Optionally override hashCode and equals in result sets

docs/content/en/docs/Advanced Features/builder_options.md

@@ -25,4 +25,7 @@ At the moment, moor supports these options:
 
 * `write_from_json_string_constructor`: boolean. Adds a `.fromJsonString` factory
    constructor to generated data classes. By default, we only write a `.fromJson`
-   constructor that takes a `Map<String, dynamic>`.
+   constructor that takes a `Map<String, dynamic>`.
+* `overrride_hash_and_equals_in_result_sets`: boolean. When moor generates another class
+   to hold the result of generated select queries, this flag controls whether moor should
+   override `operator ==` and `hashCode` in those classes.

extras/plugin_example/README.md

@@ -24,6 +24,7 @@ have already cloned the `moor` repository.
    }
    ```
 6. Close that editor.
+7. Uncomment the plugin lines in `analysis_options.yaml`
   
 ## Running
 After you completed the setup, these steps will open an editor instance that runs the plugin.

extras/plugin_example/analysis_options.yaml

@@ -1,5 +1,5 @@
 include: package:pedantic/analysis_options.yaml
 
-analyzer:
-  plugins:
-    - moor
+#analyzer:
+#  plugins:
+#    - moor

moor/build.yaml

@@ -3,4 +3,4 @@ targets:
     builders:
       moor_generator:
         options:
-          generate_private_watch_methods: true
+          overrride_hash_and_equals_in_result_sets: true

moor/example/example.g.dart

@@ -6,7 +6,7 @@ part of 'example.dart';
 // MoorGenerator
 // **************************************************************************
 
-// ignore_for_file: unnecessary_brace_in_string_interps
+// ignore_for_file: unnecessary_brace_in_string_interps, unnecessary_this
 class Category extends DataClass implements Insertable<Category> {
   final int id;
   final String description;
@@ -66,7 +66,9 @@ class Category extends DataClass implements Insertable<Category> {
   @override
   bool operator ==(other) =>
       identical(this, other) ||
-      (other is Category && other.id == id && other.description == description);
+      (other is Category &&
+          other.id == this.id &&
+          other.description == this.description);
 }
 
 class CategoriesCompanion extends UpdateCompanion<Category> {
@@ -253,10 +255,10 @@ class Recipe extends DataClass implements Insertable<Recipe> {
   bool operator ==(other) =>
       identical(this, other) ||
       (other is Recipe &&
-          other.id == id &&
-          other.title == title &&
-          other.instructions == instructions &&
-          other.category == category);
+          other.id == this.id &&
+          other.title == this.title &&
+          other.instructions == this.instructions &&
+          other.category == this.category);
 }
 
 class RecipesCompanion extends UpdateCompanion<Recipe> {
@@ -479,9 +481,9 @@ class Ingredient extends DataClass implements Insertable<Ingredient> {
   bool operator ==(other) =>
       identical(this, other) ||
       (other is Ingredient &&
-          other.id == id &&
-          other.name == name &&
-          other.caloriesPer100g == caloriesPer100g);
+          other.id == this.id &&
+          other.name == this.name &&
+          other.caloriesPer100g == this.caloriesPer100g);
 }
 
 class IngredientsCompanion extends UpdateCompanion<Ingredient> {
@@ -691,9 +693,9 @@ class IngredientInRecipe extends DataClass
   bool operator ==(other) =>
       identical(this, other) ||
       (other is IngredientInRecipe &&
-          other.recipe == recipe &&
-          other.ingredient == ingredient &&
-          other.amountInGrams == amountInGrams);
+          other.recipe == this.recipe &&
+          other.ingredient == this.ingredient &&
+          other.amountInGrams == this.amountInGrams);
 }
 
 class IngredientInRecipesCompanion extends UpdateCompanion<IngredientInRecipe> {
@@ -874,4 +876,12 @@ class TotalWeightResult {
     this.title,
     this.totalWeight,
   });
+  @override
+  int get hashCode => $mrjf($mrjc(title.hashCode, totalWeight.hashCode));
+  @override
+  bool operator ==(other) =>
+      identical(this, other) ||
+      (other is TotalWeightResult &&
+          other.title == this.title &&
+          other.totalWeight == this.totalWeight);
 }

moor/test/data/tables/custom_tables.g.dart

@@ -6,7 +6,7 @@ part of 'custom_tables.dart';
 // MoorGenerator
 // **************************************************************************
 
