Apply value transform immediately on construction

src/main/java/org/mybatis/dynamic/sql/AbstractListValueCondition.java

@@ -15,11 +15,11 @@
  */
 package org.mybatis.dynamic.sql;
 
-import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Objects;
 import java.util.function.Function;
 import java.util.function.UnaryOperator;
+import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
 public abstract class AbstractListValueCondition<T> implements VisitableCondition<T> {
@@ -32,12 +32,13 @@ protected AbstractListValueCondition(Collection<T> values) {
     }
 
     protected AbstractListValueCondition(Collection<T> values, UnaryOperator<Stream<T>> valueStreamTransformer) {
-        this.values = new ArrayList<>(Objects.requireNonNull(values));
         this.valueStreamTransformer = Objects.requireNonNull(valueStreamTransformer);
+        this.values = valueStreamTransformer.apply(Objects.requireNonNull(values).stream())
+            .collect(Collectors.toList());
     }
 
     public final <R> Stream<R> mapValues(Function<T, R> mapper) {
-        return valueStreamTransformer.apply(values.stream()).map(mapper);
+        return values.stream().map(mapper);
     }
 
     @Override

src/main/java/org/mybatis/dynamic/sql/where/condition/IsIn.java

@@ -1,5 +1,5 @@
 /**
- *    Copyright 2016-2019 the original author or authors.
+ *    Copyright 2016-2020 the original author or authors.
  *
  *    Licensed under the Apache License, Version 2.0 (the "License");
  *    you may not use this file except in compliance with the License.
@@ -51,7 +51,9 @@ public String renderCondition(String columnName, Stream<String> placeholders) {
      * @return new condition with the specified transformer
      */
     public IsIn<T> then(UnaryOperator<Stream<T>> valueStreamTransformer) {
-        return new IsIn<>(values, valueStreamTransformer);
+        IsIn<T> answer = new IsIn<>(values, valueStreamTransformer);
+        answer.renderWhenEmpty = renderWhenEmpty;
+        return answer;
     }
 
     public static <T> IsIn<T> of(Collection<T> values) {

src/main/java/org/mybatis/dynamic/sql/where/condition/IsInCaseInsensitive.java

@@ -1,5 +1,5 @@
 /**
- *    Copyright 2016-2019 the original author or authors.
+ *    Copyright 2016-2020 the original author or authors.
  *
  *    Licensed under the Apache License, Version 2.0 (the "License");
  *    you may not use this file except in compliance with the License.
@@ -50,7 +50,9 @@ public String renderCondition(String columnName, Stream<String> placeholders) {
      * @return new condition with the specified transformer
      */
     public IsInCaseInsensitive then(UnaryOperator<Stream<String>> valueStreamTransformer) {
-        return new IsInCaseInsensitive(values, valueStreamTransformer);
+        IsInCaseInsensitive answer = new IsInCaseInsensitive(values, valueStreamTransformer);
+        answer.renderWhenEmpty = renderWhenEmpty;
+        return answer;
     }
 
     public static IsInCaseInsensitive of(Collection<String> values) {

src/main/java/org/mybatis/dynamic/sql/where/condition/IsNotIn.java

@@ -1,5 +1,5 @@
 /**
- *    Copyright 2016-2019 the original author or authors.
+ *    Copyright 2016-2020 the original author or authors.
  *
  *    Licensed under the Apache License, Version 2.0 (the "License");
  *    you may not use this file except in compliance with the License.
@@ -52,7 +52,9 @@ public String renderCondition(String columnName, Stream<String> placeholders) {
      * @return new condition with the specified transformer
      */
     public IsNotIn<T> then(UnaryOperator<Stream<T>> valueStreamTransformer) {
-        return new IsNotIn<>(values, valueStreamTransformer);
+        IsNotIn<T> answer = new IsNotIn<>(values, valueStreamTransformer);
+        answer.renderWhenEmpty = renderWhenEmpty;
+        return answer;
     }
 
     public static <T> IsNotIn<T> of(Collection<T> values) {

src/main/java/org/mybatis/dynamic/sql/where/condition/IsNotInCaseInsensitive.java

@@ -1,5 +1,5 @@
 /**
- *    Copyright 2016-2019 the original author or authors.
+ *    Copyright 2016-2020 the original author or authors.
  *
  *    Licensed under the Apache License, Version 2.0 (the "License");
  *    you may not use this file except in compliance with the License.
@@ -51,7 +51,9 @@ public String renderCondition(String columnName, Stream<String> placeholders) {
      * @return new condition with the specified transformer
      */
     public IsNotInCaseInsensitive then(UnaryOperator<Stream<String>> valueStreamTransformer) {
-        return new IsNotInCaseInsensitive(values, valueStreamTransformer);
+        IsNotInCaseInsensitive answer = new IsNotInCaseInsensitive(values, valueStreamTransformer);
+        answer.renderWhenEmpty = renderWhenEmpty;
+        return answer;
     }
 
     public static IsNotInCaseInsensitive of(Collection<String> values) {

src/test/java/examples/animal/data/AnimalDataTest.java

@@ -27,10 +27,12 @@
 import java.sql.Connection;
 import java.sql.DriverManager;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
 import java.util.Map;
+import java.util.Objects;
 
 import org.apache.ibatis.datasource.unpooled.UnpooledDataSource;
 import org.apache.ibatis.exceptions.PersistenceException;
@@ -57,6 +59,7 @@
 import org.mybatis.dynamic.sql.update.render.UpdateStatementProvider;
 import org.mybatis.dynamic.sql.util.mybatis3.MyBatis3Utils;
 import org.mybatis.dynamic.sql.where.condition.IsIn;
+import org.mybatis.dynamic.sql.where.condition.IsNotIn;
 import org.mybatis.dynamic.sql.where.render.WhereClauseProvider;
 
 class AnimalDataTest {
@@ -569,6 +572,47 @@ void testInCondition() {
         }
     }
 
