Generate code to help sorting db rows

codegen/lib/np_codegen.dart

@@ -1,3 +1,4 @@
 library np_codegen;
 
+export 'src/drift_table_sort_annotations.dart';
 export 'src/np_log_annotations.dart';

codegen/lib/src/drift_table_sort_annotations.dart

@@ -0,0 +1,6 @@
+class DriftTableSort {
+  const DriftTableSort(this.dbClass);
+
+  final String dbClass;
+}
+

codegen_build/build.yaml

@@ -1,9 +1,9 @@
 builders:
   np_log_build:
     import: "package:np_codegen_build/builder.dart"
-    builder_factories: ["npLogBuilder"]
+    builder_factories: ["driftTableSortBuilder", "npLogBuilder"]
     # The `partId` argument to `SharedPartBuilder` is "some_cool_builder"
-    build_extensions: {".dart": [".np_log.g.part"]}
+    build_extensions: {".dart": [".np_codegen.g.part"]}
     auto_apply: dependents
     build_to: cache
     # To copy the `.g.part` content into `.g.dart` in the source tree

codegen_build/lib/builder.dart

@@ -1,6 +1,10 @@
 import 'package:build/build.dart';
+import 'package:np_codegen_build/src/drift_table_sort_generator.dart';
 import 'package:np_codegen_build/src/np_log_generator.dart';
 import 'package:source_gen/source_gen.dart';
 
+Builder driftTableSortBuilder(BuilderOptions options) =>
+    SharedPartBuilder([DriftTableSortGenerator()], "drift_table_sort");
+
 Builder npLogBuilder(BuilderOptions options) =>
     SharedPartBuilder([NpLogGenerator()], "np_log");

codegen_build/lib/src/drift_table_sort_generator.dart

@@ -0,0 +1,71 @@
+import 'package:analyzer/dart/element/element.dart';
+import 'package:build/build.dart';
+import 'package:np_codegen/np_codegen.dart';
+import 'package:source_gen/source_gen.dart';
+
+/// Generate a enum class with all columns to define sorting without exposing
+/// drift internals
+class DriftTableSortGenerator extends GeneratorForAnnotation<DriftTableSort> {
+  const DriftTableSortGenerator();
+
+  @override
+  dynamic generateForAnnotatedElement(
+    Element element,
+    ConstantReader annotation,
+    BuildStep buildStep,
+  ) {
+    if (element is! ClassElement) {
+      print("Not a class");
+      return null;
+    }
+    final driftTableSort =
+        DriftTableSort(annotation.read("dbClass").stringValue);
+    final clazz = element;
+    if (!clazz.allSupertypes.any((t) => t.element2.name == "Table")) {
+      print("Not a drift table");
+      return null;
+    }
+    final columns = clazz.fields.where((f) => _shouldIncludeField(f)).toList();
+    if (columns.isEmpty) {
+      print("No columns");
+      return null;
+    }
+
+    final sortEnumName =
+        "${clazz.name.substring(0, clazz.name.length - 1)}Sort";
+    final enumValues = columns
+        .map((f) => "${f.name}Asc, ${f.name}Desc, ")
+        .reduce((a, b) => a + b);
+    final cases = columns.map((f) {
+      return """
+case $sortEnumName.${f.name}Asc:
+  return OrderingTerm.asc(db.${clazz.name.replaceRange(0, 1, clazz.name[0].toLowerCase())}.${f.name});
+case $sortEnumName.${f.name}Desc:
+  return OrderingTerm.desc(db.${clazz.name.replaceRange(0, 1, clazz.name[0].toLowerCase())}.${f.name});
+""";
+    }).reduce((a, b) => a + b);
+    return """
+enum $sortEnumName { $enumValues }
+
+extension ${sortEnumName}IterableExtension on Iterable<$sortEnumName> {
+  Iterable<OrderingTerm> toOrderingItem(${driftTableSort.dbClass} db) {
+    return map((s) {
+      switch (s) { $cases }
+    });
+  }
+}
+""";
+  }
+
+  bool _shouldIncludeField(FieldElement field) {
+    if (!field.isSynthetic) {
+      // columns are getters
+      return false;
+    }
+    // it's a very rough way but well...
+    if (field.type.element2?.name?.endsWith("Column") ?? false) {
+      return true;
+    }
+    return false;
+  }
+}

