Handle equality and hashes for blobs

drift/lib/drift.dart

@@ -1,5 +1,7 @@
 library drift;
 
+import 'package:collection/collection.dart';
+
 // needed for the generated code that generates data classes with an Uint8List
 // field.
 export 'dart:typed_data' show Uint8List;
@@ -17,3 +19,7 @@ export 'src/runtime/query_builder/query_builder.dart';
 export 'src/runtime/types/converters.dart';
 export 'src/runtime/types/mapping.dart';
 export 'src/utils/lazy_database.dart';
+
+/// A [ListEquality] instance used by generated drift code for the `==` and
+/// [Object.hashCode] implementation of generated classes if they contain lists.
+const ListEquality $driftBlobEquality = ListEquality();

drift/test/generated/todos.g.dart

@@ -650,8 +650,8 @@ class User extends DataClass implements Insertable<User> {
   }
 
   @override
-  int get hashCode =>
-      Object.hash(id, name, isAwesome, profilePicture, creationTime);
+  int get hashCode => Object.hash(id, name, isAwesome,
+      $driftBlobEquality.hash(profilePicture), creationTime);
   @override
   bool operator ==(Object other) =>
       identical(this, other) ||
@@ -659,7 +659,8 @@ class User extends DataClass implements Insertable<User> {
           other.id == this.id &&
           other.name == this.name &&
           other.isAwesome == this.isAwesome &&
-          other.profilePicture == this.profilePicture &&
+          $driftBlobEquality.equals(
+              other.profilePicture, this.profilePicture) &&
           other.creationTime == this.creationTime);
 }
 

drift_dev/lib/src/model/types.dart

@@ -63,6 +63,9 @@ class DriftDartType {
 }
 
 extension OperationOnTypes on HasType {
+  bool get isUint8ListInDart =>
+      type == DriftSqlType.blob && typeConverter == null;
+
   /// Whether this type is nullable in Dart
   bool get nullableInDart {
     if (isArray) return false; // Is a List<Something> in Dart, not nullable

drift_dev/lib/src/writer/queries/result_set_writer.dart

@@ -12,7 +12,7 @@ class ResultSetWriter {
 
   void write() {
     final className = query.resultClassName;
-    final fieldNames = <String>[];
+    final fields = <EqualityField>[];
     final nonNullableFields = <String>{};
     final into = scope.leaf();
 
@@ -34,7 +34,7 @@ class ResultSetWriter {
 
       into.write('$modifier $runtimeType $name\n;');
 
-      fieldNames.add(name);
+      fields.add(EqualityField(name, isList: column.isUint8ListInDart));
       if (!column.nullable) nonNullableFields.add(name);
     }
 
@@ -49,7 +49,7 @@ class ResultSetWriter {
 
         into.write('$modifier $typeName $fieldName;\n');
 
-        fieldNames.add(fieldName);
+        fields.add(EqualityField(fieldName));
         if (!nested.isNullable) nonNullableFields.add(fieldName);
       } else if (nested is NestedResultQuery) {
         final fieldName = nested.filedName();
@@ -61,7 +61,7 @@ class ResultSetWriter {
 
         into.write('$modifier List<$typeName> $fieldName;\n');
 
-        fieldNames.add(fieldName);
+        fields.add(EqualityField(fieldName));
         nonNullableFields.add(fieldName);
       }
     }
@@ -73,11 +73,11 @@ class ResultSetWriter {
       into.write('$className({');
     }
 
-    for (final column in fieldNames) {
-      if (nonNullableFields.contains(column)) {
+    for (final column in fields) {
+      if (nonNullableFields.contains(column.lexeme)) {
         into.write('required ');
       }
-      into.write('this.$column,');
+      into.write('this.${column.lexeme},');
     }
 
     if (scope.options.rawResultSetData) {
@@ -89,11 +89,11 @@ class ResultSetWriter {
     // if requested, override hashCode and equals
     if (scope.writer.options.overrideHashAndEqualsInResultSets) {
       into.write('@override int get hashCode => ');
-      const HashCodeWriter().writeHashCode(fieldNames, into);
+      writeHashCode(fields, into);
       into.write(';\n');
 
