Unless conflict does not work on two-field indexes?

I get this error with UNLESS CONFLICT ON (.field1, .field):

edgedb.errors.QueryError: ON CONFLICT argument must be a property

And this error on UNLESS CONFLICT ON .field1, .field2:

edgedb.errors.EdgeQLSyntaxError: Unexpected ','

I.e. it look like not a bug, but just syntactically incorrect

[elprans]

@Mulugruntz, this is currently set for the 1.0 milestone, but chances are we can get support for matching constraints with expressions in UNLESS CONFLICT into the next beta.

[msullivan]

Oh, I had meant to update this: we don’t yet support a direct syntax for this, but there is a simple workaround: use a computed property.

So with a schema like

type Entry {                                                              
    required property field1 -> str;                                      
    required property field2 -> int64;                                    
    required property field3 -> bool;                                     
    property key {                                                        
        using ((.field1, .field2));                                       
        constraint exclusive;                                             
    };                                                                    
}

You can do queries like

INSERT Entry { field1 := "test", field2 := 42, field3 := false } 
UNLESS CONFLICT ON (.key)
ELSE (UPDATE Entry SET { field3 := true });