Make arrays use concrete types, not aliases.

[jkj]

Currently when you create an array type using something like:

components:
  schemas:
    my_item:
      type: object
      properties:
        name:
          type: string
        age:
          type: integer
    example:
      type: array
      items:
        $ref: '#/components/schemas/my_item'

the generator produces a type alias for the array:

// Example defines model for example.
type Example = []MyItem

This causes problems, particularly for defining methods. This patch ensures that when arrays are generated, they use a concrete type and not a type alias. For example:

// Example defines model for example.
type Example []MyItem

The following example indicates why aliases are bad:

type item struct {
        name string
        age int
}

type Alias = []item
type Concrete []item

// func (*Alias) wont_compile() {
//     invalid receiver type *[]item
// }

func (*Concrete) will_compile() {
}

This is especially problematic if you need to create methods for things like a JSON Scan() method or an SQL Value() method for the type.

[jamietanna]

Thanks for raising this @jkj - this will be a breaking change, so we'd need to mark this behind an output-options feature flag, so folks can opt-in to this behaviour. Would you be OK to make the change?

[zsolt-p]

need to create methods for things like a JSON Scan() method or an SQL Value() method for the type.

I have this same exact use case, too.

my workaround is:

• add the schema to my spec anyway (I do this so I can still $ref the type, etc)
• -exclude-schemas=mySchema when I generate
• implement the concrete type by hand outside the genned code within the same package, where I can implement its methods, etc