Analyzer gives confusing message when boolean expression has invalid assignment.

[dnfield]

bool confusing(Object b) {
  return b is int // Dart analyzer says: missing selector such as '.identifier' or '[0]' - line 2
      && b = 2;   // error is actually here - this should be `==`.
}

void main() {}

Reproduces in dartpad and in IDE. I'd expect to only see an error on line 3 (invalid assignment). I actually see an error on line 2 (in comment), followed by a couple more confusing messages on line 3 :

error
A value of type 'int can't be returned from function 'confusing' because it has a return type of 'bool' - line 2
error
Missing selector such as '.identifier' or '[0]' - line 2
error
The operands of the '&&' operator must be assignable to 'bool' - line 3
error
A value of type 'int' can't be assigned to a variable of type 'bool' - line 3

[dnfield]

The compiler gives a more sensible error, at least for app-jit snapshots:

../../packages/flutter_tools/lib/src/build_system/targets/icon_font_subset.dart:105:25: Error: Can't assign to this.
        && other.family = family
                        ^

[MichaelRFairhurst]

Seems like a very reasonable request. This is a common pattern in other languages and should prob give better output here.

@brianwilkerson

[jensjoha]

As indicated in a comment above the CFE gives this error message:

Error: Can't assign to this.
      && b = 2;   // error is actually here - this should be `==`.
           ^

This seems like an analyzer bug to me (which the title also says) so I'll but the "old labels" back.

[srawlins]

The errors remain today. Very strange errors.