Explicitly define flow signature in effe.go

[maratori]

Summary

Let's change signature of the flow description in such way to explicitly define dependencies, arguments and return values.

Description

Description is based on test SimpleWIthDependencies.
Flow A is described in effe.go.
It implicitly defines:

• dependencies = arguments of NewAImpl
• arguments = arguments of AFunc
• return values = return values of AFunc

Implicitly means that none of the above is defined in effe.go, but generates by cli tool.
And reader of effe.go file doesn't understand what they are.

I propose to change signature of flow function to be

func MyFLow([dependencies...]) func([arguments...]) [return values...] {
	effe.BuildFlow(...)
	return nil
}

So instead of generation signatures of NewAImpl and AFunc generator will just check that they match flow description.

Example

Test SimpleWIthDependencies will be changed.
FIles steps.go and effe_gen.go will remain the same.
File effe.go will be changed to

func A(UserRepository, NotificationRepository) func(string) error {
	effe.BuildFlow(
		effe.Step(step1),
		effe.Step(step2),
	)
	return nil
}

from

effe/testdata/SimpleWIthDependencies/foo/effe.go

Lines 7 to 13 in d8f24ab

	func A() error {
	effe.BuildFlow(
	effe.Step(step1),
	effe.Step(step2),
	)
	return nil
	}