-// ignore_for_file: unnecessary_brace_in_string_interps
+// ignore_for_file: unnecessary_brace_in_string_interps, unnecessary_this
 class NoId extends DataClass implements Insertable<NoId> {
   final Uint8List payload;
   NoId({@required this.payload});
@@ -55,7 +55,8 @@ class NoId extends DataClass implements Insertable<NoId> {
   int get hashCode => $mrjf(payload.hashCode);
   @override
   bool operator ==(other) =>
-      identical(this, other) || (other is NoId && other.payload == payload);
+      identical(this, other) ||
+      (other is NoId && other.payload == this.payload);
 }
 
 class NoIdsCompanion extends UpdateCompanion<NoId> {
@@ -190,7 +191,7 @@ class WithDefault extends DataClass implements Insertable<WithDefault> {
   @override
   bool operator ==(other) =>
       identical(this, other) ||
-      (other is WithDefault && other.a == a && other.b == b);
+      (other is WithDefault && other.a == this.a && other.b == this.b);
 }
 
 class WithDefaultsCompanion extends UpdateCompanion<WithDefault> {
@@ -354,7 +355,10 @@ class WithConstraint extends DataClass implements Insertable<WithConstraint> {
   @override
   bool operator ==(other) =>
       identical(this, other) ||
-      (other is WithConstraint && other.a == a && other.b == b && other.c == c);
+      (other is WithConstraint &&
+          other.a == this.a &&
+          other.b == this.b &&
+          other.c == this.c);
 }
 
 class WithConstraintsCompanion extends UpdateCompanion<WithConstraint> {
@@ -536,8 +540,8 @@ class Config extends DataClass implements Insertable<Config> {
   bool operator ==(other) =>
       identical(this, other) ||
       (other is Config &&
-          other.configKey == configKey &&
-          other.configValue == configValue);
+          other.configKey == this.configKey &&
+          other.configValue == this.configValue);
 }
 
 class ConfigCompanion extends UpdateCompanion<Config> {
@@ -699,8 +703,8 @@ class MytableData extends DataClass implements Insertable<MytableData> {
   bool operator ==(other) =>
       identical(this, other) ||
       (other is MytableData &&
-          other.someid == someid &&
-          other.sometext == sometext);
+          other.someid == this.someid &&
+          other.sometext == this.sometext);
 }
 
 class MytableCompanion extends UpdateCompanion<MytableData> {

moor/test/data/tables/todos.g.dart

@@ -6,7 +6,7 @@ part of 'todos.dart';
 // MoorGenerator
 // **************************************************************************
 
-// ignore_for_file: unnecessary_brace_in_string_interps
+// ignore_for_file: unnecessary_brace_in_string_interps, unnecessary_this
 class TodoEntry extends DataClass implements Insertable<TodoEntry> {
   final int id;
   final String title;
@@ -113,11 +113,11 @@ class TodoEntry extends DataClass implements Insertable<TodoEntry> {
   bool operator ==(other) =>
       identical(this, other) ||
       (other is TodoEntry &&
-          other.id == id &&
-          other.title == title &&
-          other.content == content &&
-          other.targetDate == targetDate &&
-          other.category == category);
+          other.id == this.id &&
+          other.title == this.title &&
+          other.content == this.content &&
+          other.targetDate == this.targetDate &&
+          other.category == this.category);
 }
 
 class TodosTableCompanion extends UpdateCompanion<TodoEntry> {
@@ -355,7 +355,9 @@ class Category extends DataClass implements Insertable<Category> {
   @override
   bool operator ==(other) =>
       identical(this, other) ||
-      (other is Category && other.id == id && other.description == description);
+      (other is Category &&
+          other.id == this.id &&
+          other.description == this.description);
 }
 
 class CategoriesCompanion extends UpdateCompanion<Category> {
@@ -560,11 +562,11 @@ class User extends DataClass implements Insertable<User> {
   bool operator ==(other) =>
       identical(this, other) ||
       (other is User &&
-          other.id == id &&
-          other.name == name &&
-          other.isAwesome == isAwesome &&
-          other.profilePicture == profilePicture &&
-          other.creationTime == creationTime);
+          other.id == this.id &&
+          other.name == this.name &&
+          other.isAwesome == this.isAwesome &&
+          other.profilePicture == this.profilePicture &&
+          other.creationTime == this.creationTime);
 }
 
 class UsersCompanion extends UpdateCompanion<User> {
@@ -801,7 +803,9 @@ class SharedTodo extends DataClass implements Insertable<SharedTodo> {
   @override
   bool operator ==(other) =>
       identical(this, other) ||
-      (other is SharedTodo && other.todo == todo && other.user == user);
+      (other is SharedTodo &&
+          other.todo == this.todo &&
+          other.user == this.user);
 }
 
 class SharedTodosCompanion extends UpdateCompanion<SharedTodo> {
@@ -988,9 +992,9 @@ class TableWithoutPKData extends DataClass
   bool operator ==(other) =>
       identical(this, other) ||
       (other is TableWithoutPKData &&
-          other.notReallyAnId == notReallyAnId &&
-          other.someFloat == someFloat &&
-          other.custom == custom);
+          other.notReallyAnId == this.notReallyAnId &&
+          other.someFloat == this.someFloat &&
+          other.custom == this.custom);
 }
 
