Better error handling when parsing multiple sql statements

moor_generator/lib/src/analyzer/session.dart

@@ -124,7 +124,14 @@ class DartTask extends FileTask<ParsedDartFile> {
   Future<List<SpecifiedTable>> resolveIncludes(Iterable<String> paths) {
     return Stream.fromFutures(paths.map(
             (path) => session.startMoorTask(backendTask, uri: Uri.parse(path))))
-        .asyncMap((task) => task.compute())
+        .asyncMap((task) async {
+          final result = await task.compute();
+
+          // add errors from nested task to this task as well.
+          task.errors.errors.forEach(reportError);
+
+          return result;
+        })
         .expand((file) => file.declaredTables)
         .toList();
   }

sqlparser/lib/src/reader/parser/parser.dart

@@ -151,9 +151,6 @@ abstract class ParserBase {
   WindowDefinition _windowDefinition();
 }
 
-// todo better error handling and synchronisation, like it's done here:
-// https://craftinginterpreters.com/parsing-expressions.html#synchronizing-a-recursive-descent-parser
-
 class Parser extends ParserBase
     with ExpressionParser, SchemaParser, CrudParser {
   Parser(List<Token> tokens, {bool useMoor = false}) : super(tokens, useMoor);
@@ -180,8 +177,19 @@ class Parser extends ParserBase
   List<Statement> statements() {
     final stmts = <Statement>[];
     while (!_isAtEnd) {
+      try {
         stmts.add(statement(expectEnd: false));
+      } on ParsingError catch (_) {
+        // the error is added to the list errors, so ignore. We skip to the next
+        // semicolon to parse the next statement.
+        _synchronize();
+      }
     }
     return stmts;
   }
+
+  void _synchronize() {
+    // fast-forward to the token after th next semicolon
+    while (!_isAtEnd && _advance().type != TokenType.semicolon) {}
+  }
 }

sqlparser/test/parser/multiple_statements.dart

@@ -0,0 +1,48 @@
+import 'package:sqlparser/sqlparser.dart';
+import 'package:sqlparser/src/reader/parser/parser.dart';
+import 'package:sqlparser/src/reader/tokenizer/scanner.dart';
+import 'package:sqlparser/src/utils/ast_equality.dart';
+import 'package:test/test.dart';
+
+void main() {
+  test('can parse multiple statements', () {
+    final sql = 'UPDATE tbl SET a = b; SELECT * FROM tbl;';
+    final tokens = Scanner(sql).scanTokens();
+    final statements = Parser(tokens).statements();
+
+    enforceEqual(
+      statements[0],
+      UpdateStatement(
+        table: TableReference('tbl', null),
+        set: [
+          SetComponent(
+            column: Reference(columnName: 'a'),
+            expression: Reference(columnName: 'b'),
+          ),
+        ],
+      ),
+    );
+    enforceEqual(
+      statements[1],
+      SelectStatement(
+        columns: [StarResultColumn(null)],
+        from: [TableReference('tbl', null)],
+      ),
+    );
+  });
+
+  test('recovers from invalid statements', () {
+    final sql = 'UPDATE tbl SET a = * d; SELECT * FROM tbl;';
+    final tokens = Scanner(sql).scanTokens();
+    final statements = Parser(tokens).statements();
+
+    expect(statements, hasLength(1));
+    enforceEqual(
+      statements[0],
+      SelectStatement(
+        columns: [StarResultColumn(null)],
+        from: [TableReference('tbl', null)],
+      ),
+    );
+  });
+}