unicorn/max-nested-calls

Nested calls run from the inside out, so you read save(normalize(parse(read(file)))) backwards, counting parentheses on the way. Past a few levels, the code is easier to follow if you put a step in the middle into a well-named variable.

A call counts as nested when it's in an argument of another call or of a new expression. By default up to 3 levels are allowed, and each deeper call is reported.

Configure

Off by default. To turn it on:

[lint.rules]
"unicorn/max-nested-calls" = "error" # or "warn"

Every option, set to its default:

[lint.rules]
"unicorn/max-nested-calls" = ["error", {
  max = 3,
}]

Examples

Reported:

save(normalize(parse(read(file))));

Not reported:

const config = parse(read(file));
save(normalize(config));

A method chain isn't nesting:

const total = text.trim().split(",").map(Number).filter(Boolean).reduce(add);

The count starts again inside a function, a class or JSX:

schedule(retry(withTimeout(() => save(normalize(config)))));

Options

Option	Default	What it does
max	3	The deepest nesting that's allowed.

save(normalize(parse(text)));

save(normalize(parse(read(file))));