Linting rules

E002: unused-variable

Checks for variables and parameters that are declared but never used.

Metadata

Checks for variables and parameters that are declared but never used.

Unused variables and parameters clutter the code and can be a sign of a bug.

fun main() {
    val x = 1;E002: variable is unused
    println("hello");
}

Use instead:

fun main() {
    println("hello");
}

Or prefix with an underscore if the variable is intentionally unused:

fun main() {
    val _x = 1;
    println("hello");
}

Locals prefixed with _ are intentionally ignored.
The rule also skips type parameters, implicit asm/builtin parameters, and self.
Autofix prefixes the declaration identifier with _.

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E001: field-init-can-be-folded

Checks for struct initialization where the field name and the variable used to initialize it are the same.

E003: mutable-variable-can-be-immutable

Checks for variables that are declared as mutable (`var`) but are never mutated.