Migrating from other libraries

Mapping Injectio and AutoRegisterInject attributes and defaults onto Immediate.Injections.

2 min read

Both libraries below register services from attributes, so the mechanical translation is small. The part that bites is the default registration strategy: Immediate.Injections defaults to registering a class as itself, where the others do not. Set an assembly default first, then port the attributes.

From Injectio

Set this first

Injectio's default is "self and interfaces, sharing one instance". Reproduce it with

[assembly: RegistrationDefaults(RegistrationStrategy = RegistrationStrategy.SelfAndImplementedInterfaces, UseProxyFactory = true)]

before you touch anything else. Without UseProxyFactory you get one instance per service type instead of one shared instance.

AssemblyInfo.cs

using Immediate.Injections.Shared;

[assembly: RegistrationDefaults(
	RegistrationStrategy = RegistrationStrategy.SelfAndImplementedInterfaces,
	UseProxyFactory = true
)]

Injectio	Immediate.Injections
`[RegisterSingleton]`, `[RegisterScoped]`, `[RegisterTransient]`	Same names
`Registration = ...`	`RegistrationStrategy = ...`
`RegistrationStrategy.SelfWithInterfaces`	`RegistrationStrategy.SelfAndImplementedInterfaces`
`Duplicate = ...`	`DuplicateStrategy = ...`
`Tags = "foo,bar"` (comma-separated string)	`Tags = ["foo", "bar"]` (string array)
Assembly-name override via MSBuild property	`[assembly: ImmediateAssemblyIdentifier("Name")]`

The tag change is the one to grep for — Tags = "foo,bar" will not compile against a string[]? property, so the compiler finds them all for you.

Warning

[ImmediateAssemblyIdentifier] is defined in the Immediate.Handlers package, not this one. If you are not also using Immediate.Handlers you must either add a reference to it or declare a matching type yourself — see The assembly identifier.

From AutoRegisterInject

Set this first

AutoRegisterInject registers a class against its interfaces, not against itself. Reproduce that with [assembly: RegistrationDefaults(RegistrationStrategy = RegistrationStrategy.ImplementedInterfaces)].

AssemblyInfo.cs

using Immediate.Injections.Shared;

[assembly: RegistrationDefaults(
	RegistrationStrategy = RegistrationStrategy.ImplementedInterfaces
)]

AutoRegisterInject	Immediate.Injections
`[RegisterSingleton]`, `[RegisterScoped]`, `[RegisterTransient]`	Same names
`[TryRegisterSingleton]` and friends	`[RegisterSingleton(DuplicateStrategy = DuplicateStrategy.Skip)]`

The TryRegisterXxx family has no equivalent attribute; the “only register if absent” behavior is now a property, so a [TryRegisterScoped<IService>] becomes:

[RegisterScoped<IService>(DuplicateStrategy = DuplicateStrategy.Skip)]

If most of your registrations were TryRegisterXxx, set the assembly default instead and drop the property from each attribute:

[assembly: RegistrationDefaults(
	RegistrationStrategy = RegistrationStrategy.ImplementedInterfaces,
	DuplicateStrategy = DuplicateStrategy.Skip
)]

After either migration

Replace the old library’s startup call with the generated AddXxxServices().
Build once and read the diagnostics. INJ0003–INJ0012 catch most translation mistakes at compile time; see Diagnostics.
Registrations that silently vanish rather than erroring are almost always a generic class with a Factory or UseProxyFactory — see Open generics.