Generated AutoMockable compilation issue due to variadic parameters

[rokridi]

Hello 👋

The current AutoMockable.stencil (version 2.1.7) does not properly handle methods with variadic parameters, which causes a compilation failure.

Example:

Given the following protocol:

// sourcery: AutoMockable
protocol ExampleVararg {
  func toto(args: any StubWithSomeNameProtocol...)
} 

The expected mock should like this:

var totoArgsAnyStubWithSomeNameProtocolVoidCallsCount = 0
var totoArgsAnyStubWithSomeNameProtocolVoidCalled: Bool {
  return totoArgsAnyStubWithSomeNameProtocolVoidCallsCount > 0
}
var totoArgsAnyStubWithSomeNameProtocolVoidReceivedArgs: ([(any StubWithSomeNameProtocol)])?
var totoArgsAnyStubWithSomeNameProtocolVoidReceivedInvocations: [[(any StubWithSomeNameProtocol)]] = []
var totoArgsAnyStubWithSomeNameProtocolVoidClosure: (([(any StubWithSomeNameProtocol)]) -> Void)?

func toto(args: any StubWithSomeNameProtocol...) {
  totoArgsAnyStubWithSomeNameProtocolVoidCallsCount += 1
  totoArgsAnyStubWithSomeNameProtocolVoidReceivedArgs = args
  totoArgsAnyStubWithSomeNameProtocolVoidReceivedInvocations.append(args)
  totoArgsAnyStubWithSomeNameProtocolVoidClosure?(args)
}

However it looks like this:

  var totoArgsAnyStubWithSomeNameProtocolVoidCallsCount = 0
  var totoArgsAnyStubWithSomeNameProtocolVoidCalled: Bool {
    return totoArgsAnyStubWithSomeNameProtocolVoidCallsCount > 0
  }
  var totoArgsAnyStubWithSomeNameProtocolVoidReceivedArgs: (any StubWithSomeNameProtocol...)?
  var totoArgsAnyStubWithSomeNameProtocolVoidReceivedInvocations: [(any StubWithSomeNameProtocol...)] = []
  var totoArgsAnyStubWithSomeNameProtocolVoidClosure: ((any StubWithSomeNameProtocol...) -> Void)?

  func toto(args: any StubWithSomeNameProtocol...) {
    totoArgsAnyStubWithSomeNameProtocolVoidCallsCount += 1
    totoArgsAnyStubWithSomeNameProtocolVoidReceivedArgs = args
    totoArgsAnyStubWithSomeNameProtocolVoidReceivedInvocations.append(args)
    totoArgsAnyStubWithSomeNameProtocolVoidClosure?(args)
  }

Note that for each method variadic parameter the corresponding received argument should be of type [ArgumentType] and not ArgumentType...

[rokridi]

Hello @art-divin

@pocketal and I are working on a fix for this issue.
We wonder if it is possible to add isVariadic information to closure parameter. We need that information to be able to handle variadic closure parameters.

[art-divin]

Hello @rokridi , @pocketal , this is very nice of you to invest your time into improving Sourcery 🤝

We wonder if it is possible to add isVariadic information to closure parameter

Let's see!

[art-divin]

a1343ff introduces isVariadic member to ClosureParameter. I am adding UTs for it; in the meanwhile, you could take the leverage using that implementation already 👍🏻

Edit: since Swift itself does not support variadic arguments for closures, it is unreasonable to add such implementation detail.

