---
source: crates/biome_js_analyze/tests/spec_tests.rs
expression: invalidScript.jsonc
---
# Input
```cjs
var x = 1; foo(x);
```

# Diagnostics
```
invalidScript.jsonc:1:1 lint/style/noVar  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ! Use let or const instead of var.
  
  > 1 │ var x = 1; foo(x);
      │ ^^^^^^^^^
  
  i A variable declared with var in the global scope pollutes the global object.
  
  i See MDN web docs for more details.
  
  i Unsafe fix: Use 'const' instead.
  
  - var·x·=·1;·foo(x);
  + const·x·=·1;·foo(x);
  

```

# Input
```cjs
var x = 1; x = 5;
```

# Diagnostics
```
invalidScript.jsonc:1:1 lint/style/noVar  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ! Use let or const instead of var.
  
  > 1 │ var x = 1; x = 5;
      │ ^^^^^^^^^
  
  i A variable declared with var in the global scope pollutes the global object.
  
  i See MDN web docs for more details.
  
  i Unsafe fix: Use 'let' instead.
  
  - var·x·=·1;·x·=·5;
  + let·x·=·1;·x·=·5;
  

```

# Input
```cjs
for (var i in [1,2,3]) { foo(i); }
```

# Diagnostics
```
invalidScript.jsonc:1:6 lint/style/noVar  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ! Use let or const instead of var.
  
  > 1 │ for (var i in [1,2,3]) { foo(i); }
      │      ^^^^^
  
  i A variable declared with var in the global scope pollutes the global object.
  
  i See MDN web docs for more details.
  
  i Unsafe fix: Use 'const' instead.
  
  - for·(var·i·in·[1,2,3])·{·foo(i);·}
  + for·(const·i·in·[1,2,3])·{·foo(i);·}
  

```

# Input
```cjs
for (var x of [1,2,3]) { foo(x); }
```

# Diagnostics
```
invalidScript.jsonc:1:6 lint/style/noVar  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ! Use let or const instead of var.
  
  > 1 │ for (var x of [1,2,3]) { foo(x); }
      │      ^^^^^
  
  i A variable declared with var in the global scope pollutes the global object.
  
  i See MDN web docs for more details.
  
  i Unsafe fix: Use 'const' instead.
  
  - for·(var·x·of·[1,2,3])·{·foo(x);·}
  + for·(const·x·of·[1,2,3])·{·foo(x);·}
  

```

# Input
```cjs
var [x = -1, y] = [1,2]; y = 0;
```

# Diagnostics
```
invalidScript.jsonc:1:1 lint/style/noVar  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ! Use let or const instead of var.
  
  > 1 │ var [x = -1, y] = [1,2]; y = 0;
      │ ^^^^^^^^^^^^^^^^^^^^^^^
  
  i A variable declared with var in the global scope pollutes the global object.
  
  i See MDN web docs for more details.
  
  i Unsafe fix: Use 'let' instead.
  
  - var·[x·=·-1,·y]·=·[1,2];·y·=·0;
  + let·[x·=·-1,·y]·=·[1,2];·y·=·0;
  

```

# Input
```cjs
var {a: x = -1, b: y} = {a:1,b:2}; y = 0;
```

# Diagnostics
```
invalidScript.jsonc:1:1 lint/style/noVar  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ! Use let or const instead of var.
  
  > 1 │ var {a: x = -1, b: y} = {a:1,b:2}; y = 0;
      │ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  
  i A variable declared with var in the global scope pollutes the global object.
  
  i See MDN web docs for more details.
  
  i Unsafe fix: Use 'let' instead.
  
  - var·{a:·x·=·-1,·b:·y}·=·{a:1,b:2};·y·=·0;
  + let·{a:·x·=·-1,·b:·y}·=·{a:1,b:2};·y·=·0;
  

```