Improve error messages for unsupported update assignments (#131)

Author: vbabanin

src/integrationTest/java/com/mongodb/hibernate/query/mutation/UpdatingIntegrationTests.java

@@ -17,6 +17,7 @@
 package com.mongodb.hibernate.query.mutation;
 
 import com.mongodb.client.MongoCollection;
+import com.mongodb.hibernate.internal.FeatureNotSupportedException;
 import com.mongodb.hibernate.junit.InjectMongoCollection;
 import com.mongodb.hibernate.query.AbstractQueryIntegrationTests;
 import com.mongodb.hibernate.query.Book;
@@ -25,6 +26,7 @@
 import org.bson.BsonDocument;
 import org.hibernate.testing.orm.junit.DomainModel;
 import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Nested;
 import org.junit.jupiter.api.Test;
 
 @DomainModel(annotatedClasses = Book.class)
@@ -228,4 +230,37 @@ void testUpdateWithZeroMutationCount() {
                                 """)),
                 Set.of(Book.COLLECTION_NAME));
     }
+
+    @Nested
+    class Unsupported {
+        @Test
+        void testFunctionExpressionAssignment() {
+            var hql = "update Book b set b.title = upper(b.title) where b.id = 1";
+            assertMutationQueryFailure(
+                    hql,
+                    query -> {},
+                    FeatureNotSupportedException.class,
+                    "Function expression [upper] as update assignment value for field path [title] is not supported");
+        }
+
+        @Test
+        void testPredicateExpressionAssignment() {
+            var hql = "update Book b set b.outOfStock = (b.publishYear > 2000) where b.id = 2";
+            assertMutationQueryFailure(
+                    hql,
+                    query -> {},
+                    FeatureNotSupportedException.class,
+                    "Predicate expression as update assignment value for field path [outOfStock] is not supported");
+        }
+
+        @Test
+        void testPathExpressionAssignment() {
+            var hql = "update Book b set b.publishYear = b.isbn13 where b.id = 3";
+            assertMutationQueryFailure(
+                    hql,
+                    query -> {},
+                    FeatureNotSupportedException.class,
+                    "Path expression as update assignment value for field path [publishYear] is not supported");
+        }
+    }
 }

src/main/java/com/mongodb/hibernate/internal/translate/AbstractMqlTranslator.java

@@ -101,6 +101,7 @@
 import org.hibernate.query.sqm.function.SelfRenderingFunctionSqlAstExpression;
 import org.hibernate.query.sqm.sql.internal.BasicValuedPathInterpretation;
 import org.hibernate.query.sqm.sql.internal.SqmParameterInterpretation;
+import org.hibernate.query.sqm.sql.internal.SqmPathInterpretation;
 import org.hibernate.query.sqm.tree.expression.Conversion;
 import org.hibernate.sql.ast.Clause;
 import org.hibernate.sql.ast.SqlAstNodeRenderingMode;
@@ -130,6 +131,7 @@
 import org.hibernate.sql.ast.tree.expression.Expression;
 import org.hibernate.sql.ast.tree.expression.ExtractUnit;
 import org.hibernate.sql.ast.tree.expression.Format;
+import org.hibernate.sql.ast.tree.expression.FunctionExpression;
 import org.hibernate.sql.ast.tree.expression.JdbcLiteral;
 import org.hibernate.sql.ast.tree.expression.JdbcParameter;
 import org.hibernate.sql.ast.tree.expression.Literal;
@@ -169,6 +171,7 @@
 import org.hibernate.sql.ast.tree.predicate.LikePredicate;
 import org.hibernate.sql.ast.tree.predicate.NegatedPredicate;
 import org.hibernate.sql.ast.tree.predicate.NullnessPredicate;
+import org.hibernate.sql.ast.tree.predicate.Predicate;
 import org.hibernate.sql.ast.tree.predicate.SelfRenderingPredicate;
 import org.hibernate.sql.ast.tree.predicate.ThruthnessPredicate;
 import org.hibernate.sql.ast.tree.select.QueryGroup;
@@ -694,7 +697,8 @@ public void visitUpdateStatement(UpdateStatement updateStatement) {
             var fieldPath = acceptAndYield(fieldReferences.get(0), FIELD_PATH);
             var assignedValue = assignment.getAssignedValue();
             if (!isValueExpression(assignedValue)) {
-                throw new FeatureNotSupportedException();
+                throw new FeatureNotSupportedException(
+                        getUnsupportedUpdateValueAssignmentMessage(fieldPath, assignedValue));
             }
             var fieldValue = acceptAndYield(assignedValue, VALUE);
             fieldUpdates.add(new AstFieldUpdate(fieldPath, fieldValue));
@@ -1205,4 +1209,19 @@ public void appendSql(String fragment) {
             throw new FeatureNotSupportedException();
         }
     }
+
+    private static String getUnsupportedUpdateValueAssignmentMessage(final String fieldPath, Expression assignedValue) {
+        if (assignedValue instanceof FunctionExpression ex) {
+            return "Function expression [%s] as update assignment value for field path [%s] is not supported"
+                    .formatted(ex.getFunctionName(), fieldPath);
+        } else if (assignedValue instanceof Predicate) {
+            return "Predicate expression as update assignment value for field path [%s] is not supported"
+                    .formatted(fieldPath);
+        } else if (assignedValue instanceof SqmPathInterpretation) {
+            return "Path expression as update assignment value for field path [%s] is not supported"
+                    .formatted(fieldPath);
+        } else {
+            return "Update assignment value for field path [%s] is not supported".formatted(fieldPath);
+        }
+    }
 }