 class TableWithoutPKCompanion extends UpdateCompanion<TableWithoutPKData> {
@@ -1183,7 +1187,7 @@ class PureDefault extends DataClass implements Insertable<PureDefault> {
   @override
   bool operator ==(other) =>
       identical(this, other) ||
-      (other is PureDefault && other.id == id && other.txt == txt);
+      (other is PureDefault && other.id == this.id && other.txt == this.txt);
 }
 
 class PureDefaultsCompanion extends UpdateCompanion<PureDefault> {
@@ -1433,6 +1437,28 @@ class AllTodosWithCategoryResult {
     this.catId,
     this.catDesc,
   });
+  @override
+  int get hashCode => $mrjf($mrjc(
+      id.hashCode,
+      $mrjc(
+          title.hashCode,
+          $mrjc(
+              content.hashCode,
+              $mrjc(
+                  targetDate.hashCode,
+                  $mrjc(category.hashCode,
+                      $mrjc(catId.hashCode, catDesc.hashCode)))))));
+  @override
+  bool operator ==(other) =>
+      identical(this, other) ||
+      (other is AllTodosWithCategoryResult &&
+          other.id == this.id &&
+          other.title == this.title &&
+          other.content == this.content &&
+          other.targetDate == this.targetDate &&
+          other.category == this.category &&
+          other.catId == this.catId &&
+          other.catDesc == this.catDesc);
 }
 
 // **************************************************************************

moor_generator/lib/src/backends/build/generators/moor_generator.dart

@@ -13,9 +13,8 @@ class MoorGenerator extends Generator implements BaseGenerator {
     final writer = builder.createWriter();
 
     if (parsed.declaredDatabases.isNotEmpty) {
-      writer
-          .leaf()
-          .write('// ignore_for_file: unnecessary_brace_in_string_interps\n');
+      writer.leaf().write(
+          '// ignore_for_file: unnecessary_brace_in_string_interps, unnecessary_this\n');
     }
 
     for (var db in parsed.declaredDatabases) {

moor_generator/lib/src/backends/build/options.dart

@@ -2,15 +2,22 @@ part of 'moor_builder.dart';
 
 class MoorOptions {
   final bool generateFromJsonStringConstructor;
+  final bool overrideHashAndEqualsInResultSets;
 
-  MoorOptions(this.generateFromJsonStringConstructor);
+  MoorOptions(this.generateFromJsonStringConstructor,
+      this.overrideHashAndEqualsInResultSets);
 
   factory MoorOptions.fromBuilder(Map<String, dynamic> config) {
     final writeFromString =
         config['write_from_json_string_constructor'] as bool ?? false;
 
-    return MoorOptions(writeFromString);
+    final overrideInResultSets =
+        config['overrride_hash_and_equals_in_result_sets'] as bool ?? false;
+
+    return MoorOptions(writeFromString, overrideInResultSets);
   }
 
-  const MoorOptions.defaults() : generateFromJsonStringConstructor = false;
+  const MoorOptions.defaults()
+      : generateFromJsonStringConstructor = false,
+        overrideHashAndEqualsInResultSets = false;
 }

moor_generator/lib/src/writer/queries/query_writer.dart

@@ -52,8 +52,8 @@ class QueryWriter {
     if (query is SqlSelectQuery) {
       final select = query as SqlSelectQuery;
       if (select.resultSet.needsOwnClass) {
-        final buffer = scope.findScopeOfLevel(DartScope.library).leaf();
-        ResultSetWriter(select).write(buffer);
+        final resultSetScope = scope.findScopeOfLevel(DartScope.library);
+        ResultSetWriter(select, resultSetScope).write();
       }
       _writeSelect();
     } else if (query is UpdatingQuery) {

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

@@ -1,13 +1,20 @@
 import 'package:moor_generator/src/model/sql_query.dart';
+import 'package:moor_generator/src/writer/utils/hash_code.dart';
+import 'package:moor_generator/src/writer/utils/override_equals.dart';
+import 'package:moor_generator/src/writer/writer.dart';
 
 /// Writes a class holding the result of an sql query into Dart.
 class ResultSetWriter {
   final SqlSelectQuery query;
+  final Scope scope;
 
-  ResultSetWriter(this.query);
+  ResultSetWriter(this.query, this.scope);
 
-  void write(StringBuffer into) {
+  void write() {
     final className = query.resultClassName;
+    final columnNames =
+        query.resultSet.columns.map(query.resultSet.dartNameFor).toList();
+    final into = scope.leaf();
 
     into.write('class $className {\n');
     // write fields
@@ -19,9 +26,20 @@ class ResultSetWriter {
 
