test: updates scaffolding for UdfSqlToSubstraitTest

Author: vbarua

isthmus/src/main/java/io/substrait/isthmus/ConverterProvider.java

@@ -21,7 +21,7 @@ public class ConverterProvider {
 
   protected final RelDataTypeFactory typeFactory;
 
-  private final ScalarFunctionConverter scalarFunctionConverter;
+  protected ScalarFunctionConverter scalarFunctionConverter;
   private final AggregateFunctionConverter aggregateFunctionConverter;
   private final WindowFunctionConverter windowFunctionConverter;
 

isthmus/src/main/java/io/substrait/isthmus/DynamicConverterProvider.java

@@ -16,8 +16,6 @@ public class DynamicConverterProvider extends ConverterProvider {
 
   private final SimpleExtension.ExtensionCollection extensions;
 
-  private final ScalarFunctionConverter scalarFunctionConverter;
-
   public DynamicConverterProvider(
       RelDataTypeFactory typeFactory, SimpleExtension.ExtensionCollection extensions) {
     super(typeFactory, extensions);

isthmus/src/main/java/io/substrait/isthmus/SubstraitRelVisitor.java

@@ -613,6 +613,35 @@ public static Plan.Root convert(RelRoot relRoot, SimpleExtension.ExtensionCollec
     return convert(relRoot, extensions, FEATURES_DEFAULT);
   }
 
+  /**
+   * Converts a Calcite {@link RelRoot} to a Substrait {@link Plan.Root} using a custom visitor.
+   *
+   * <p>This is the main conversion entry point for a complete plan. It applies the provided {@link
+   * SubstraitRelVisitor} to the final projected {@link RelNode} from the {@code relRoot}, and wraps
+   * the resulting {@link Rel} in a {@link Plan.Root}.
+   *
+   * <p>This method also correctly extracts the final output field names, paying special attention
+   * to nested types (structs, maps) via the visitor's type converter, rather than using the names
+   * from {@code relRoot.validatedRowType} directly.
+   *
+   * @param relRoot The Calcite RelRoot to convert. This is expected to be a complete, optimized
+   *     plan.
+   * @param visitor {@link SubstraitRelVisitor} or its subclass. This allows for custom visitor
+   *     behavior.
+   * @return The resulting Substrait Plan.Root, containing the converted relational tree and the
+   *     output names.
+   */
+  public static Plan.Root convert(RelRoot relRoot, ConverterProvider converterProvider) {
+    SubstraitRelVisitor visitor = new SubstraitRelVisitor(converterProvider);
+    visitor.popFieldAccessDepthMap(relRoot.rel);
+    Rel rel = visitor.apply(relRoot.project());
+
+    // Avoid using the names from relRoot.validatedRowType because if there are
+    // nested types (i.e ROW, MAP, etc) the typeConverter will pad names correctly
+    List<String> names = visitor.typeConverter.toNamedStruct(relRoot.validatedRowType).names();
+    return Plan.Root.builder().input(rel).names(names).build();
+  }
+
   /**
    * Converts a Calcite {@link RelRoot} to a Substrait {@link Plan.Root} using a custom visitor.
    *

isthmus/src/test/java/io/substrait/isthmus/PlanTestBase.java

@@ -50,6 +50,8 @@ public class PlanTestBase {
 
   protected static final CalciteCatalogReader TPCH_CATALOG;
 
+  protected ConverterProvider converterProvider;
+
   static {
     try {
       String tpchCreateStatements = asString("tpch/schema.sql");
@@ -69,8 +71,14 @@ protected PlanTestBase() {
   }
 
   protected PlanTestBase(SimpleExtension.ExtensionCollection extensions) {
+    this(extensions, new ConverterProvider(extensions));
+  }
+
+  protected PlanTestBase(
+      SimpleExtension.ExtensionCollection extensions, ConverterProvider converterProvider) {
     this.extensions = extensions;
     this.substraitBuilder = new SubstraitBuilder(extensions);
+    this.converterProvider = converterProvider;
   }
 
   public static String asString(String resource) throws IOException {
@@ -134,7 +142,8 @@ protected RelRoot assertSqlSubstraitRelRoundTrip(
     // Return list of sql -> Substrait rel -> Calcite rel.
 
