Test the var invariant

A compact payload that references --missing will look fine in development if the host app's sheet happens to declare it, then break in email or SVG. @elastic/distillate/testing scans CSS text and reports var(...) names that are never declared in the same string.

import {
  assertVarRefsHaveDeclarations,
  findVarRefViolations,
} from '@elastic/distillate/testing';

const css = distillery.renderStyles(collector);
assertVarRefsHaveDeclarations(css);
		

1. throws with surrounding context

findVarRefViolations returns { reference, context }[] when the assertion should not throw.

The scanner is whitespace-tolerant (var( --x )) and ignores strings, comments, and function names that merely end in var. A BEM selector like .button--active:hover is not a declaration of --active.

This entry reaches no third-party package. Run it against both compact artifacts and readable stylesheets; the helper does not care which names you used.