-      overrideEquals(fieldNames, className, into);
-      overrideToString(className, fieldNames, into);
+      overrideEquals(fields, className, into);
+      overrideToString(className, fields.map((f) => f.lexeme).toList(), into);
     }
 
     into.write('}\n');

drift_dev/lib/src/writer/tables/data_class_writer.dart

@@ -87,7 +87,11 @@ class DataClassWriter {
     _writeHashCode();
 
     overrideEquals(
-        columns.map((c) => c.dartGetterName), table.dartTypeCode(), _buffer);
+      columns.map(
+          (c) => EqualityField(c.dartGetterName, isList: c.isUint8ListInDart)),
+      table.dartTypeCode(),
+      _buffer,
+    );
 
     // finish class declaration
     _buffer.write('}');
@@ -312,8 +316,11 @@ class DataClassWriter {
   void _writeHashCode() {
     _buffer.write('@override\n int get hashCode => ');
 
-    final fields = columns.map((c) => c.dartGetterName).toList();
-    const HashCodeWriter().writeHashCode(fields, _buffer);
+    final fields = columns
+        .map(
+            (c) => EqualityField(c.dartGetterName, isList: c.isUint8ListInDart))
+        .toList();
+    writeHashCode(fields, _buffer);
     _buffer.write(';');
   }
 }

drift_dev/lib/src/writer/utils/hash_and_equals.dart

@@ -0,0 +1,72 @@
+const int _maxArgsToObjectHash = 20;
+
+class EqualityField {
+  /// The Dart expression evaluating the field to include in the hash / equals
+  /// check.
+  final String lexeme;
+
+  /// Whether the field is a list that can't be compared with `==` directly.
+  final bool isList;
+
+  EqualityField(this.lexeme, {this.isList = false});
+}
+
+/// Writes an expression to calculate a hash code of an object that consists
+/// of the [fields].
+void writeHashCode(List<EqualityField> fields, StringBuffer into) {
+  if (fields.isEmpty) {
+    into.write('identityHashCode(this)');
+  } else if (fields.length == 1) {
+    final field = fields[0];
+
+    if (field.isList) {
+      into.write('\$driftBlobEquality.hash(${field.lexeme})');
+    } else {
+      into.write('${field.lexeme}.hashCode');
+    }
+  } else {
+    final needsHashAll = fields.length > _maxArgsToObjectHash;
+
+    into.write(needsHashAll ? 'Object.hashAll([' : 'Object.hash(');
+    var first = true;
+    for (final field in fields) {
+      if (!first) into.write(', ');
+
+      if (field.isList) {
+        into.write('\$driftBlobEquality.hash(${field.lexeme})');
+      } else {
+        into.write(field.lexeme);
+      }
+
+      first = false;
+    }
+
+    into.write(needsHashAll ? '])' : ')');
+  }
+}
+
+/// Writes a operator == override for a class consisting of the [fields] into
+/// the buffer provided by [into].
+void overrideEquals(
+    Iterable<EqualityField> fields, String className, StringBuffer into) {
+  into
+    ..writeln('@override')
+    ..write('bool operator ==(Object other) => ')
+    ..write('identical(this, other) || (other is $className');
+
+  if (fields.isNotEmpty) {
+    into
+      ..write(' && ')
+      ..write(fields.map((field) {
+        final lexeme = field.lexeme;
+
+        if (field.isList) {
+          return '\$driftBlobEquality.equals(other.$lexeme, this.$lexeme)';
+        } else {
+          return 'other.$lexeme == this.$lexeme';
+        }
+      }).join(' && '));
+  }
+
+  into.writeln(');');
+}

drift_dev/lib/src/writer/utils/hash_code.dart

@@ -1,28 +0,0 @@
-class HashCodeWriter {
-  static const int _maxArgsToObjectHash = 20;
-
-  const HashCodeWriter();
-
-  /// Writes an expression to calculate a hash code of an object that consists
-  /// of the [fields].
-  void writeHashCode(List<String> fields, StringBuffer into) {
-    if (fields.isEmpty) {
-      into.write('identityHashCode(this)');
-    } else if (fields.length == 1) {
-      into.write('${fields[0]}.hashCode');
-    } else {
-      final needsHashAll = fields.length > _maxArgsToObjectHash;
-
-      into.write(needsHashAll ? 'Object.hashAll([' : 'Object.hash(');
-      var first = true;
-      for (final field in fields) {
-        if (!first) into.write(', ');
-
-        into.write(field);
-        first = false;
-      }
-
-      into.write(needsHashAll ? '])' : ')');
-    }
-  }
-}

