logical-assignment-operators

options = options || {} names the variable twice, and it assigns even when options keeps its value. options ||= {} says the same thing with one name and only assigns when it needs to.

--fix rewrites the code when the target is a plain variable. A property can have a getter or a setter, and the rewrite can change how often they run, so user.name = user.name || "guest" gets a suggestion instead of a fix.

Configure

Off by default. To turn it on:

[lint.rules]
"logical-assignment-operators" = "error" # or "warn"

Every option, set to its default:

[lint.rules]
"logical-assignment-operators" = [
  "error",
  "always", # "always" or "never"
  {
    enforceForIfStatements = false,
  },
]

Examples

Reported:

options = options || {};
cache = cache ?? new Map();
enabled = enabled && isReady();
title || (title = "Untitled");
user.name = user.name || "guest";

Not reported:

options ||= {};
cache ??= new Map();
enabled &&= isReady();
title ||= "Untitled";
user.name ||= "guest";

Options

[lint.rules]
logical-assignment-operators = ["error", "always", {
  enforceForIfStatements = true,
}]

Option	What it does
"always" (default)	Report code that could use a logical assignment operator.
"never"	Report every logical assignment operator.

Option	Default	What it does
enforceForIfStatements	false	With "always", also report an if that only assigns to the value it tests.

options ||= {};

options = options || {};

enforceForIfStatements

if (!title) {
  title = "Untitled";
}

if (cache == null) cache = new Map();

if (!title) {
  title = "Untitled";
}

if (cache == null) cache = new Map();