prefer_shorthands

• Fix factory constructors with body return displayed warning that should not appeared. #21.

• Adapt return Future #19.

• Allow analyzer9.0.

• Remove a output statements that may cause the analyze server to crash.
• Adapt getter #16.
• Adapt Record #15.
• Enhance return type check for Iterable/Map/Record.

• Adapt List and Set.
• Adapt Map.
• Adapt operator !=.
• Add case DefaultFormalParameter (#8).
• Fix case when assignment to dynamic, like <String, dynamic>{}..**['a'] = Foo.a** (#11).
• Add case returnStatement and returnExpression (#9).
• Fix case subtype_prefix_in_supertype_context (see test file).

• Fix Size(100, 100) > Size.zero be wrong marning, the opearator > required righthand type is Size's Base Class, so here can't use shorthand. A similar situation is operator ??.
• Fix bugDog(Animal.dog());, .dog is Animal's constructor, but function need a Dog, so here can't use shorthand.

• Fix #5

• Add more case.
• Optimized code.
• Improved testing.

• Chore

• Fix quick-fix case:

class Animal {
    static Dog dog => ...;
}
class Dog extends Animal{}

void main() {
    final animal = Animal.dog; // wrong quick-fix to `final Dog animal = .dog;`
}

• The assignment behavior will now be correctly detected.

• Support settings convert_implicit_declaration, defaults to false.

• Fix case borderRadius: BorderRadius.all(.circular(16)),

• Fix.

• Fix case:

class Animal {}
class Dog extends Animal{
    static Dog husky() => ...;
}

void foo(Animal animal){}

void main() {
    foo(Dog.husky()); // should not warning
}

• Fix analyze argument list.

• Update README.md.

• Warning when not use dot shorthands!

• Fix.