v0.5.9

0.5.9

• Update the minimum Dart SDK to 1.22.1.

• Deprecated builder.dart: import source_gen.dart instead.

• Added TypeChecker, a high-level API for performing static type checks:

  import 'package:analyzer/dart/element/type.dart';
  import 'package:source_gen/source_gen.dart';
  
  void checkType(DartType dartType) {
    // Checks compared to runtime type `SomeClass`.
    print(const TypeChecker.forRuntime(SomeClass).isExactlyType(dartType));
    
    // Checks compared to a known Url/Symbol:
    const TypeChecker.forUrl('package:foo/foo.dart#SomeClass');
    
    // Checks compared to another resolved `DartType`:
    const TypeChecker.forStatic(anotherDartType);
  }

• Failing to add a library directive to a library that is being used as a
  generator target that generates partial files (part of) is now an explicit
  error that gives a hint on how to name and fix your library:

  > Could not find library identifier so a "part of" cannot be built.
  >
  > Consider adding the following to your source file:
  >
  > "library foo.bar;"

  In Dart SDK >=1.25.0 this can be relaxed as part of can refer to a path.
  To opt-in, GeneratorBuilder now has a new flag, requireLibraryDirective.
  Set it to false, and also set your sdk constraint appropriately:

    sdk: '>=1.25.0 <2.0.0'

• Added LibraryReader, a utility class for LibraryElement that exposes
  high-level APIs, including findType, which traverses export directives
  for publicly exported types. For example, to find Generator from
  package:source_gen/source_gen.dart:

  void example(LibraryElement pkgSourceGen) {
    var library = new LibraryReader(pkgSourceGen);
  
    // Instead of pkgSourceGen.getType('Generator'), which is null.
    library.findType('Generator');
  }

• Added ConstantReader, a high-level API for reading from constant (static)
  values from Dart source code (usually represented by DartObject from the
  analyzer package):

  abstract class ConstantReader {
    factory ConstantReader(DartObject object) => ...
  
    // Other methods and properties also exist.
  
    /// Reads[ field] from the constant as another constant value.
    ConstantReader read(String field);
  
    /// Reads [field] from the constant as a boolean.
    ///
    /// If the resulting value is `null`, uses [defaultTo] if defined.
    bool readBool(String field, {bool defaultTo()});
  
    /// Reads [field] from the constant as an int.
    ///
    /// If the resulting value is `null`, uses [defaultTo] if defined.
    int readInt(String field, {int defaultTo()});
  
    /// Reads [field] from the constant as a string.
    ///
    /// If the resulting value is `null`, uses [defaultTo] if defined.
    String readString(String field, {String defaultTo()});
  }