     SqlToSubstrait s2s = new SqlToSubstrait();
-    SubstraitToCalcite substraitToCalcite = new SubstraitToCalcite(extensions, typeFactory);
+    SubstraitToCalcite substraitToCalcite =
+        new SubstraitToCalcite(converterProvider, catalogReader);
 
     // 1. SQL -> Substrait Plan
     Plan plan1 = s2s.convert(query, catalogReader);
@@ -146,7 +155,7 @@ protected RelRoot assertSqlSubstraitRelRoundTrip(
     RelRoot relRoot2 = substraitToCalcite.convert(pojo1);
 
     // 4. Calcite RelNode -> Substrait Rel
-    Plan.Root pojo2 = SubstraitRelVisitor.convert(relRoot2, extensions);
+    Plan.Root pojo2 = SubstraitRelVisitor.convert(relRoot2, converterProvider);
 
     assertEquals(pojo1, pojo2);
     return relRoot2;
@@ -181,11 +190,11 @@ protected RelRoot assertSqlSubstraitRelRoundTripLoosePojoComparison(
         featureBoard != null ? featureBoard : ImmutableFeatureBoard.builder().build();
 
     SubstraitToCalcite substraitToCalcite =
-        new SubstraitToCalcite(extensions, typeFactory, TypeConverter.DEFAULT, null, features);
-    SqlToSubstrait s = new SqlToSubstrait(extensions, features);
+        new SubstraitToCalcite(converterProvider, catalogReader);
+    SqlToSubstrait sqlToSubstrait = new SqlToSubstrait(extensions, converterProvider, featureBoard);
 
     // 1. SQL -> Substrait Plan
-    Plan plan1 = s.convert(query, catalogReader);
+    Plan plan1 = sqlToSubstrait.convert(query, catalogReader);
 
     // 2. Substrait Plan -> Substrait Root (POJO 1)
     Plan.Root pojo1 = plan1.getRoots().get(0);
@@ -194,7 +203,7 @@ protected RelRoot assertSqlSubstraitRelRoundTripLoosePojoComparison(
     RelRoot relRoot2 = substraitToCalcite.convert(pojo1);
 
     // 4. Calcite RelNode -> Substrait Root (POJO 2)
-    Plan.Root pojo2 = SubstraitRelVisitor.convert(relRoot2, extensions, features);
+    Plan.Root pojo2 = SubstraitRelVisitor.convert(relRoot2, converterProvider);
 
     // Note: pojo1 and pojo2 may differ due to different optimization strategies applied by:
     // - SqlNode->RelRoot conversion during SQL->Substrait conversion
@@ -205,7 +214,7 @@ protected RelRoot assertSqlSubstraitRelRoundTripLoosePojoComparison(
     RelRoot relRoot3 = substraitToCalcite.convert(pojo2);
 
     // 6. Calcite RelNode -> Substrait Root (POJO 3)
-    Plan.Root pojo3 = SubstraitRelVisitor.convert(relRoot3, extensions, features);
+    Plan.Root pojo3 = SubstraitRelVisitor.convert(relRoot3, converterProvider);
 
     // Verify that subsequent round trips are stable (pojo2 and pojo3 should be identical)
     assertEquals(pojo2, pojo3);

isthmus/src/test/java/io/substrait/isthmus/UdfSqlSubstraitTest.java

@@ -13,6 +13,7 @@ class UdfSqlSubstraitTest extends PlanTestBase {
 
   UdfSqlSubstraitTest() {
     super(loadExtensions(List.of(CUSTOM_FUNCTION_PATH)));
+    this.converterProvider = new DynamicConverterProvider(typeFactory, extensions);
   }
 
   @Test