eslint-plugin-safe-jsx is an ESLint plugin that enforces explicit boolean conversion before using the && operator with JSX in React and React Native applications. This plugin improves the reliability of your code by helping prevent certain types of bugs that can break your app.

In JavaScript, certain "falsy" values such as 0, '', and null can lead to unexpected behavior when used in a logical expression. This can be particularly problematic in React JSX code, where you might be expecting a boolean value.

Consider the following example:

const myText = 0;
myText && <Text>{myText}</Text>;

In this scenario, the code tries to render 0 outside the Text component, leading to a failure. The issue is even more critical when the variable value comes from a server or an external source. This ESLint rule helps prevent such scenarios from occurring.

With eslint-plugin-safe-jsx, ESLint will alert you to these potential errors and can even auto-fix them, like so:

const myText = 0;
Boolean(myText) && <Text>{myText}</Text>;

Now, myText is explicitly converted to a boolean before being used in the logical expression, preventing the 0 from being rendered.

For more examples, check out our test cases.

You'll first need to install ESLint:

# npm
npm install eslint --save-dev

# yarn
yarn add eslint --dev

Next, install eslint-plugin-safe-jsx:

# npm
npm install eslint-plugin-safe-jsx --save-dev

# yarn
yarn add eslint-plugin-safe-jsx --dev

Note: If you installed ESLint globally (using the -g flag in npm, or the global prefix in yarn) then you must also install eslint-plugin-safe-jsx globally.

Add safe-jsx to the plugins section of your .eslintrc configuration file. You can omit the eslint-plugin- prefix:

{
  "plugins": ["safe-jsx"]
}

Then configure the rules you want to use under the rules section.

{
  "rules": {
    "safe-jsx/jsx-explicit-boolean": "error" // or "warn"
  }
}

• jsx-explicit-boolean: Enforces explicit boolean conversion before using the && operator with JSX.

We welcome your contributions! For major changes, please open an issue first to discuss what you would like to change. Don't forget to update tests as appropriate.

MIT