[art-divin]

@rokridi I would like to mention that acceptable implementation would be:

var totoArgsAnyStubWithSomeNameProtocolVoidCallsCount = 0
var totoArgsAnyStubWithSomeNameProtocolVoidCalled: Bool {
  return totoArgsAnyStubWithSomeNameProtocolVoidCallsCount > 0
}
var totoArgsAnyStubWithSomeNameProtocolVoidReceivedArgs: ([(any StubWithSomeNameProtocol)])?
var totoArgsAnyStubWithSomeNameProtocolVoidReceivedInvocations: [[(any StubWithSomeNameProtocol)]] = []
var totoArgsAnyStubWithSomeNameProtocolVoidClosure: (([(any StubWithSomeNameProtocol)]) -> Void)?

func toto(args: any StubWithSomeNameProtocol...) {
  totoArgsAnyStubWithSomeNameProtocolVoidCallsCount += 1
  totoArgsAnyStubWithSomeNameProtocolVoidReceivedArgs = args
  totoArgsAnyStubWithSomeNameProtocolVoidReceivedInvocations.append(args)
  totoArgsAnyStubWithSomeNameProtocolVoidClosure?(args)
}

i.e. keeping any and parentheses around the type, as opposed to the expected result in the OP.

[art-divin]

I am not 100% sure you actually need ClosureParameter.isVariadic, rather, try simply to modify AutoMockable.stencil template like here:

{% macro existentialClosureVariableTypeName typeName isVariadic -%}
    {%- if typeName|contains:"any " and typeName|contains:"!" -%}
        {{ typeName | replace:"any","(any" | replace:"!",")?" }}
    {%- elif typeName|contains:"any " and typeName.isClosure and typeName|contains:"?" -%}
        {{ typeName | replace:"any","(any" | replace:"?",")?" }}
    {%- elif typeName|contains:"any " and typeName|contains:"?" -%}
        {{ typeName | replace:"any","(any" | replace:"?",")?" }}
    {%- elif typeName|contains:"some " and typeName|contains:"!" -%}
        {{ typeName | replace:"some","(any" | replace:"!",")?" }}
    {%- elif typeName|contains:"some " and typeName.isClosure and typeName|contains:"?" -%}
        {{ typeName | replace:"some","(any" | replace:"?",")?" }}
    {%- elif typeName|contains:"some " and typeName|contains:"?" -%}
        {{ typeName | replace:"some","(any" | replace:"?",")?" }}
    {%- elif isVariadic -%}
-        {{ typeName }}...
+        [{{ typeName }}]
    {%- else -%}
        {{ typeName|replace:"some ","any " }}
    {%- endif -%}
{%- endmacro %}

[rokridi]

@art-divin thanks for replying. I updated the issue's description.
The actual stencil has issues. It does not handle closures with existential parameters properly. The macros need to be re-written.
Here is an example of a function having a parameter which is a closure having a variadic parameter:

func foo(closure: (String...) -> Void)

But this case is tricky to handle.

[art-divin]

@rokridi thank you, I see. So the branch I've referred above should support ClosureParameter.isVariadic. Please check

[rokridi]

Here is what the Stencil could look like (AutoMockable.txt), however we did not succeed at handling functions having a parameter which is a closure having a variadic parameter.

Example:

func foo(closure: (String...) -> Void)

The corresponding mock:

    var func13ParamStringVoidVoidClosure: (((String) -> Void) -> Void)?
    func func13(param: (String) -> Void) {
        func13ParamStringVoidVoidCallsCount += 1
        func13ParamStringVoidVoidClosure?(param)
    }

Expected mock:

    var func13ParamStringVoidVoidClosure: (((String...) -> Void) -> Void)?
    func func13(param: (String...) -> Void) {
        func13ParamStringVoidVoidCallsCount += 1
        func13ParamStringVoidVoidClosure?(param)
    }

[art-divin]

@rokridi

var func13ParamStringVoidVoidClosure: (((String...) -> Void) -> Void)?

This is not compilable swift - checked yesterday also, to my amusement, variadic is only supported in function signature, does not work with variables.

So, it'd work as:

    var func13ParamStringVoidVoidClosure: ((([(String)]) -> Void) -> Void)?

[art-divin]

I can pick it up from here, feel free to take a look at other, easy to reproduce bugs that are to be fixed for the next release:
https://github.com/krzysztofzablocki/Sourcery/milestone/6

[rokridi]

This PR should fix the issue