noInvalidBuiltinInstantiation (JavaScript)

Language JavaScript (and super languages)

Summary

Rule available since: v1.7.2
Diagnostic Category: lint/correctness/noInvalidBuiltinInstantiation
This rule is recommended, meaning it is enabled by default.
This rule has an unsafe fix.
The default severity of this rule is error.
Sources:
- Same as unicorn/new-for-builtins
- Same as no-new-native-nonconstructor

How to configure

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{
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  "linter": {
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    "rules": {
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      "correctness": {
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        "noInvalidBuiltinInstantiation": "error"
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      }
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    }
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  }
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}

Description

Ensure that builtins are correctly instantiated.

The following builtins require new to be instantiate:

ArrayBuffer
BigInt64Array
BigUint64Array
DataView
FinalizationRegistry
Float32Array
Float64Array
Int16Array
Int32Array
Int8Array
Map
Promise
Proxy
Set
SharedArrayBuffer
Uint16Array
Uint32Array
Uint8Array
Uint8ClampedArray
WeakMap
WeakRef
WeakSet

Conversely, the following builtins cannot be instantiated with new:

BigInt
Symbol

Examples

Invalid

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const text = new BigInt(1);

code-block.js:1:14 lint/correctness/noInvalidBuiltinInstantiation  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━

  ✖ Use BigInt() instead of new BigInt().
  
  > 1 │ const text = new BigInt(1);
      │              ^^^^^^^^^^^^^
    2 │ 
  
  ℹ Unsafe fix: Remove new keyword.
  
    1 │ const·text·=·new·BigInt(1);
      │              ----

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const map = Map([
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  ['foo', 'bar']
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]);

code-block.js:1:13 lint/correctness/noInvalidBuiltinInstantiation  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━

  ✖ Use new Map() instead of Map().
  
  > 1 │ const map = Map([
      │             ^^^^^
  > 2 │   ['foo', 'bar']
  > 3 │ ]);
      │ ^^
    4 │ 
  
  ℹ Unsafe fix: Add new keyword.
  
    1 │ const·map·=·new·Map([
      │             ++++

Valid

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const text = BigInt(1);

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const map = new Map([
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 ['foo', 'bar']
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]);