Exist Check on Primitive Types rather than checking if they has been set to a non-zero value

[DDDDarrenWB]

SDK version

v2.24.0

Use-cases

Example field,

Schema: map[string]*schema.Schema{
			"enable_example": {
				Type:        schema.TypeBool,
				Optional:    true,
				Description: 'Specifies whether the test field is enabled'
			},
}

Example API,

type ExampleConfig struct {
	// Mode: Mode defines enablement mode for Example features.
	//
	// Possible values:
	//   "UNSPECIFIED" - Default value not specified.
	//   "Disabled" - Disables Example features.
	//   "Enabled" - Enable Example features.
	Mode string `json:"mode,omitempty"`

	ForceSendFields []string `json:"-"`

	NullFields []string `json:"-"`
}

The field is of a boolean type. We want to map field values to the API config like below,

1. enable_example field not set by user ------> UNSPECIFIED
2. enable_example field is set to TRUE ------> Enabled
3. enable_example field is set to FALSE ------> DISABLED

By doing *ResourceData.Get() or *ResourceData.GetOk(), they either return zero value for primitive types or check whether or not the key has been set to a non-zero value at some point. For boolean, it's false.

We need a Exist flag to determine if a primitive field is set by user in the configuration.

Attempted Solutions

N/A

Proposal

Maybe the following function can be implemented to return both value and exist in configuration.

func (d *ResourceData) GetExist(key string) (value interface{}, exist bool)

References

Similar issue: #784