complete/no-unnecessary-assignment

💼 This rule is enabled in the ✅ recommended config.

📝 Disallows useless assignments.

💭 This rule requires type information.

Rule Details

Sometimes, refactoring can lead to assignment statements that were once useful but are now redundant. This rule helps you clean up the dead code in a similar way that the @typescript-eslint/no-unnecessary-condition rule does.

// Bad
declare let foo: 1;
declare let bar: 1;
foo = bar;

// Bad
declare let foo: number;
foo += 0;

// Bad
declare let foo: string;
foo += "";

// Bad
declare const foo: boolean;
const bar = foo || false;
const baz = foo && true;

// Bad
declare const foo: number;
const bar = foo || 0;

// Bad
declare const foo: string;
const bar = foo || "";

// Bad
declare const foo: string | null;
const bar = foo ?? null;

// Bad
declare const foo: string | undefined;
const bar = foo ?? undefined;

Note that while “<<” is technically a useless operator when combined with 0, this rule will not report on it so that bit flag enums will not cause false positives.

Options

This rule is not configurable.

Resources

• How to use this rule
• Rule source
• Test source