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BatMap - The Mapper we deserve, not the one we need.

🦇 BatMap Opininated (yet another) mapper, mainly to convert between EF Entities and DTOs.

Supports .Net Standard 1.0.

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Let's first obey the number one rule for mappers, a benchmark (using BenchmarkDotNet):

Method Mean
HandWritten 1.143 ms
BatMap 💥 2.000 ms
SafeMapper 2.933 ms
Mapster 2.942 ms
AutoMapper 3.497 ms
TinyMapper 4.172 ms
ExpressMapper 6.955 ms
FastMapper 9.203 ms

Results may (probably) vary. Latest run can bee seen on Appveyor Build.

  • Fast (enough)
  • NOT over-engineered, code is really simple
  • Instantiatable mapper
  • Convention based, zero configuration static shortcut exists too (obviously named Mapper)
  • Does not crash when faced with circular-dependencies during registration
  • In fact, can resolve recurring instances to same target instance (yaay no StackOverflowException!)
  • Can project IQueryable<TSource> to IQueryable<TTarget> with respect to includes (via auto-detection or with custom parameters)
  • and much more...


Registration with static API:

Mapper.RegisterMap<Customer, CustomerDTO>();

or use an instance:

var mapper = new MapConfiguration(dynamicMapping: DynamicMapping.MapAndCache, preserveReferences: true);
mapper.RegisterMap<Customer, CustomerDTO>();

Note: You don't have to register type mappings when using a MapConfiguration with Dynamic Mapping enabled (like the static API uses).

You can customize expressions for members:

mapper.RegisterMap<Order, OrderDTO>(b => b.MapMember(o => o.Price, (o, mc) => o.Count * o.UnitPrice));

Map an object:


Map an enumerable:

customers.MapTo<Customer, CustomerDTO>(preserveReferences: true);  // extension methods FTW!

Project a query:

customerQuery.ProjectTo<CustomerDTO>(checkIncludes: true);

or with expanding specific navigations:

customerQuery.ProjectTo<Customer, CustomerDTO>(c => c.Addresses, c => c.Orders);

Note: If you want to change mapping behavior, create a class that inherits from ExpressionProvider, override CreateMemberBinding and inject an instance of your class to MapConfiguration.

Where can I get it?

You can install BatMap from the package manager console:

PM> Install-Package BatMap


You might want to visit wiki for more.

Developed with ❤️ at Doğuş Teknoloji.