Add warnings for `customConstraint` misuse

drift_dev/lib/src/analyzer/dart/column_parser.dart

@@ -29,6 +29,14 @@ const String _methodDefault = 'withDefault';
 const String _methodClientDefault = 'clientDefault';
 const String _methodMap = 'map';
 const String _methodGenerated = 'generatedAs';
+const Set<String> _addsSqlConstraint = {
+  _methodNamed,
+  _methodReferences,
+  _methodAutoIncrement,
+  _methodUnique,
+  _methodDefault,
+  _methodGenerated
+};
 
 const String _errorMessage = 'This getter does not create a valid column that '
     'can be parsed by moor. Please refer to the readme from moor to see how '
@@ -74,6 +82,7 @@ class ColumnParser {
     DriftDartType? typeConverterRuntime;
     ColumnGeneratedAs? generatedAs;
     var nullable = false;
+    var hasDefaultConstraints = false;
 
     final foundFeatures = <ColumnFeature>[];
 
@@ -85,6 +94,10 @@ class ColumnParser {
         break;
       }
 
+      if (_addsSqlConstraint.contains(methodName)) {
+        hasDefaultConstraints = true;
+      }
+
       switch (methodName) {
         case _methodNamed:
           if (foundExplicitName != null) {
@@ -223,6 +236,19 @@ class ColumnParser {
           foundFeatures.add(const UniqueKey());
           break;
         case _methodCustomConstraint:
+          if (foundCustomConstraint != null) {
+            base.step.reportError(
+              ErrorInDartCode(
+                severity: Severity.warning,
+                affectedElement: getter.declaredElement,
+                affectedNode: remainingExpr.methodName,
+                message:
+                    "You've already set custom constraints on this column, "
+                    'they will be overriden by this call.',
+              ),
+            );
+          }
+
           foundCustomConstraint = base.readStringLiteral(
               remainingExpr.argumentList.arguments.first, () {
             base.step.reportError(
@@ -370,6 +396,19 @@ class ColumnParser {
       );
     }
 
+    if (hasDefaultConstraints && foundCustomConstraint != null) {
+      base.step.reportError(
+        ErrorInDartCode(
+          severity: Severity.warning,
+          affectedElement: getter.declaredElement,
+          message: 'This column definition is using both drift-defined '
+              'constraints (like references, autoIncrement, ...) and a '
+              'customConstraint(). Only the custom constraint will be added '
+              'to the column in SQL!',
+        ),
+      );
+    }
+
     final docString =
         getter.documentationComment?.tokens.map((t) => t.toString()).join('\n');
     return MoorColumn(

drift_dev/test/analyzer/dart/table_parser_test.dart

@@ -11,6 +11,7 @@ import 'package:drift_dev/writer.dart';
 import 'package:test/test.dart';
 
 import '../../utils/test_backend.dart';
+import '../utils.dart';
 
 void main() {
   late TestBackend backend;
@@ -118,6 +119,14 @@ void main() {
       @DriftDatabase(tables: [Foo, DoesNotExist])
       class Database {}
       ''',
+      AssetId.parse('test_lib|lib/invalid_constraints.dart'): '''
+      import 'package:drift/drift.dart';
+
+      class InvalidConstraints extends Table {
+        IntColumn get a => integer().autoIncrement().customConstraint('foo')();
+        IntColumn get b => integer().customConstraint('a').customConstraint('b')();
+      }
+      ''',
     });
   });
   tearDownAll(() {
@@ -366,4 +375,26 @@ void main() {
       ),
     );
   });
+
+  test('reports errors around suspicous customConstraint uses', () async {
+    final session = MoorSession(backend);
+    final uri = Uri.parse('package:test_lib/invalid_constraints.dart');
+    final backendTask = backend.startTask(uri);
+    final task = session.startTask(backendTask);
+    await task.runTask();
+
+    final file = session.registerFile(uri);
+    file.expectDartError(
+      allOf(
+        contains(
+            'This column definition is using both drift-defined constraints'),
+        contains('and a customConstraint()'),
+      ),
+      'a',
+    );
+    file.expectDartError(
+      contains("You've already set custom constraints on this column"),
+      'customConstraint',
+    );
+  });
 }