+    @Test
+    void testInConditionWithEventuallyEmptyList() {
+        try (SqlSession sqlSession = sqlSessionFactory.openSession()) {
+            AnimalDataMapper mapper = sqlSession.getMapper(AnimalDataMapper.class);
+
+            SelectStatementProvider selectStatement = select(id, animalName, bodyWeight, brainWeight)
+                    .from(animalData)
+                    .where(id, isIn(null, 22, null).then(s -> s.filter(Objects::nonNull).filter(i -> i != 22)))
+                    .build()
+                    .render(RenderingStrategies.MYBATIS3);
+
+            assertThat(selectStatement.getSelectStatement())
+                    .isEqualTo("select id, animal_name, body_weight, brain_weight from AnimalData");
+            List<AnimalData> animals = mapper.selectMany(selectStatement);
+            assertThat(animals).hasSize(65);
+        }
+    }
+
+    @Test
+    void testInConditionWithEventuallyEmptyListForceRendering() {
+        try (SqlSession sqlSession = sqlSessionFactory.openSession()) {
+            AnimalDataMapper mapper = sqlSession.getMapper(AnimalDataMapper.class);
+
+            List<Integer> inValues = new ArrayList<>();
+            inValues.add(null);
+            inValues.add(22);
+            inValues.add(null);
+
+            SelectStatementProvider selectStatement = select(id, animalName, bodyWeight, brainWeight)
+                    .from(animalData)
+                    .where(id, IsInRequired.isIn(inValues).then(s -> s.filter(Objects::nonNull).filter(i -> i != 22)))
+                    .build()
+                    .render(RenderingStrategies.MYBATIS3);
+
+            assertThat(selectStatement.getSelectStatement())
+                    .isEqualTo("select id, animal_name, body_weight, brain_weight from AnimalData where id in ()");
+
+            assertThatExceptionOfType(PersistenceException.class).isThrownBy(() -> mapper.selectMany(selectStatement));
+        }
+    }
+
     @Test
     void testInConditionWithEmptyList() {
         try (SqlSession sqlSession = sqlSessionFactory.openSession()) {
@@ -659,6 +703,54 @@ void testNotInCaseSensitiveConditionWithNull() {
         }
     }
 
+    @Test
+    void testNotInConditionWithEventuallyEmptyList() {
+        try (SqlSession sqlSession = sqlSessionFactory.openSession()) {
+            AnimalDataMapper mapper = sqlSession.getMapper(AnimalDataMapper.class);
+
+            SelectStatementProvider selectStatement = select(id, animalName, bodyWeight, brainWeight)
+                    .from(animalData)
+                    .where(id, isNotIn(null, 22, null).then(s -> s.filter(Objects::nonNull).filter(i -> i != 22)))
+                    .build()
+                    .render(RenderingStrategies.MYBATIS3);
+
+            assertThat(selectStatement.getSelectStatement())
+                    .isEqualTo("select id, animal_name, body_weight, brain_weight from AnimalData");
+            List<AnimalData> animals = mapper.selectMany(selectStatement);
+            assertThat(animals).hasSize(65);
+        }
+    }
+
+    @Test
+    void testNotInConditionWithEventuallyEmptyListForceRendering() {
+        try (SqlSession sqlSession = sqlSessionFactory.openSession()) {
+            AnimalDataMapper mapper = sqlSession.getMapper(AnimalDataMapper.class);
+
+            SelectStatementProvider selectStatement = select(id, animalName, bodyWeight, brainWeight)
+                    .from(animalData)
+                    .where(id, IsNotInRequired.isNotIn(null, 22, null)
+                            .then(s -> s.filter(Objects::nonNull).filter(i -> i != 22)))
+                    .build()
+                    .render(RenderingStrategies.MYBATIS3);
+
+            assertThat(selectStatement.getSelectStatement())
+                    .isEqualTo("select id, animal_name, body_weight, brain_weight from AnimalData where id not in ()");
+
+            assertThatExceptionOfType(PersistenceException.class).isThrownBy(() -> mapper.selectMany(selectStatement));
+        }
+    }
+
+    public static class IsNotInRequired<T> extends IsNotIn<T> {
+        protected IsNotInRequired(Collection<T> values) {
+            super(values);
+            forceRenderingWhenEmpty();
+        }
+
+        @SafeVarargs
+        public static <T> IsNotInRequired<T> isNotIn(T...values) {
+            return new IsNotInRequired<>(Arrays.asList(values));
+        }
+    }
     @Test
     void testLikeCondition() {
         try (SqlSession sqlSession = sqlSessionFactory.openSession()) {