Error using generics: cannot find type definition: T

[acim]

Describe the bug

In package httpx I have the following struct:

type Response[T any] struct {
    StatusCode int      `json:"-"`
    Data       *T       `json:"data,omitempty"`
    Errors     []string `json:"errors,omitempty"`
}

And in the handler in another package I have the following annotation:

// @success 200 {object} httpx.Response[[]person]

person is a struct within the same package where this annotation is.

When I try to run swag, I get the following error:

2022/10/12 21:05:08 ParseComment error in file /...redacted.../internal/handler/persons.go :cannot find type definition: T

To Reproduce
Steps to reproduce the behavior:

I believe this is also explained above.

Expected behavior
Swagger docs should be generated.

Your swag version
1.8.6

Your go version
1.19.2

Desktop (please complete the following information):

• OS: Linux

[JohnAD]

In a very similar vein (I'm also running Linux w go 1.19.2 and swag 1.8.6)

I have:

type JsonResponseStruct[T any] struct {
	Data  *DataObject[T] `json:"data,omitempty"`
	Error *ErrorObject   `json:"error,omitempty"`
}

type DataObject[T any] struct {
	CurrentItemCount int `json:"currentItemCount,omitempty"`
	Items            []T `json:"items"`
}

with

// @Success 200 {object} JsonResponseStruct[string]

I also tried:

type JsonResponseStruct[T any] struct {
	Data  *T           `json:"data,omitempty"`
	Error *ErrorObject `json:"error,omitempty"`
}

type DataObject[T any] struct {
	CurrentItemCount int `json:"currentItemCount,omitempty"`
	Items            []T `json:"items"`
}

with

// @Success 200 {object} JsonResponseStruct[DataObject[string]]

in the hope that a more blunt reference would do it. Go and Gin were happy with both.

In both cases I got:

PS C:\Users\jd\source\repos\apigwquery> make    
swag init
2022/10/13 08:30:22 Generate swagger docs....
2022/10/13 08:30:22 Generate general API Info, search dir:./
2022/10/13 08:30:27 Generating $main.JsonResponseStruct-main_DataObject_string
2022/10/13 08:30:27 ParseComment error in file C:\Users\jd\source\repos\apigwquery\main.go :cannot find type definition: T
make: *** [Makefile:9: swag-build] Error 1

[JohnAD]

Also took it to the extreme:

type JsonResponseStruct[T any] struct {
	Data  *T           `json:"data,omitempty"`
	Error *ErrorObject `json:"error,omitempty"`
}

type DataObject[T any] struct {
	CurrentItemCount int `json:"currentItemCount,omitempty"`
	Items            *T  `json:"items"`
}

and

// @Success 200 {object} JsonResponseStruct[DataObject[[]string]]

I'm kinda glad that didn't work as that would have been an ugly workaround. :)

OT: until a fix is found, I'm simply adding:

type JsonResponseString JsonResponseStruct[string]

and

// @Success 200 {object} JsonResponseString

which still creates an error:

swag init
2022/10/13 09:18:37 Generate swagger docs....
2022/10/13 09:18:37 Generate general API Info, search dir:./
2022/10/13 09:19:23 Generating main.JsonResponseString
2022/10/13 09:19:23 Generating $main.JsonResponseStruct-string
2022/10/13 09:19:23 Generating main.DataObject
2022/10/13 09:19:23 Type definition of type '*ast.IndexExpr' is not supported yet. Using 'object' instead. (%!s(<nil>))
2022/10/13 09:19:23 create docs.go at  docs/docs.go
2022/10/13 09:19:23 create swagger.json at  docs/swagger.json
2022/10/13 09:19:23 create swagger.yaml at  docs/swagger.yaml

but at least it defaults to a generic object and let's me compile. I'll live with not having the data structure in the swagger for now.

[JohnAD]

Possibly useful to programmers: if I use a second reference to the same generic (but with a different sub-type), I get:

2022/10/13 09:44:56 Skipping 'main.DataObject', recursion detected.

It's like it can't handle generics within generics as it is losing reference.

[sdghchj]

Could you please try the latest PR and give me some feedback?

[acim]

I have already tried fix-generics branch and it worked. Shall I still try the latest PR?

[sdghchj]

I have already tried fix-generics branch and it worked. Shall I still try the latest PR?

No need.

@JohnAD How about you?

[ekeyme]

I found that this behavior could also be reproduced in an environment with the new swag v1.8.8 on Linux go v1.19, BUT with swag v1.8.7 works well.

[raulvc]

still broken in v1.8.9 ... (linux go 1.19)
fixed in 1.8.10 (released a few minutes ago)