CustomType defined on NestedObject within List/Map/Set Nested Attributes Raises Invalid Element Type Error

[bendbennett]

Module version

v1.3.4

Relevant provider source code

var _ basetypes.ObjectTypable

type ListNestedAttributeAssocExtType struct {
	basetypes.ObjectType
}

func (c ListNestedAttributeAssocExtType) Equal(o attr.Type) bool {
	other, ok := o.(ListNestedAttributeAssocExtType)

	if !ok {
		return false
	}

	return c.ObjectType.Equal(other.ObjectType)
}

func (c ListNestedAttributeAssocExtType) String() string {
	return "CustomObjectType"
}

func (c ListNestedAttributeAssocExtType) ValueFromObject(ctx context.Context, in basetypes.ObjectValue) (basetypes.ObjectValuable, diag.Diagnostics) {
	value := ListNestedAttributeAssocExtValue{
		ObjectValue: in,
	}

	return value, nil
}

func (c ListNestedAttributeAssocExtType) ValueFromTerraform(ctx context.Context, in tftypes.Value) (attr.Value, error) {
	attrValue, err := c.ObjectType.ValueFromTerraform(ctx, in)

	if err != nil {
		return nil, err
	}

	objectValue, ok := attrValue.(basetypes.ObjectValue)

	if !ok {
		return nil, fmt.Errorf("unexpected value type of %T", attrValue)
	}

	objectValuable, diags := c.ValueFromObject(ctx, objectValue)

	if diags.HasError() {
		return nil, fmt.Errorf("unexpected error converting ObjectValue to ObjectValuable: %v", diags)
	}

	return objectValuable, nil
}

func (c ListNestedAttributeAssocExtType) ValueType(ctx context.Context) attr.Value {
	return ListNestedAttributeAssocExtValue{}
}

var _ basetypes.ObjectValuable = ListNestedAttributeAssocExtValue{}

type ListNestedAttributeAssocExtValue struct {
	basetypes.ObjectValue
}

func (c ListNestedAttributeAssocExtValue) Equal(o attr.Value) bool {
	other, ok := o.(ListNestedAttributeAssocExtValue)

	if !ok {
		return false
	}

	return c.ObjectValue.Equal(other.ObjectValue)
}

func (c ListNestedAttributeAssocExtValue) Type(ctx context.Context) attr.Type {
	return ListNestedAttributeAssocExtType{
		basetypes.ObjectType{
			AttrTypes: map[string]attr.Type{
				"int64_attribute": types.Int64Type,
			},
		},
	}
}

func (e *exampleResource) Schema(ctx context.Context, req resource.SchemaRequest, resp *resource.SchemaResponse) {
	resp.Schema = schema.Schema{
		Attributes: map[string]schema.Attribute{
			"list_nested_attribute_assoc_ext_type": schema.ListNestedAttribute{
				Optional: true,
				NestedObject: schema.NestedAttributeObject{
					CustomType: ListNestedAttributeAssocExtType{
						ObjectType: types.ObjectType{
							AttrTypes: map[string]attr.Type{
								"int64_attribute": types.Int64Type,
							},
						},
					},
					Attributes: map[string]schema.Attribute{
						"int64_attribute": schema.Int64Attribute{
							Optional: true,
						},
					},
				},
			},
			/* ... */

type exampleResourceData struct {
	ListNestedAttributeAssocExtType types.List `tfsdk:"list_nested_attribute_assoc_ext_type"`
}

Terraform Configuration Files

resource "example_resource" "example" {
  list_nested_attribute_assoc_ext_type = [
    {
      int64_attribute = 1
    },
    {
      int64_attribute = 2
    }
  ]
}

Debug Output

https://gist.github.com/bendbennett/df35a80597f6b9df94a6a29793668695

Expected Behavior

terraform apply should run successfully.

Actual Behavior

terraform apply generates the following error:

│ Error: Invalid List Element Type
│ 
│   with example_resource.example,
│   on resource.tf line 9, in resource "example_resource" "example":
│    9: resource "example_resource" "example" {
│ 
│ While creating a List value, an invalid element was detected. A List must use the single, given element type. This is always an issue with the provider and should be reported to the provider developers.
│ 
│ List Element Type: CustomObjectType
│ List Index (0) Element Type: types.ObjectType["int64_attribute":basetypes.Int64Type]

Steps to Reproduce

1. terraform apply

References

• internal/fwserver: Ensure Attribute and Block plan modification returns custom value type implementations #768
• PlanModifiers on Custom Type NestedAttributeObject/NestedBlockObject #767

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