bug: self.foo behaves different from foo in regards of null check with strict type checker

The following code doesn't compile with SDK 7.2.1 with type check = strict:

import Toybox.Application;
import Toybox.Lang;
import Toybox.WatchUi;

class TestApp extends Application.AppBase {
    public var foo as Number?;

    function initialize() {
        AppBase.initialize();
    }

    public function bar() as Void {
        if (self.foo != null) {
            // this doesn't compile
            self.foo.compareTo(3);
        }

        if (foo != null) {
            // this does compile
            foo.compareTo(3);
        }
    }
}

flocsy🤠

Brandon.ConnectIQ over 1 year ago

I talked with the compiler team, and we need to do some improvements to how we handle null checks. Either case in your example should work.
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9811827 over 1 year ago
Can't say much about "self", but I've noticed, that null check for class members works only for the first usage of member both using 6.4.2 and 7.2.0:
```
if (foo != null) {
    System.println(foo.toString()); // OK
    System.println(foo.toString()); // NOK
}
```
It is even worse:
```
if (foo != null) {
    System.println("bar");
    System.println(foo.toString()); // NOK
}
```
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