danger_report_composite_subscription.dart

import 'dart:io';

import 'package:analyzer/dart/analysis/analysis_context_collection.dart';
import 'package:analyzer/dart/ast/ast.dart';
import 'package:analyzer/dart/ast/visitor.dart';
import 'package:danger_core/danger_core.dart';
import 'package:path/path.dart' as path;

enum _AnalysisVisitorType {
  listenWithoutAddTo,
  compositeAdd,
}

class _AnalysisVisitorResult {
  late final _AnalysisVisitorType type;
  late final int offset;

  _AnalysisVisitorResult(this.type, this.offset);
}

class _AnalysisVisitor extends RecursiveAstVisitor<int> {
  final result = <_AnalysisVisitorResult>[];

  @override
  int? visitMethodInvocation(MethodInvocation node) {
    final childEntities = node.childEntities.toList();
    if (childEntities.length > 2) {
      final methodName = childEntities[childEntities.length - 2].toString();
      if (methodName == 'listen') {
        result.add(_AnalysisVisitorResult(
            _AnalysisVisitorType.listenWithoutAddTo, childEntities[childEntities.length - 1].end));
        return null;
      }
    }
    if (childEntities.length > 3) {
      final firstMethod =
          childEntities[0].toString() + childEntities[1].toString() + childEntities[2].toString();
      if (firstMethod == 'compositeSubscription.add') {
        result.add(
            _AnalysisVisitorResult(_AnalysisVisitorType.compositeAdd, childEntities[0].offset));
        return null;
      }
    }
    return null;
  }
}

class DangerPluginReportListenToCompositeSubscription {
  static void process() {
    final allfiles = danger.git.createdFiles + danger.git.modifiedFiles;

    allfiles.where((file) => file.endsWith('.dart')).forEach((filePath) {
      final file = File(filePath);
      final lines = file.readAsLinesSync();

      final collection =
          AnalysisContextCollection(includedPaths: [path.normalize(file.absolute.path)]);
      collection.contexts.forEach((context) {
        context.contextRoot.analyzedFiles().forEach((analyzedFile) {
          final session = context.currentSession;
          final result = session.getParsedUnit(analyzedFile);
          final unit = result.unit;
          final visitor = _AnalysisVisitor();
          unit.accept(visitor);
          final errorResults = visitor.result;
          errorResults.forEach((errorResult) {
            final lineInfo = result.lineInfo.getLocation(errorResult.offset);
            final lineNo = lineInfo.lineNumber;

            switch (errorResult.type) {
              case _AnalysisVisitorType.compositeAdd:
                warn('Please use .listen().addTo(compositeSubscription);` instead',
                    file: filePath, line: lineNo + 1);
                break;
              case _AnalysisVisitorType.listenWithoutAddTo:
                warn('Don\'t forget to use `.addTo(compositeSubscription)` !!',
                    file: filePath, line: lineNo + 1);
                break;
            }
          });
        });
      });
    });
  }
}