---
source: crates/biome_js_analyze/tests/spec_tests.rs
expression: invalid.ts
---
# Input
```ts
switch (1) {
	case 1:
		enum E {}
		break;
}

switch (1) {
	default:
		enum E {}
		break;
}

switch (1) {
	case 1:
		interface I {}
		break;
}

switch (1) {
	default:
		interface I {}
		{
		}
		break;
}

switch (1) {
	case 1:
		type N = number;
		break;
}

switch (1) {
	default:
		type N = number;
		break;
}

```

# Diagnostics
```
invalid.ts:3:3 lint/correctness/noSwitchDeclarations  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ! Other switch clauses can erroneously access this declaration.
    Wrap the declaration in a block to restrict its access to the switch clause.
  
    1 │ switch (1) {
    2 │ 	case 1:
  > 3 │ 		enum E {}
      │ 		^^^^^^^^^
    4 │ 		break;
    5 │ }
  
  i The declaration is defined in this switch clause:
  
    1 │ switch (1) {
  > 2 │ 	case 1:
      │ 	^^^^^^^
  > 3 │ 		enum E {}
  > 4 │ 		break;
      │ 		^^^^^^
    5 │ }
    6 │ 
  
  i Unsafe fix: Wrap the declaration in a block.
  
     1  1 │   switch (1) {
     2    │ - → case·1:
        2 │ + → case·1:·{
     3  3 │   		enum E {}
     4  4 │   		break;
        5 │ + → }
     5  6 │   }
     6  7 │   
  

```

```
invalid.ts:9:3 lint/correctness/noSwitchDeclarations  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ! Other switch clauses can erroneously access this declaration.
    Wrap the declaration in a block to restrict its access to the switch clause.
  
     7 │ switch (1) {
     8 │ 	default:
   > 9 │ 		enum E {}
       │ 		^^^^^^^^^
    10 │ 		break;
    11 │ }
  
  i The declaration is defined in this switch clause:
  
     7 │ switch (1) {
   > 8 │ 	default:
       │ 	^^^^^^^^
   > 9 │ 		enum E {}
  > 10 │ 		break;
       │ 		^^^^^^
    11 │ }
    12 │ 
  
  i Unsafe fix: Wrap the declaration in a block.
  
     6  6 │   
     7  7 │   switch (1) {
     8    │ - → default:
        8 │ + → default:·{
     9  9 │   		enum E {}
    10 10 │   		break;
       11 │ + → }
    11 12 │   }
    12 13 │   
  

```

```
invalid.ts:15:3 lint/correctness/noSwitchDeclarations  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ! Other switch clauses can erroneously access this declaration.
    Wrap the declaration in a block to restrict its access to the switch clause.
  
    13 │ switch (1) {
    14 │ 	case 1:
  > 15 │ 		interface I {}
       │ 		^^^^^^^^^^^^^^
    16 │ 		break;
    17 │ }
  
  i The declaration is defined in this switch clause:
  
    13 │ switch (1) {
  > 14 │ 	case 1:
       │ 	^^^^^^^
  > 15 │ 		interface I {}
  > 16 │ 		break;
       │ 		^^^^^^
    17 │ }
    18 │ 
  
  i Unsafe fix: Wrap the declaration in a block.
  
    12 12 │   
    13 13 │   switch (1) {
    14    │ - → case·1:
       14 │ + → case·1:·{
    15 15 │   		interface I {}
    16 16 │   		break;
       17 │ + → }
    17 18 │   }
    18 19 │   
  

```

```
invalid.ts:21:3 lint/correctness/noSwitchDeclarations  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ! Other switch clauses can erroneously access this declaration.
    Wrap the declaration in a block to restrict its access to the switch clause.
  
    19 │ switch (1) {
    20 │ 	default:
  > 21 │ 		interface I {}
       │ 		^^^^^^^^^^^^^^
    22 │ 		{
    23 │ 		}
  
  i The declaration is defined in this switch clause:
  
    19 │ switch (1) {
  > 20 │ 	default:
       │ 	^^^^^^^^
  > 21 │ 		interface I {}
  > 22 │ 		{
  > 23 │ 		}
  > 24 │ 		break;
       │ 		^^^^^^
    25 │ }
    26 │ 
  
  i Unsafe fix: Wrap the declaration in a block.
  
    18 18 │   
    19 19 │   switch (1) {
    20    │ - → default:
       20 │ + → default:·{
    21 21 │   		interface I {}
    22 22 │   		{
    23 23 │   		}
    24 24 │   		break;
       25 │ + → }
    25 26 │   }
    26 27 │   
  

```

```
invalid.ts:29:3 lint/correctness/noSwitchDeclarations  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ! Other switch clauses can erroneously access this declaration.
    Wrap the declaration in a block to restrict its access to the switch clause.
  
    27 │ switch (1) {
    28 │ 	case 1:
  > 29 │ 		type N = number;
       │ 		^^^^^^^^^^^^^^^^
    30 │ 		break;
    31 │ }
  
  i The declaration is defined in this switch clause:
  
    27 │ switch (1) {
  > 28 │ 	case 1:
       │ 	^^^^^^^
  > 29 │ 		type N = number;
  > 30 │ 		break;
       │ 		^^^^^^
    31 │ }
    32 │ 
  
  i Unsafe fix: Wrap the declaration in a block.
  
    26 26 │   
    27 27 │   switch (1) {
    28    │ - → case·1:
       28 │ + → case·1:·{
    29 29 │   		type N = number;
    30 30 │   		break;
       31 │ + → }
    31 32 │   }
    32 33 │   
  

```

```
invalid.ts:35:3 lint/correctness/noSwitchDeclarations  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ! Other switch clauses can erroneously access this declaration.
    Wrap the declaration in a block to restrict its access to the switch clause.
  
    33 │ switch (1) {
    34 │ 	default:
  > 35 │ 		type N = number;
       │ 		^^^^^^^^^^^^^^^^
    36 │ 		break;
    37 │ }
  
  i The declaration is defined in this switch clause:
  
    33 │ switch (1) {
  > 34 │ 	default:
       │ 	^^^^^^^^
  > 35 │ 		type N = number;
  > 36 │ 		break;
       │ 		^^^^^^
    37 │ }
    38 │ 
  
  i Unsafe fix: Wrap the declaration in a block.
  
    32 32 │   
    33 33 │   switch (1) {
    34    │ - → default:
       34 │ + → default:·{
    35 35 │   		type N = number;
    36 36 │   		break;
       37 │ + → }
    37 38 │   }
    38 39 │   
  

```