Implement type inference for asserts in constructor initializers.

pkg/analyzer/test/src/task/strong/front_end_inference_test.dart

 // Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 import 'dart:async';
 import 'dart:convert';
 import 'dart:io';
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/token.dart';
 import 'package:analyzer/dart/ast/visitor.dart';
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/dart/element/type.dart';
 import 'package:analyzer/src/dart/analysis/driver.dart';
+import 'package:analyzer/src/generated/engine.dart' show AnalysisOptionsImpl;
 import 'package:analyzer/src/generated/parser.dart';
 import 'package:analyzer/src/generated/scanner.dart';
 import 'package:analyzer/src/generated/source.dart';
 import 'package:analyzer/src/generated/utilities_dart.dart';
 import 'package:front_end/src/base/instrumentation.dart' as fasta;
 import 'package:front_end/src/fasta/compiler_context.dart' as fasta;
 import 'package:front_end/src/fasta/testing/validating_instrumentation.dart'
     as fasta;
 import 'package:front_end/src/fasta/util/relativize.dart' show relativizeUri;
 import 'package:kernel/kernel.dart' as fasta;
@@ skipping 101 matching lines @@
     } else if (name.endsWith('=') &&
         element is PropertyAccessorElement &&
         element.isSetter) {
       name = name.substring(0, name.length - 1);
     }
     buffer.write(name);
   }
 }
 
 class _FrontEndInferenceTest extends BaseAnalysisDriverTest {
+  @override
+  AnalysisOptionsImpl createAnalysisOptions() =>
+      super.createAnalysisOptions()..enableAssertInitializer = true;
+
   Future<String> runTest(String path, String code) {
     return fasta.CompilerContext.runWithDefaultOptions((_) async {
       Uri uri = provider.pathContext.toUri(path);
 
       List<int> lineStarts = new LineInfo.fromContent(code).lineStarts;
       fasta.CompilerContext.current.uriToSource[relativizeUri(uri).toString()] =
           new fasta.Source(lineStarts, UTF8.encode(code));
 
       var validation = new fasta.ValidatingInstrumentation();
       await validation.loadExpectations(uri);
@@ skipping 494 matching lines @@
 
   /// Based on DDC code generator's `_recoverTypeArguments`
   Iterable<DartType> _recoverTypeArguments(FunctionType g, FunctionType f) {
     assert(identical(g.element, f.element));
     assert(g.typeFormals.isNotEmpty && f.typeFormals.isEmpty);
     assert(g.typeFormals.length + g.typeArguments.length ==
         f.typeArguments.length);
     return f.typeArguments.skip(g.typeArguments.length);
   }
 }