SNOW-1830541 Decoder functionality for functions1.test and functions2.test (#2881)

1. Which Jira issue is this PR addressing? Make sure that there is an
accompanying issue to your PR.

   Fixes SNOW-1830541

2. Fill out the following pre-review checklist:

- [ ] I am adding a new automated test(s) to verify correctness of my
new code
- [ ] If this test skips Local Testing mode, I'm requesting review from
@snowflakedb/local-testing
   - [ ] I am adding new logging messages
   - [ ] I am adding a new telemetry message
   - [ ] I am adding new credentials
   - [ ] I am adding a new dependency
- [ ] If this is a new feature/behavior, I'm adding the Local Testing
parity changes.
- [x] I acknowledge that I have ensured my changes to be thread-safe.
Follow the link for more information: [Thread-safe Developer
Guidelines](https://github.com/snowflakedb/snowpark-python/blob/main/CONTRIBUTING.md#thread-safe-development)

3. Please describe how your code solves the related issue.

Minor changes to the decoder to make functions1.test and functions2.test
work.

Author: sfc-gh-vbudati

src/snowflake/snowpark/_internal/proto/ast.proto

@@ -22,6 +22,10 @@ message List_SpDataType {
   repeated SpDataType list = 1;
 }
 
+message List_SpStructField {
+  repeated SpStructField list = 1;
+}
+
 message List_String {
   repeated string list = 1;
 }
@@ -174,7 +178,7 @@ message SpStructField {
 
 // sp-type.ir:46
 message SpStructType {
-  repeated SpStructField fields = 1;
+  List_SpStructField fields = 1;
   bool structured = 2;
 }
 

tests/ast/decoder.py

@@ -1,5 +1,5 @@
 #
-# Copyright (c) 2012-2024 Snowflake Computing Inc. All rights reserved.
+# Copyright (c) 2012-2025 Snowflake Computing Inc. All rights reserved.
 #
 
 import logging
@@ -12,7 +12,7 @@
 
 from google.protobuf.json_format import MessageToDict
 
-from build.lib.snowflake.snowpark.relational_grouped_dataframe import GroupingSets
+from snowflake.snowpark.relational_grouped_dataframe import GroupingSets
 from snowflake.snowpark import Session, Column, DataFrameAnalyticsFunctions
 import snowflake.snowpark.functions
 from snowflake.snowpark.functions import udf, when, sproc
@@ -676,6 +676,9 @@ def decode_expr(self, expr: proto.Expr) -> Any:
                     for kv in expr.seq_map_val.kvs
                 }
 
+            case "sp_datatype_val":
+                return self.decode_data_type_expr(expr.sp_datatype_val.datatype)
+
             case "tuple_val":
                 # vs can be a list of Expr, a single Expr, or ().
                 if hasattr(expr.tuple_val, "vs"):
@@ -803,7 +806,13 @@ def decode_expr(self, expr: proto.Expr) -> Any:
                 return col.is_null()
 
             case "sp_column_sql_expr":
-                return expr.sp_column_sql_expr.sql
+                sql_expr = expr.sp_column_sql_expr.sql
+                # Need to explicitly specify col("*") because of the way sql_expr AST is encoded.
+                return (
+                    snowflake.snowpark.functions.col(sql_expr)
+                    if sql_expr == "*"
+                    else sql_expr
+                )
 
             case "sp_column_string_like":
                 col = self.decode_expr(expr.sp_column_string_like.col)