Add `isIn` methods based on expressions

drift/CHANGELOG.md

@@ -1,6 +1,8 @@
 ## 2.11.0
 
 - Add support for subqueries in the Dart query builder.
+- Add `isInExp` and `isNotInExp` to construct `IS IN` expressions with arbitrary
+  expressions.
 
 ## 2.10.0
 

drift/lib/src/runtime/query_builder/expressions/expression.dart

@@ -142,13 +142,29 @@ abstract class Expression<D extends Object> implements FunctionParameter {
   /// An expression that is true if `this` resolves to any of the values in
   /// [values].
   Expression<bool> isIn(Iterable<D> values) {
-    return _InExpression(this, values.toList(), false);
+    return isInExp([for (final value in values) Variable<D>(value)]);
   }
 
   /// An expression that is true if `this` does not resolve to any of the values
   /// in [values].
   Expression<bool> isNotIn(Iterable<D> values) {
-    return _InExpression(this, values.toList(), true);
+    return isNotInExp([for (final value in values) Variable<D>(value)]);
+  }
+
+  /// An expression that evaluates to `true` if this expression resolves to a
+  /// value that one of the [expressions] resolve to as well.
+  ///
+  /// For an "is in" comparison with values, use [isIn].
+  Expression<bool> isInExp(List<Expression<D>> expressions) {
+    return _InExpression(this, expressions, false);
+  }
+
+  /// An expression that evaluates to `true` if this expression does not resolve
+  /// to any value that the [expressions] resolve to.
+  ///
+  /// For an "is not in" comparison with values, use [isNotIn].
+  Expression<bool> isNotInExp(List<Expression<D>> expressions) {
+    return _InExpression(this, expressions, true);
   }
 
   /// An expression checking whether `this` is included in any row of the

drift/lib/src/runtime/query_builder/expressions/in.dart

@@ -1,6 +1,6 @@
 part of '../query_builder.dart';
 
-abstract class _BaseInExpression extends Expression<bool> {
+sealed class _BaseInExpression extends Expression<bool> {
   final Expression _expression;
   final bool _not;
 
@@ -25,8 +25,8 @@ abstract class _BaseInExpression extends Expression<bool> {
   void _writeValues(GenerationContext context);
 }
 
-class _InExpression<T extends Object> extends _BaseInExpression {
+final class _InExpression<T extends Object> extends _BaseInExpression {
-  final List<T> _values;
+  final List<Expression<T>> _values;
 
   _InExpression(Expression expression, this._values, bool not)
       : super(expression, not);
@@ -35,15 +35,13 @@ class _InExpression<T extends Object> extends _BaseInExpression {
   void _writeValues(GenerationContext context) {
     var first = true;
     for (final value in _values) {
-      final variable = Variable<T>(value);
-
       if (first) {
         first = false;
       } else {
         context.buffer.write(', ');
       }
 
-      variable.writeInto(context);
+      value.writeInto(context);
     }
   }
 
@@ -59,7 +57,7 @@ class _InExpression<T extends Object> extends _BaseInExpression {
   }
 }
 
-class _InSelectExpression extends _BaseInExpression {
+final class _InSelectExpression extends _BaseInExpression {
   final BaseSelectStatement _select;
 
   _InSelectExpression(this._select, Expression expression, bool not)

drift/test/database/expressions/in_expression_test.dart

@@ -23,6 +23,26 @@ void main() {
     });
   });
 
+  group('expressions', () {
+    test('in', () {
+      final isInExpression = innerExpression.isInExp([
+        CustomExpression('a'),
+        CustomExpression('b'),
+      ]);
+
+      expect(isInExpression, generates('name IN (a, b)'));
+    });
+
+    test('not in', () {
+      final isNotInExpression = innerExpression.isNotInExp([
+        CustomExpression('a'),
+        CustomExpression('b'),
+      ]);
+
+      expect(isNotInExpression, generates('name NOT IN (a, b)'));
+    });
+  });
+
   group('subquery', () {
     test('in expressions are generated', () {
       final isInExpression = innerExpression