Inlined interfaces

[nikolaydubina]

Description

Purpose

Avoid declaring non exported upstream interfaces as separate types just so they can be mocked.

Details

https://go.dev/play/p/Bt74sBt01Yl

package main

import "fmt"

// go generate mockery Employee.address

// struct with interface
type Employee struct {
	address interface {
		StreetName() string
		BlockNumber() int
	}
}

// constructor with inlined interface
func NewEmployee(
	address interface {
		StreetName() string
		BlockNumber() int
	},
) Employee {
	return Employee{address: address}
}

// concerete upstream
type HumanAddress struct {
	streetName  string
	blockNumber int
}

func (h HumanAddress) StreetName() string { return h.streetName }

func (h HumanAddress) BlockNumber() int { return h.blockNumber }

func main() {
	e := NewEmployee(HumanAddress{streetName: "some-street", blockNumber: 11})
	fmt.Printf("%#v", e)
}

[nikolaydubina]

I think I can implement this, if no takers!

[LandonTClipp]

Can you create a proposal of how this would be implemented? Mockery would need to generate some named mock implementation of the inlined interface. I fear whatever implementation you have is going to be kind of messy, but I'm open to hear what you think.

[nikolaydubina]

I see, so the concern here is that mockery does not have suitable abstractions for this? ok! noted. I did not look into code yet. I think if it is fast enough to hack, will make PR. But if lots of work, then will ping you guys here again. Cheers ! 🤝

…

On Sat, 4 Feb 2023 at 07:09, Landon Clipp ***@***.***> wrote: Can you create a proposal of how this would be implemented? Mockery would need to generate some named mock implementation of the inlined interface. I fear whatever implementation you have is going to be kind of messy, but I'm open to hear what you think. — Reply to this email directly, view it on GitHub <#531 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAWMCRMMZU3VT7ILEBFY223WVWF3TANCNFSM6AAAAAAUCFL3KM> . You are receiving this because you authored the thread.Message ID: ***@***.***>

[LandonTClipp]

The problem is moreso that mockery searches a package's global scope for named interface types. If an interface definition lies inline a function signature, mockery would then need to also inspect the function signature of every top-level function. It would then need to also assign a name to that interface. It's not an impossible task, but it's not as simple as you might think.

[LandonTClipp]

Going to close this as we won't be implementing it.