Fix clippy and tests

Author: alamb

parquet-variant-compute/src/shred_variant.rs

@@ -1291,8 +1291,8 @@ mod tests {
         let input = builder.build();
 
         let target_schema = ShreddedSchemaBuilder::default()
-            .with_path("id", &DataType::FixedSizeBinary(16))
-            .with_path("session_id", &DataType::FixedSizeBinary(16))
+            .with_path("id", DataType::FixedSizeBinary(16))
+            .with_path("session_id", DataType::FixedSizeBinary(16))
             .build();
 
         let result = shred_variant(&input, &target_schema).unwrap();
@@ -1666,6 +1666,16 @@ mod tests {
         );
     }
 
+    #[test]
+    fn test_variant_schema_builder_root_path() {
+        let path = VariantPath::new(vec![]);
+        let shredding_type = ShreddedSchemaBuilder::default()
+            .with_path(path, &DataType::Int64)
+            .build();
+
+        assert_eq!(shredding_type, DataType::Int64);
+    }
+
     #[test]
     fn test_variant_schema_builder_empty_path() {
         let shredding_type = ShreddedSchemaBuilder::default()

parquet-variant/src/path.rs

@@ -103,7 +103,11 @@ impl<'a> From<Vec<VariantPathElement<'a>>> for VariantPath<'a> {
 /// Create from &str with support for dot notation
 impl<'a> From<&'a str> for VariantPath<'a> {
     fn from(path: &'a str) -> Self {
-        VariantPath::new(path.split('.').map(Into::into).collect())
+        if path.is_empty() {
+            VariantPath::new(vec![])
+        } else {
+            VariantPath::new(path.split('.').map(Into::into).collect())
+        }
     }
 }
 
@@ -198,6 +202,12 @@ mod tests {
         assert!(path.is_empty());
     }
 
+    #[test]
+    fn test_variant_path_empty_str() {
+        let path = VariantPath::from("");
+        assert!(path.is_empty());
+    }
+
     #[test]
     fn test_variant_path_non_empty() {
         let p = VariantPathElement::from("a");