Invalid const constructor calls produce multiple diagnostics where one would do

[DanTup]

There are several tests in pkg/analyzer/test/src/dart/constant/evaluation_test.dart (once https://dart-review.googlesource.com/c/sdk/+/399661 has landed) that test code with invalid constants. In some cases they produce multiple diagnostics that overlap or are close together that are all related to the same issue. It would be nice if these could be combined (or the redundant ones discarded).

For example:

    await assertErrorsInCode('''
class A {
  const A({required int x });
}
class B extends A {
  const B({required super.x });
}
const a = B();
''', [
      error(CompileTimeErrorCode.MISSING_REQUIRED_ARGUMENT, 106, 1),
      error(CompileTimeErrorCode.CONST_INITIALIZED_WITH_NON_CONSTANT_VALUE, 106,
          3),
      error(CompileTimeErrorCode.INVALID_CONSTANT, 106, 3,
          contextMessages: [message(testFile, 88, 1)]),
    ]);

    await assertErrorsInCode('''
class A {
  const A(int x);
}
class B extends A {
  const B(super.x);
}
const a = B();
''', [
      error(CompileTimeErrorCode.NOT_ENOUGH_POSITIONAL_ARGUMENTS_NAME_SINGULAR,
          84, 1),
      error(CompileTimeErrorCode.CONST_INITIALIZED_WITH_NON_CONSTANT_VALUE, 82,
          3),
      error(CompileTimeErrorCode.INVALID_CONSTANT, 82, 3,
          contextMessages: [message(testFile, 66, 1)]),
    ]);

[FMorschel]

Some days ago I started taking a look at:

• dart fix should remove consts when they err just as it adds them when needed #49818
• [Analyzer] No quick-fix for "Invalid constant value." #47532
• Automatically removing const for non-constant related errors #53599

And the first one already had a draft on their issue. It also mentions (on the CL tests) that:

class A {
  const A();
}
class B {}
var v = const [A(), B()];

Triggers both NON_CONSTANT_LIST_ELEMENT and CONST_WITH_NON_CONST. And similar here:

class A {
  const A();
}
class B {}
var v = const {1: A(), 2: B()};

Where both CONST_WITH_NON_CONST and NON_CONSTANT_MAP_VALUE trigger.

And similarly for NON_CONSTANT_SET_ELEMENT:

class A {
  const A();
}
class B {}
var v = const {A(), B()};

Also, lastly:

class A {
  const A();
  A.nonConst();
}
// Notice that the `x` is `const` here
const x = [A(), A.nonConst()];

Triggers: CONST_WITH_NON_CONST, NON_CONSTANT_LIST_ELEMENT and the CONST_INITIALIZED_WITH_NON_CONSTANT_VALUE (which IMO is the right one here but I might be wrong).

---

Edit

I'm not sure of a case where CONST_WITH_NON_CONST is triggered alone but I haven't looked at the tests.