Unexpected block statement surrounding arrow body

The block statement isn't needed for a single expression.

this.state.todos.filter(filterTodo => filterTodo !== todo);

To add on Kevin answer, the error is related to your eslint configuration. This said, if arrow-body-style option is set to true, OP is correct. An other example would be something like this :

    return this.state.greetings.map((name) => {
        return <HelloWorld key={name} name={name} />;
    });

Without arrow-body-style option, block statement ( { return ...} ) is not needed as per Kevin answer.

This actually open a new question as to which style is more appropriate.

For further references : http://eslint.org/docs/rules/arrow-body-style

If you really don't want to wrap arrow function inside block statement then you can turn off.

module.exports = {
  extends: "airbnb-base",
  rules: {
    "arrow-body-style": 0
  },
  "env": {
    "jest": true
  }
};