It's possible to create multiline strings in JavaScript by using a slash before a newline, such as:

var x = "Line 1 \
         Line 2";

Some consider this to be a bad practice as it was an undocumented feature of JavaScript that was only formalized later.

Rule Details

This rule is aimed at preventing the use of multiline strings.

Examples of incorrect code for this rule:

::: incorrect

/*eslint no-multi-str: "error"*/

var x = "some very \
long text";

:::

Examples of correct code for this rule:

::: correct

/*eslint no-multi-str: "error"*/

var x = "some very long text";

var x = "some very " +
        "long text";

:::