Disallow template literal placeholder syntax in regular strings (no-template-curly-in-string)

ECMAScript 6 allows programmers to create strings containing variable or expressions using template literals, instead of string concatenation, by writing expressions like ${variable} between two backtick quotes (`). It can be easy to use the wrong quotes when wanting to use template literals, by writing "${variable}", and end up with the literal value "${variable}" instead of a string containing the value of the injected expressions.

Rule Details

This rule aims to warn when a regular string contains what looks like a template literal placeholder. It will warn when it finds a string containing the template literal placeholder (${something}) that uses either " or ' for the quotes.

Examples

Examples of incorrect code for this rule:

/*eslint no-template-curly-in-string: "error"*/
"Hello ${name}!";
'Hello ${name}!';
"Time: ${12 * 60 * 60 * 1000}";

Examples of correct code for this rule:

/*eslint no-template-curly-in-string: "error"*/
`Hello ${name}!`;
`Time: ${12 * 60 * 60 * 1000}`;

templateFunction`Hello ${name}`;

When Not To Use It

This rule should not be used in ES3/5 environments.

Version

This rule was introduced in ESLint 3.3.0.

Resources

• Rule source
• Documentation source