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syntax-string-no-invalid

Disallow invalid syntax strings.

@property --foo {
  syntax: "<color>";
/**       ↑
 * Syntax strings like this */
}

Use this rule to avoid custom properties that never register. An invalid syntax string invalidates the whole @property rule.

Syntax strings are used for the syntax descriptor value of the @property at-rule. This rule reports invalid syntax strings and unsupported type names.

You can check §5.1 “Supported Names” of the CSS Properties & Values API for a list of valid syntax component names.

This rule supports 1 message argument: the invalid syntax string.

Options​

true​

{
  "syntax-string-no-invalid": true
}

The following patterns are considered problems:

@property --foo {
  syntax: "<bar>";
}
@property --foo {
  syntax: "<alpha-value>";
}

The following patterns are not considered problems:

@property --foo {
  syntax: "<color>";
}
@property --foo {
  syntax: "<length> | <color>";
}