Support for DiffSuppressFunc on schema.TypeMap

Is the schema DiffSuppressFunc ignored for schema.TypeMap ? If so, is this by design, just not implemented yet, or perhaps a defect?

Even with the following, Terraform still detects changes to the “properties” map:

			"properties": &schema.Schema{
				Type:     schema.TypeMap,
				Optional: true,
				Elem: &schema.Schema{
					Type:     schema.TypeString,
					Required: true,
					DiffSuppressFunc: func(k, old, new string, d *schema.ResourceData) bool{
						return true
				Default: map[string]string{},

You may need the DiffSuppressFunc to be on the properties schema.Schema, not the schema.Schema of its Elem.

The docs don’t say, as far as I can tell, that this isn’t supported, but I haven’t checked the code yet to find out whether it’s run. Usually we see DiffSuppressFuncs on primitive types, I think.

If moving the DiffSuppressFunc to the outer schema.Schema doesn’t solve the problem, I’d suggest filing an issue, because it’ll take some investigation to get to the bottom of this and find an answer.