hex')),
-  (2, NULL, NULL, NULL)
+  (1, 'qweqwe', encode('qweqwe', 'base64'), encode('qweqwe', 'hex')),
+  (2, NULL, NULL, NULL),
+  (3, X'8f50d3f60eae370ddbf85c86219c55108a350165', encode('8f50d3f60eae370ddbf85c86219c55108a350165', 'base64'), encode('8f50d3f60eae370ddbf85c86219c55108a350165', 'hex'))
 ;
 
 # errors
@@ -43,31 +44,48 @@ select decode(hex_field, 'non_encoding') from test;
 query error
 select to_hex(hex_field) from test;
 
+query error
+select arrow_cast(decode(X'8f50d3f60eae370ddbf85c86219c55108a350165', 'base64'), 'Utf8');
+
 # Arrays tests
 query T
 SELECT encode(bin_field, 'hex') FROM test ORDER BY num;
 ----
 616263
 717765717765
 NULL
+8f50d3f60eae370ddbf85c86219c55108a350165
 
 query T
 SELECT arrow_cast(decode(base64_field, 'base64'), 'Utf8') FROM test ORDER BY num;
 ----
 abc
 qweqwe
 NULL
+8f50d3f60eae370ddbf85c86219c55108a350165
 
 query T
 SELECT arrow_cast(decode(hex_field, 'hex'), 'Utf8') FROM test ORDER BY num;
 ----
 abc
 qweqwe
 NULL
+8f50d3f60eae370ddbf85c86219c55108a350165
 
 query T
 select to_hex(num) from test ORDER BY num;
 ----
 0
 1
 2
+3
+
+query T
+select encode(bin_field, 'base64') FROM test WHERE num = 3;
+----
+j1DT9g6uNw3b+FyGIZxVEIo1AWU
+
+query B
+select decode(encode(bin_field, 'base64'), 'base64') = X'8f50d3f60eae370ddbf85c86219c55108a350165' FROM test WHERE num = 3;
+----
+true