Ace tern editor. Make own autocomplete properties for unknown value

Question

i have default.json file with properties. Example,

{
    "!name": "test",
    "Commit": {
        "!doc": "test",
        "!type": "fn(connectionName: string, k: string) -> object"
    
        "default": {
            "!doc": "test",
            "z": {
                 "!doc": "test"
                 },
            "p": {
                 "!doc": "test"
                 }
    }
}

In redactor

var t = 'string';
Commit.t.

and i need that autocomplete with 'default' properties appears after "t". So, if "Commit" dont have that property (in this case "t"), then properties 'z' and 'p' appear. how i can did it? thanks