unnecessary_string_interpolations

Unnecessary string interpolation.

DON'T use string interpolation if there's only a string expression in it.

BAD:

String message;
String o = '$message';

GOOD:

String message;
String o = message;

To enable the unnecessary_string_interpolations rule, add unnecessary_string_interpolations under linter > rules in your analysis_options.yaml file:

linter:
  rules:
    - unnecessary_string_interpolations

If you're instead using the YAML map syntax to configure linter rules, add unnecessary_string_interpolations: true under linter > rules:

linter:
  rules:
    unnecessary_string_interpolations: true