literalConstructorWrappers

Prefers literal syntax over constructor function calls for primitive values.

✅ This rule is included in the ts stylistic and stylisticStrict presets.

JavaScript provides built-in constructor functions for creating primitive values: BigInt(), Boolean(), Number(), and String(). While these constructors can coerce values to their respective types, using literal syntax is often more concise and idiomatic when the argument is already a literal value.

This rule flags constructor calls with literal arguments that could be replaced with literal syntax.

Examples

❌ Incorrect

const value = BigInt(123);

const value = Boolean(true);

const value = Number("42");

const value = String(123);

const value = String(true);

✅ Correct

const value = 123n;

const value = true;

const value = 42;

const text = "123";

const text = `${someVariable}`;

const value = BigInt(variable);

const value = Boolean(variable);

Options

This rule is not configurable.

When Not To Use It

If you prefer the explicit constructor syntax for consistency in your codebase, or if you’re maintaining a codebase where constructor calls are used as a deliberate style choice to make type coercion more explicit, you might prefer to disable this rule.

Further Reading

• MDN documentation on BigInt
• MDN documentation on Boolean
• MDN documentation on Number
• MDN documentation on String

Equivalents in Other Linters

• ESLint: unicorn/prefer-bigint-literals