     // write the constructor
     into.write('$className({');
-    for (var column in query.resultSet.columns) {
-      into.write('this.${query.resultSet.dartNameFor(column)},');
+    for (var column in columnNames) {
+      into.write('this.$column,');
     }
-    into.write('});\n}\n');
+    into.write('});\n');
+
+    // if requested, override hashCode and equals
+    if (scope.writer.options.overrideHashAndEqualsInResultSets) {
+      into.write('@override int get hashCode => ');
+      const HashCodeWriter().writeHashCode(columnNames, into);
+      into.write(';\n');
+
+      overrideEquals(columnNames, className, into);
+    }
+
+    into.write('}\n');
   }
 }

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

@@ -1,5 +1,6 @@
 import 'package:moor_generator/src/model/specified_table.dart';
 import 'package:moor_generator/src/writer/utils/hash_code.dart';
+import 'package:moor_generator/src/writer/utils/override_equals.dart';
 import 'package:moor_generator/src/writer/writer.dart';
 import 'package:recase/recase.dart';
 
@@ -50,24 +51,11 @@ class DataClassWriter {
     _writeToString();
     _writeHashCode();
 
-    // override ==
-    //    return identical(this, other) || (other is DataClass && other.id == id && ...)
-    _buffer
-      ..write('@override\nbool operator ==(other) => ')
-      ..write('identical(this, other) || (other is ${table.dartTypeName}');
+    overrideEquals(table.columns.map((c) => c.dartGetterName),
+        table.dartTypeName, _buffer);
 
-    if (table.columns.isNotEmpty) {
-      _buffer
-        ..write('&&')
-        ..write(table.columns.map((c) {
-          final getter = c.dartGetterName;
-
-          return 'other.$getter == $getter';
-        }).join(' && '));
-    }
-
-    // finish overrides method and class declaration
-    _buffer.write(');\n}');
+    // finish class declaration
+    _buffer.write('}');
   }
 
   void _writeMappingConstructor() {
@@ -224,7 +212,7 @@ class DataClassWriter {
     _buffer.write('@override\n int get hashCode => ');
 
     final fields = table.columns.map((c) => c.dartGetterName).toList();
-    HashCodeWriter().writeHashCode(fields, _buffer);
+    const HashCodeWriter().writeHashCode(fields, _buffer);
     _buffer.write(';');
   }
 

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

@@ -2,6 +2,8 @@ const _hashCombine = '\$mrjc';
 const _hashFinish = '\$mrjf';
 
 class HashCodeWriter {
+  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) {

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

@@ -0,0 +1,18 @@
+/// 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 ==(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');
+}

moor_generator/test/writer/utils/hash_code_test.dart

@@ -4,19 +4,19 @@ import 'package:test_api/test_api.dart';
 void main() {
   test('hash code for no fields', () {
     final buffer = StringBuffer();
-    HashCodeWriter().writeHashCode([], buffer);
+    const HashCodeWriter().writeHashCode([], buffer);
     expect(buffer.toString(), r'identityHashCode(this)');
   });
 
   test('hash code for a single field', () {
     final buffer = StringBuffer();
-    HashCodeWriter().writeHashCode(['a'], buffer);
+    const HashCodeWriter().writeHashCode(['a'], buffer);
     expect(buffer.toString(), r'$mrjf(a.hashCode)');
   });
 
   test('hash code for multiple fields', () {
     final buffer = StringBuffer();
-    HashCodeWriter().writeHashCode(['a', 'b', 'c'], buffer);
+    const HashCodeWriter().writeHashCode(['a', 'b', 'c'], buffer);
     expect(buffer.toString(),
         r'$mrjf($mrjc(a.hashCode, $mrjc(b.hashCode, c.hashCode)))');
   });

moor_generator/test/writer/utils/override_equals_test.dart

@@ -0,0 +1,25 @@
+import 'package:moor_generator/src/writer/utils/override_equals.dart';
+import 'package:test/test.dart';
+
+void main() {
+  test('overrides equals on class without fields', () {
+    final buffer = StringBuffer();
+    overrideEquals([], 'Foo', buffer);
+
+    expect(
+        buffer.toString(),
+        '@override\nbool operator ==(other) => '
+        'identical(this, other) || (other is Foo);\n');
+  });
+
+  test('overrides equals on class with fields', () {
+    final buffer = StringBuffer();
+    overrideEquals(['a', 'b', 'c'], 'Foo', buffer);
+
+    expect(
+        buffer.toString(),
+        '@override\nbool operator ==(other) => '
+        'identical(this, other) || (other is Foo && '
+        'other.a == this.a && other.b == this.b && other.c == this.c);\n');
+  });
+}