codegen_build/pubspec.yaml

@@ -17,6 +17,7 @@ dependencies:
 dev_dependencies:
   build_test: ^2.1.5
   lints: any
+  path: any
   test: any
   code_gen_tester:
     git:

codegen_build/test/drift_table_sort_test.dart

@@ -0,0 +1,88 @@
+import 'package:np_codegen_build/src/drift_table_sort_generator.dart';
+import 'package:test/test.dart';
+
+import 'util.dart';
+
+void main() {
+  resolveCompilationUnit("test/src/drift_table_sort.dart");
+  tearDown(() {
+    // Increment this after each test so the next test has it's own package
+    _pkgCacheCount++;
+  });
+
+  test("DriftTableSort", () {
+    final src = _genSrc("""
+@DriftTableSort("Database")
+class Tests extends Table {
+  IntColumn get test1 => integer()();
+  TextColumn get test2 => text()();
+}
+
+class Table {}
+
+class IntColumn {}
+
+class TextColumn {}
+
+IntColumn Function() integer() => () => IntColumn();
+
+TextColumn Function() text() => () => TextColumn();
+""");
+    final expected = _genExpected(r"""
+enum TestSort {
+  test1Asc,
+  test1Desc,
+  test2Asc,
+  test2Desc,
+}
+
+extension TestSortIterableExtension on Iterable<TestSort> {
+  Iterable<OrderingTerm> toOrderingItem(Database db) {
+    return map((s) {
+      switch (s) {
+        case TestSort.test1Asc:
+          return OrderingTerm.asc(db.tests.test1);
+        case TestSort.test1Desc:
+          return OrderingTerm.desc(db.tests.test1);
+        case TestSort.test2Asc:
+          return OrderingTerm.asc(db.tests.test2);
+        case TestSort.test2Desc:
+          return OrderingTerm.desc(db.tests.test2);
+      }
+    });
+  }
+}
+""");
+    return _buildTest(src, expected);
+  });
+}
+
+String _genSrc(String src) {
+  return """
+import 'package:np_codegen/np_codegen.dart';
+part 'test.g.dart';
+$src
+""";
+}
+
+String _genExpected(String src) {
+  return """// GENERATED CODE - DO NOT MODIFY BY HAND
+
+part of 'test.dart';
+
+// **************************************************************************
+// DriftTableSortGenerator
+// **************************************************************************
+
+$src""";
+}
+
+Future _buildTest(String src, String expected) => buildTest(
+      generators: [DriftTableSortGenerator()],
+      pkgName: _pkgName,
+      src: src,
+      expected: expected,
+    );
+
+String get _pkgName => 'pkg$_pkgCacheCount';
+int _pkgCacheCount = 1;

codegen_build/test/src/drift_table_sort.dart

@@ -0,0 +1,4 @@
+import 'package:np_codegen/np_codegen.dart';
+
+@DriftTableSort("")
+class Foo {}

codegen_build/test/util.dart

@@ -0,0 +1,34 @@
+import 'dart:io';
+
+import 'package:build/build.dart';
+import 'package:build_test/build_test.dart';
+import 'package:path/path.dart' as p;
+import 'package:source_gen/source_gen.dart';
+
+// Taken from source_gen_test, unclear why this is needed...
+Future<void> resolveCompilationUnit(String filePath) async {
+  final assetId = AssetId.parse('a|lib/${p.basename(filePath)}');
+  final files =
+      Directory(p.dirname(filePath)).listSync().whereType<File>().toList();
+
+  final fileMap = Map<String, String>.fromEntries(files.map(
+      (f) => MapEntry('a|lib/${p.basename(f.path)}', f.readAsStringSync())));
+
+  await resolveSources(fileMap, (item) async {
+    return await item.libraryFor(assetId);
+  }, resolverFor: 'a|lib/${p.basename(filePath)}');
+}
+
+Future buildTest({
+  required List<Generator> generators,
+  required String pkgName,
+  required String src,
+  required String expected,
+}) {
+  return testBuilder(
+    PartBuilder(generators, ".g.dart"),
+    {"$pkgName|lib/test.dart": src},
+    generateFor: {'$pkgName|lib/test.dart'},
+    outputs: {"$pkgName|lib/test.g.dart": decodedMatches(expected)},
+  );
+}