---
source: crates/biome_js_analyze/tests/spec_tests.rs
expression: invalid.jsx
---
# Input
```jsx
let a = <button
    className="SomeManyClasses"
    onClick={(event) => console.log(event.ctrlKey == true)}
    style="color: red"
>
    Some content
</button>;
```

# Diagnostics
```
invalid.jsx:3:51 lint/suspicious/noDoubleEquals  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ! Use === instead of ==
  
    1 │ let a = <button
    2 │     className="SomeManyClasses"
  > 3 │     onClick={(event) => console.log(event.ctrlKey == true)}
      │                                                   ^^
    4 │     style="color: red"
    5 │ >
  
  i == is only allowed when comparing against null
  
    1 │ let a = <button
    2 │     className="SomeManyClasses"
  > 3 │     onClick={(event) => console.log(event.ctrlKey == true)}
      │                                                   ^^
    4 │     style="color: red"
    5 │ >
  
  i Using == may be unsafe if you are relying on type coercion
  
  i Unsafe fix: Use ===
  
    3 │ ····onClick={(event)·=>·console.log(event.ctrlKey·===·true)}
      │                                                     +       

```