drift_dev/lib/src/writer/utils/override_equals.dart

@@ -1,18 +0,0 @@
-/// Writes a operator == override for a class consisting of the [fields] into
-/// the buffer provided by [into].
-void overrideEquals(
-    Iterable<String> fields, String className, StringBuffer into) {
-  into
-    ..write('@override\nbool operator ==(Object other) => ')
-    ..write('identical(this, other) || (other is $className');
-
-  if (fields.isNotEmpty) {
-    into
-      ..write(' && ')
-      ..write(fields.map((field) {
-        return 'other.$field == this.$field';
-      }).join(' && '));
-  }
-
-  into.write(');\n');
-}

drift_dev/lib/writer.dart

@@ -10,7 +10,6 @@ export 'src/writer/queries/result_set_writer.dart';
 export 'src/writer/tables/data_class_writer.dart';
 export 'src/writer/tables/table_writer.dart';
 export 'src/writer/tables/update_companion_writer.dart';
-export 'src/writer/utils/hash_code.dart';
 export 'src/writer/utils/memoized_getter.dart';
-export 'src/writer/utils/override_equals.dart';
+export 'src/writer/utils/hash_and_equals.dart';
 export 'src/writer/writer.dart';

drift_dev/test/writer/utils/hash_code_test.dart

@@ -1,30 +1,42 @@
 import 'package:charcode/ascii.dart';
-import 'package:drift_dev/src/writer/utils/hash_code.dart';
+import 'package:drift_dev/src/writer/utils/hash_and_equals.dart';
 import 'package:test/test.dart';
 
 void main() {
   test('hash code for no fields', () {
     final buffer = StringBuffer();
-    const HashCodeWriter().writeHashCode([], buffer);
+    writeHashCode([], buffer);
     expect(buffer.toString(), r'identityHashCode(this)');
   });
 
-  test('hash code for a single field', () {
+  test('hash code for a single field - not a list', () {
     final buffer = StringBuffer();
-    const HashCodeWriter().writeHashCode(['a'], buffer);
+    writeHashCode([EqualityField('a')], buffer);
     expect(buffer.toString(), r'a.hashCode');
   });
 
+  test('hash code for a single field - list', () {
+    final buffer = StringBuffer();
+    writeHashCode([EqualityField('a', isList: true)], buffer);
+    expect(buffer.toString(), r'$driftBlobEquality.hash(a)');
+  });
+
   test('hash code for multiple fields', () {
     final buffer = StringBuffer();
-    const HashCodeWriter().writeHashCode(['a', 'b', 'c'], buffer);
-    expect(buffer.toString(), r'Object.hash(a, b, c)');
+    writeHashCode([
+      EqualityField('a'),
+      EqualityField('b', isList: true),
+      EqualityField('c'),
+    ], buffer);
+    expect(buffer.toString(), r'Object.hash(a, $driftBlobEquality.hash(b), c)');
   });
 
   test('hash code for lots of fields', () {
     final buffer = StringBuffer();
-    const HashCodeWriter().writeHashCode(
-        List.generate(26, (index) => String.fromCharCode($a + index)), buffer);
+    writeHashCode(
+        List.generate(
+            26, (index) => EqualityField(String.fromCharCode($a + index))),
+        buffer);
     expect(
       buffer.toString(),
       r'Object.hashAll([a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, '

drift_dev/test/writer/utils/override_equals_test.dart

@@ -1,4 +1,4 @@
-import 'package:drift_dev/src/writer/utils/override_equals.dart';
+import 'package:drift_dev/src/writer/utils/hash_and_equals.dart';
 import 'package:test/test.dart';
 
 void main() {
@@ -14,12 +14,17 @@ void main() {
 
   test('overrides equals on class with fields', () {
     final buffer = StringBuffer();
-    overrideEquals(['a', 'b', 'c'], 'Foo', buffer);
+    overrideEquals([
+      EqualityField('a'),
+      EqualityField('b', isList: true),
+      EqualityField('c'),
+    ], 'Foo', buffer);
 
     expect(
         buffer.toString(),
         '@override\nbool operator ==(Object other) => '
         'identical(this, other) || (other is Foo && '
-        'other.a == this.a && other.b == this.b && other.c == this.c);\n');
+        r'other.a == this.a && $driftBlobEquality.equals(other.b, this.b) && '
+        'other.c == this.c);\n');
   });
 }