Hey @rubensayshi, can you please share an example that break the compatibility and why the current solution is not enough for migration (from #1428):

After this change, users that use a GoType(&T{}) will get *T in all generated interfaces (instead of T). However, if users still want to use values (instead of pointers), they can pass T{} to GoType (e.g. GoType(T{})), even if T doesn't implement the sql.Scanner interface (but *T does).

@a8m you always ask good questions <3

if you're reliant on schema/snapshot and had GoType(&T) and upgraded ent then you can run in to this issue.

if necessary I can make a demo project for you if you'd like, but maybe just showing the json in internal/schema.go and the resulting messed up code will do ;)

I have this field:

		field.String("rate").
			SchemaType(map[string]string{dialect.Postgres: rateNumeric}).
			GoType(&decimal.Decimal{}),

This is what is in my schema json for this field from an earlier version of ent:

        {
          "name": "rate",
          "type": {
            "Type": 7,
            "Ident": "decimal.Decimal",
            "PkgPath": "github.com/shopspring/decimal",
            "Nillable": true,
            "RType": {
              "Name": "Decimal",
              "Ident": "",
              "Kind": 25,
              "PkgPath": "github.com/shopspring/decimal",
              "Methods": {}
            }
          },
          "position": {
            "Index": 1,
            "MixedIn": false,
            "MixinIndex": 0
          },
          "schema_type": {
            "postgres": "numeric(12, 6)"
          }
        },

but atm when I want to re generate the code I get the following output for scanValues

// scanValues returns the types for scanning values from sql.Rows.
func (*AuctionOrder) scanValues(columns []string) ([]interface{}, error) {
	values := make([]interface{}, len(columns))
	for i := range columns {
		switch columns[i] {
				case entauctionorder.FieldRate:
					values[i] = new()

I think this is simply because for some reason the older version of ent we were using was creating a schema json with the RType.Ident left blank (newer version actually sets it properly).
Tbh I haven't looked too deep into why it was leaving RType.Ident blank, maybe there aren't too many people with this issue ...

I'm not sure how others do this, but to avoid a myriad of issues we had in the past, we actually put most ent files on gitignore and regenerate when we switch branches / add new fields or entities. thus always forcing the usage of the schema json.
(we only keep the ent/generate.go, ent/schema and ent/internal).

Because of this we hit this problem with the schema json BC break.

A temporary fix for me was to regenerate the ent files with the old version of ent, and then without first removing the gitignored files regenerate it with the new version. then it doesn't need to use the schema json and will create a fresh and proper schema json.

I think anyone who uses the same approach could have this issue upgrading, or someone who upgraded and was doing schema changes at the same time (which is a bad idea, but you know ... people do the weirdest things :P)

Maybe just updating the title and description of this issue to hopefully direct anyone else running into this issue and reading that they should just do things step by step will actually suffice for now?
Or if they read this and it doesn't solve their issue we can reopen this?

to leave a breadcrumb for anyone else who got the same issue, I got this error while doing go generate:

format file ent/auctionorder.go: ent/auctionorder.go:158:34: expected type, found ')'