---
source: crates/biome_js_analyze/tests/spec_tests.rs
expression: invalid.ts
---
# Input
```ts
interface I {
  new (): I;
}

interface I {
	constructor(): void;
}

// Works for generic type.
interface G {
  new (): G<T>;
}

type T = {
  constructor(): void;
};

class C {
  new(): C;
}

class C {
  new(): this;
}

declare abstract class C {
  new(): C;
}

interface I {
  constructor(): '';
}

interface I {
  new(): this;
}

```

# Diagnostics
```
invalid.ts:2:3 lint/suspicious/noMisleadingInstantiator ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ! Don't use the new method in interfaces.
  
    1 │ interface I {
  > 2 │   new (): I;
      │   ^^^^^^^^^^
    3 │ }
    4 │ 
  
  i new in an interface suggests it's instantiable, which is incorrect. The returned type should different from the constructor's type.
  

```

```
invalid.ts:6:2 lint/suspicious/noMisleadingInstantiator ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ! Don't use the constructor method in interfaces.
  
    5 │ interface I {
  > 6 │ 	constructor(): void;
      │ 	^^^^^^^^^^^^^^^^^^^^
    7 │ }
    8 │ 
  
  i Interfaces define a contract, not an implementation. Thus, including a constructoris not appropriate.
  

```

```
invalid.ts:11:3 lint/suspicious/noMisleadingInstantiator ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ! Don't use the new method in interfaces.
  
     9 │ // Works for generic type.
    10 │ interface G {
  > 11 │   new (): G<T>;
       │   ^^^^^^^^^^^^^
    12 │ }
    13 │ 
  
  i new in an interface suggests it's instantiable, which is incorrect. The returned type should different from the constructor's type.
  

```

```
invalid.ts:15:3 lint/suspicious/noMisleadingInstantiator ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ! Don't use the constructor method in type aliases.
  
    14 │ type T = {
  > 15 │   constructor(): void;
       │   ^^^^^^^^^^^^^^^^^^^^
    16 │ };
    17 │ 
  
  i Type aliases simply rename types. They don't execute code, so a constructoris misleading.
  

```

```
invalid.ts:19:3 lint/suspicious/noMisleadingInstantiator ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ! Don't use the new method in classes.
  
    18 │ class C {
  > 19 │   new(): C;
       │   ^^^^^^^^^
    20 │ }
    21 │ 
  
  i new is typically used to instantiate objects. In classes, its usage can be misleading.
  

```

```
invalid.ts:23:3 lint/suspicious/noMisleadingInstantiator ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ! Don't use the new method in classes.
  
    22 │ class C {
  > 23 │   new(): this;
       │   ^^^^^^^^^^^^
    24 │ }
    25 │ 
  
  i new is typically used to instantiate objects. In classes, its usage can be misleading.
  

```

```
invalid.ts:27:3 lint/suspicious/noMisleadingInstantiator ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ! Don't use the new method in classes.
  
    26 │ declare abstract class C {
  > 27 │   new(): C;
       │   ^^^^^^^^^
    28 │ }
    29 │ 
  
  i new is typically used to instantiate objects. In classes, its usage can be misleading.
  

```

```
invalid.ts:27:3 lint/suspicious/noMisleadingInstantiator ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ! Don't use the new method in classes.
  
    26 │ declare abstract class C {
  > 27 │   new(): C;
       │   ^^^^^^^^^
    28 │ }
    29 │ 
  
  i new is typically used to instantiate objects. In classes, its usage can be misleading.
  

```

```
invalid.ts:31:3 lint/suspicious/noMisleadingInstantiator ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ! Don't use the constructor method in interfaces.
  
    30 │ interface I {
  > 31 │   constructor(): '';
       │   ^^^^^^^^^^^^^^^^^^
    32 │ }
    33 │ 
  
  i Interfaces define a contract, not an implementation. Thus, including a constructoris not appropriate.
  

```

```
invalid.ts:35:3 lint/suspicious/noMisleadingInstantiator ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ! Don't use the new method in interfaces.
  
    34 │ interface I {
  > 35 │   new(): this;
       │   ^^^^^^^^^^^^
    36 │ }
    37 │ 
  
  i new in an interface suggests it's instantiable, which is incorrect. The returned type should different from the constructor's type.
  

```