Diagnostic analyzers and code fix providers

Support diagnostics (declaration):

• Analyze if method has Async suffix
• Analyze if method has CancellationToken parameter
• Analyze if method's CancellationToken has name cancellationToken
• Analyze if CancellationToken is last parameter in method

Contains CodeFixes (declaration):

• Rename method name without Async suffix
• Add missing CancellationToken cancellationToken parameter
• Rename CancellationToken parameter to cancellationToken when name is not matched
• Reorder method parameters and put CancellationToken as last parameter

Support diagnostics (invocation):

• Analyze if invoked method has Async suffix
• Analyze if invoked method has CancellationToken parameter
  • checks if CancellationToken parameter is present in scope where asynchronous method is invoked and add possibility to use it
  • add possibility to enhance declaration and use CancellationToken.None

Contains CodeFixes (invocation):

• Rename method name without Async suffix
• Add missing CancellationToken cancellationToken parameter
  • Add cancellation token to declaration and invocation (CancellationToken.None)
  • Add cancellation token to declaration and invocation (reuse cancellationToken from method scope where is invoked)

Analyzed methods

Declaration:

• async void method declarations
• Task method declarations
• async Task method declarations
• Task<T> method declarations
• async Task<T> method declarations

Invocation:

• async void method invocations
• Task method invocations
• async Task method invocations
• Task<T> method invocations
• async Task<T> method invocations

Examples Declaration vs. Invocation

Example Declaration:

public Task MyMethod() // => Declaration analyzers analyzers will rise diagnostics
{
}

Example Invocation:

public Task MyMethod()
{
      return AnotherAsyncMethod(); // => invocation analyzers analyzers will rise diagnostics
}

TO DO

• refactorings to remove code duplicity
• improve Texts
• add another analyzers and codefixes
  • reorder Func<T,....> generics when CancellationToken is detected
  • reorder Action<T,....> generics when CancellationToken is detected
  • detect and convert async void methods to Task methods
• improve automatic simplification
• add test code :D