[New rule] Avoid using var

[mdeandrea-mrmilu]

Rule details

This rule should show warning when use var on code.
The style guide for Flutter indicate to avoid using var on code, so that will be a nice rule to have

What type of rule is this?

Warns about a potential problem

Example code

BAD:

var x = 10; // LINT

String concat(int a, int b) {
  var c = 3; // LINT
  return a + b + c;
}

GOOD:

int x = 10;

final x = 10;

String concat(int a, int b) {
  int c = 3; // or final c = 3;
  return a + b + c;
}

Participation

• I am willing to submit a pull request to implement this rule.

Additional comments

No response