feat: named arguments

README.md

@@ -5,11 +5,11 @@
 
 Useful utilities to augment [sqflite](https://pub.dev/packages/sqflite). Designed to be unobtrusive helpers, so you still access sqflite directly (not a wrapper).
 
-## Features
+## Usage
 
-- Functions for working with `bool` values ([sqflite does not support bool](https://github.com/tekartik/sqflite/blob/master/sqflite/doc/supported_types.md#supported-sqlite-types))
+### Bool utilities
 
-## Usage
+Sqflite does not support the `bool` type ([reference](https://github.com/tekartik/sqflite/blob/master/sqflite/doc/supported_types.md#supported-sqlite-types)).
 
 ```dart
 import 'package:sqflite_ext/sqflite_ext.dart';
@@ -25,5 +25,17 @@ intToBool(1);
 
 intToBoolOrNull(null);
 // => null
+```
+
+### Named arguments
+
+```dart
+import 'package:sqflite_ext/sqflite_ext.dart';
 
+final result = parseNamedArgs(
+  'SELECT * FROM demo WHERE id = :id',
+  {'id': 83},
+);
+// result.query => 'SELECT * FROM demo WHERE id = ?'
+// result.arguments => [83]
 ```

example/example.dart

@@ -27,6 +27,13 @@ void main() async {
   // use with json_annotation (see class DemoItem below)
   const item = DemoItem(isAwesome: true);
   await db.insert('demo', item.toJson());
+
+  // query with named args
+  final p = parseNamedArgs(
+    'SELECT * FROM demo WHERE isAwesome = :status',
+    {'status': true},
+  );
+  await db.query(p.query, whereArgs: p.arguments);
 }
 
 @immutable

lib/sqflite_ext.dart

@@ -1,3 +1,4 @@
 library sqflite_ext;
 
 export 'src/boolean_utils.dart';
+export 'src/parse_named_args.dart';

lib/src/parse_named_args.dart

@@ -0,0 +1,25 @@
+/// A parsed raw query + argument values.
+class QueryWithArgs {
+  QueryWithArgs(this.query, this.arguments);
+
+  /// Query with named arguments replace with placeholders (?).
+  String query;
+
+  /// List of query argument values.
+  List<Object?> arguments;
+}
+
+/// Parse a query with named arguments into a raw query + argument values.
+QueryWithArgs parseNamedArgs(String query, Map<String, dynamic> params) {
+  final exp = RegExp(r":([\w]+)");
+  List<Object?> arguments = [];
+  RegExpMatch? match;
+
+  while ((match = exp.firstMatch(query)) != null) {
+    final name = query.substring(match!.start + 1, match.end);
+    query = query.replaceRange(match.start, match.end, '?');
+    arguments.add(params[name]);
+  }
+
+  return QueryWithArgs(query, arguments);
+}

test/src/parse_named_args_test.dart

@@ -0,0 +1,62 @@
+import 'package:flutter_test/flutter_test.dart';
+import 'package:sqflite_ext/src/parse_named_args.dart';
+
+void main() {
+  group('parseNamedArgs', () {
+    test('with no params', () {
+      final result = parseNamedArgs(
+        'SELECT * FROM demo',
+        {},
+      );
+
+      expect(result.query, 'SELECT * FROM demo');
+      expect(result.arguments, []);
+    });
+
+    test('with missing param', () {
+      final result = parseNamedArgs(
+        'SELECT * FROM demo WHERE id = :fail',
+        {},
+      );
+
+      expect(result.query, 'SELECT * FROM demo WHERE id = ?');
+      expect(result.arguments, [null]);
+    });
+
+    test('with a single param', () {
+      final result = parseNamedArgs(
+        'SELECT * FROM demo WHERE id = :id',
+        {'id': 83},
+      );
+
+      expect(result.query, 'SELECT * FROM demo WHERE id = ?');
+      expect(result.arguments, [83]);
+    });
+
+    test('with multiple different params', () {
+      final result = parseNamedArgs(
+        'SELECT * FROM demo WHERE a = :a AND b = :b AND c = :c',
+        {'a': 83, 'b': 'active', 'c': true},
+      );
+
+      expect(
+        result.query,
+        'SELECT * FROM demo WHERE a = ? AND b = ? AND c = ?',
+      );
+      expect(result.arguments, [83, 'active', true]);
+    });
+
+    test('with the same param multiple times', () {
+      final result = parseNamedArgs(
+        'SELECT * FROM demo WHERE a = :a AND b = :b AND c = :b',
+        {'a': 83, 'b': 'active'},
+      );
+
+      expect(
+        result.query,
+        'SELECT * FROM demo WHERE a = ? AND b = ? AND c = ?',
+      );
+      expect(result.arguments, [83, 'active', 'active']);
+    });
+  });
+}