Add LimitedBinaryPrinter, tests and switch incremental generator to it.

pkg/front_end/test/incremental_kernel_generator_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 'package:front_end/compiler_options.dart';
 import 'package:front_end/incremental_kernel_generator.dart';
 import 'package:front_end/memory_file_system.dart';
 import 'package:front_end/src/incremental/byte_store.dart';
+import 'package:front_end/src/incremental/limited_ast_to_binary.dart';
+import 'package:front_end/src/incremental_kernel_generator_impl.dart';
 import 'package:kernel/ast.dart';
+import 'package:kernel/binary/ast_from_binary.dart';
 import 'package:kernel/text/ast_to_text.dart';
+import 'package:kernel/verifier.dart';
 import 'package:test/test.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
 
 import 'src/incremental/mock_sdk.dart';
 
 main() {
   defineReflectiveSuite(() {
     defineReflectiveTests(IncrementalKernelGeneratorTest);
   });
 }
@@ skipping 203 matching lines @@
         _getLibraryText(library),
         r'''
 library;
 import self as self;
 import "dart:core" as core;
 
 static field (core::String) → core::int f;
 ''');
   }
 
+  test_limited_ast_to_binary() async {
+    writeFile('/test/.packages', 'test:lib/');
+    String aPath = '/test/lib/a.dart';
+    String bPath = '/test/lib/b.dart';
+    writeFile(
+        aPath,
+        r'''
+int topField = 0;
+int get topGetter => 0;
+int topFunction({p}) => 0;
+        
+class A {
+  static int staticField;
+  static int get staticGetter => 0;
+  static int staticMethod() => 0;
+
+  int instanceField;
+  int get instanceGetter => 0;
+  int instanceMethod() => 0;
+  
+  A();
+  A.named();
+}
+''');
+    Uri bUri = writeFile(
+        bPath,
+        r'''
+import 'a.dart';
+
+class B extends A {
+  B() : super();
+  B.named() : super.named();
+  
+  void foo() {
+    super.instanceMethod();
+    instanceMethod();
+  }
+  
+  int instanceMethod() => 0;
+}
+
+main() {
+  topField;
+  topField = 0;
+  var v1 = topGetter;
+  var v2 = topFunction(p: 0);
+
+  A.staticField;
+  A.staticField = 0;
+  var v3 = A.staticGetter;
+  var v4 = A.staticMethod();
+
+  var a = new A();
+  a.instanceField;
+  a.instanceField = 0;
+  var v5 = a.instanceGetter;
+  var v6 = a.instanceMethod();
+}
+''');
+
+    Program initialProgram = await getInitialState(bUri);
+
+    String initialKernelText;
+    List<int> bytes;
+    {
+      Library initialLibrary = _getLibrary(initialProgram, bUri);
+      initialKernelText = _getLibraryText(initialLibrary);
+
+      var byteSink = new ByteSink();
+      var printer = new LimitedBinaryPrinter(
+          byteSink, (library) => library.importUri == bUri);
+      printer.writeProgramFile(initialProgram);
+      bytes = byteSink.builder.takeBytes();
+
+      // Remove b.dart from the initial program.
+      // So, the program is now ready for re-adding the library.
+      initialProgram.libraries.remove(initialLibrary);
+      initialProgram.root.removeChild(initialLibrary.importUri.toString());
+    }
+

[ahe, 2017/05/22 09:27:05]

Can you check that b.dart has been removed here?

[scheglov, 2017/05/22 20:36:01]

I'm not sure what we will verify by doing this.

That libraries.remove(initialLibrary) worked?
I think this test would belong to List unit test.

That root.removeChild(initialLibrary.importUri.toString()) removed its child?
Again, this is something to test in CanonicalName unit test, which does not
exist, but I'd be happy to add it, if this is what you mean by your comment.

[ahe, 2017/05/24 08:35:59]

I guess you're right. I'm just looking for some way to validate that you
actually read the new version of b.dart.

+    // Load b.dart from bytes using the initial name root, so that
+    // serialized canonical names can be linked to corresponding nodes.
+    Library loadedLibrary;
+    {
+      var programForLoading = new Program(nameRoot: initialProgram.root);
+      var reader = new BinaryBuilder(bytes);
+      reader.readProgram(programForLoading);
+      loadedLibrary = _getLibrary(programForLoading, bUri);
+    }
+
+    // Add the library into the initial program.
+    initialProgram.libraries.add(loadedLibrary);
+    loadedLibrary.parent = initialProgram;
+
+    // The loaded library has the same text.
+    expect(_getLibraryText(loadedLibrary), initialKernelText);
+
+    // The program with re-added library passes verification.
+    verifyProgram(initialProgram);
+  }
+
   test_updateEntryPoint() async {
     writeFile('/test/.packages', 'test:lib/');
     String path = '/test/lib/test.dart';
     Uri uri = writeFile(
         path,
         r'''
 main() {
   var v = 1;
 }
 ''');
@@ skipping 178 matching lines @@
     throw fail('No library found with URI "$uri"');
   }
 
   String _getLibraryText(Library library) {
     StringBuffer buffer = new StringBuffer();
     new Printer(buffer, syntheticNames: new NameSystem())
         .writeLibraryFile(library);
     return buffer.toString();
   }
 }