Warning if a function call is missing parenthesis

[kinex]

I wrote by accident a function call without the parenthesis at the end. I even copy/pasted this code to several places before I noticed it in my final code review. I would have expected to get a warning about this.

Example:

void foo() {
}

void foo2(int i) {
}


void main() {
  foo; // Warning should be shown for this line for an invalid function call
  foo();
  foo2; // Also this should give a warning
}

I know that a function reference is needed in some situations (like when passing a function as a parameter), but in the example above the situation is clear (only a function call makes sense).

Dart SDK version: 2.10.4 (stable)

[eernstg]

foo; in main is a perfectly executable and type correct statement, but I would expect that some tool could report that it does not have any effect.

The action taken is: Create a function object (a first class function) corresponding to the function declaration named foo, and then discard it.

It's no worse than 1; which will evaluate the given expression to an object representing the integer 1 and then discard it.

You may prefer to enable https://dart-lang.github.io/linter/lints/unnecessary_statements.html. I don't know if that's detecting exactly the kinds of no-op statements that you're focusing on, but it does make the analyzer output a diagnostic message about the two lines foo; and foo2;.

[kinex]

I know those are correct statements, but clearly they are statements the developer did not write on purpose. And in my case it resulted a medium level bug (a required function call ChangeNotifier.notifylisteners() was omitted).

unnecessary_statements seems to help! Thanks. Little surprising that I have to enable this rule manually (even though I use also pedantic package). After enabling that rule I found also one new similar issue in my code base.