do_what_now library

Support for a functional approach to error handling.

One can return an instance of a DoWhat from any method and return either an What or a value. Values returned are defined by the Generic

DoWhats can also be created from any Object instance using the static create method. Null objects will return an What result while valid objects will return a DoWhat containing the valid Object of

Once a DoWhat is created a fluent API using extension methods can be leverage to handle the 'Do' (happy path) or 'What' (error path).

Classes

DoWhat<TValue>
The DoWhat type is the result of a method an object or method. Results can contain either a List<> of What or value of the specified type
What<TError>
Defines an error or issue that cause a DoWhat to return a failure. The error class can be implemented or extended to provide custom error type or
WhatEmpty<TValue>
WhatEmpty provides a default error to handle NULL refernces.
WhatException
WhatException stores an exception provided to the DoWhat
WhatMessage
WhatMessage stores a custom string provided to the DoWhat
WhatObject
WhatObject stores a custom object provided to the DoWhat

Enums

DoState
The resuting state of a DoWhat A result can only ever be pass or fail.
Why
Describes the type of error stored in the instance of the What class.

Extensions

ResultExtensions on DoWhat<TValue>
Extension methods designed to provide a fluent API These methods allow users to safely chain together DoWhats and safely continue on either the happy path or the sad path.
WhatErrorsExtension on List<What>
Extension methods used to work with collections of What objects.

Functions

combine<T1, T2>(DoWhat<T1> result1, DoWhat<T2> result2) → DoWhat<(T1, T2)>
Returns a tuple result.
create<TValue>(TValue value) → DoWhat<TValue>
Factory method to create a new result DoWhat from an instance of an object The create method will return a successful result only if the TValue is NOT null
empty<T>() → WhatEmpty
Creates a new WhatEmpty extending What of the Type T Returns a formmatted message describing the instance of T
exception(Exception ex) → WhatException
Creates a new WhatException extending What of the Type Exception Returns a formmatted message describing the instance of Exception
failure<TValue>(What error) → DoWhat<TValue>
Factory method to create a new failed DoWhat
failures<TValue>(List<What> errors) → DoWhat<TValue>
Factory method to create a new failed DoWhat with several errors
from<TValue>(TValue value, bool predicate(TValue value), {String? message}) → DoWhat<TValue>
Factory method to create a new DoWhat The from method will evaluate the value and execute the predicate. The DoWhat will be successfull if the callers predicate returns true.
message(String message) → WhatMessage
Creates a new WhatMessage extending What Returns a formmatted message describing the error
success<TValue>(TValue value) → DoWhat<TValue>
Factory method to create a new Successful DoWhat
what(Object obj) → WhatObject
Creates a new WhatObject extending What Returns a formmatted message describing the instance of the Object