support the array of custom type

[tokubass]

I want to get this sample code supported.

func TestArrayOfCustomType(t *testing.T) {
        type MyInt int
        type Sample struct {
                Value  []MyInt
        }

        val := Sample{}

        err := FakeData(&val)
        if err != nil {
                t.Errorf("%v", err)
        }
}

 $ go test -v ./... -run TestArrayOfCustomType
=== RUN   TestArrayOfCustomType
--- FAIL: TestArrayOfCustomType (0.00s)
panic: reflect.Set: value of type int is not assignable to type faker.MyInt [recovered]
	panic: reflect.Set: value of type int is not assignable to type faker.MyInt

goroutine 34 [running]:
testing.tRunner.func1(0xc00011c100)
	/Users/user/.goenv/versions/1.12beta1/src/testing/testing.go:827 +0x387
panic(0x1151620, 0xc000090780)
	/Users/user/.goenv/versions/1.12beta1/src/runtime/panic.go:522 +0x1b7
reflect.Value.assignTo(0x1150be0, 0xc0000982a0, 0x82, 0x1193bf5, 0xb, 0x1150ba0, 0x0, 0x58, 0xc000124000, 0x17)
	/Users/user/.goenv/versions/1.12beta1/src/reflect/value.go:2338 +0x425
reflect.Value.Set(0x1150ba0, 0xc000124000, 0x182, 0x1150be0, 0xc0000982a0, 0x82)
	/Users/user/.goenv/versions/1.12beta1/src/reflect/value.go:1472 +0xa7
github.com/bxcodec/faker/v3.getValue(0x114e220, 0xc0000a6720, 0x197, 0x1, 0x114e220, 0xc0000a6720, 0x197)
	/Users/user/git/faker/faker.go:411 +0xd92
github.com/bxcodec/faker/v3.getValue(0x1163780, 0xc0000a66e0, 0x199, 0x1163701, 0x1163780, 0xc0000a66e0, 0x135b5f0)
	/Users/user/git/faker/faker.go:375 +0x1eef
github.com/bxcodec/faker/v3.getValue(0x1148840, 0xc0000a66a0, 0x0, 0xc000098288, 0x1, 0xc0000386f8, 0x100bdf4)
	/Users/user/git/faker/faker.go:335 +0x16a1
github.com/bxcodec/faker/v3.FakeData(0x1148840, 0xc0000a66a0, 0x1049128, 0x28dc6f6812e)
	/Users/user/git/faker/faker.go:260 +0x1c5
github.com/bxcodec/faker/v3.TestArrayOfCustomType(0xc00011c100)
	/Users/user/git/faker/faker_test.go:934 +0x4b
testing.tRunner(0xc00011c100, 0x119fb30)
	/Users/user/.goenv/versions/1.12beta1/src/testing/testing.go:862 +0xbf
created by testing.(*T).Run
	/Users/user/.goenv/versions/1.12beta1/src/testing/testing.go:913 +0x356
FAIL	github.com/bxcodec/faker/v3	0.013s
?   	github.com/bxcodec/faker/v3/support/slice	[no test files]

[bxcodec]

I'm afraid this feature is a bit impossible, as I stated here: https://github.com/bxcodec/faker#limitation

I will grateful if someone can give solutions for this issue.

[andrew-werdna]

So due to a recent PR that was merged, what you are asking is now possible as long as you add a custom tag to your struct and use AddProvider() to implement what happens when you use that tag.
@bxcodec & @tokubass

Example:

type MyInt int
type Sample struct {
	Value  []MyInt `faker:"myint"` // <- the custom tag
}
func TestArrayOfCustomType(t *testing.T) {
		a := Sample{}
		sliceLen := 10
		err := AddProvider("myint", func(v reflect.Value) (interface{}, error) { 
			s1 := rand.NewSource(time.Now().UnixNano())
			r1 := rand.New(s1)
			r := make([]MyInt, sliceLen)
			for i := range r {
				r[i] = MyInt(r1.Intn(100))
			}
			return r, nil
		})
                /** ^ above is the AddProvider for the tag "myint".  
                  * It simply makes a slice of length 10 and fills it with random numbers. 
                  * That is the implementation for what happens when you use the tag.
                  */
		if err != nil {
			t.Error("Expected Not Error, But Got: ", err)
		}

		err = FakeData(&a)

		if err != nil {
			t.Error("Expected Not Error, But Got: ", err)
		}

		if len(a.Value) != sliceLen {
			t.Errorf("Expected a slice of length %v but got %v", sliceLen, len(a.Value))
		}

	}

[andrew-werdna]

This fix currently only works for types of array & slice. I can submit a PR that will extend this behavior to more types shortly (aliasing an existing built-in type to a user defined type).
Edited: ^ I was ignorant of some existing code. I have added a unit test for the OP's situation, but as explained in the previous comment, just use AddProvider() to ensure it's created properly

[andrew-werdna]

@bxcodec I think you can close this issue as the OP's desire is now supported with the caveat of using AddProvider() to make sure the custom type gets created properly.