stylelint-scss/src/utils/moduleNamespace.js

A collection of SCSS-specific rules for Stylelint

"use strict";

/**
 * Returns the namespace of an imported module or `null` if the namespace is removed.
 *
 * Example: no import found, possibly using global function
 * `@use "sass:color";`
 * `moduleNamespace(root, 'sass:map')` returns 'map'
 *
 * Example: default namespace
 * `@use "sass:map";`
 * `moduleNamespace(root, 'sass:map')` returns `map`
 *
 * Example: custom namespace
 * `@use "sass:map" as ns;`
 * `moduleNamespace(root, 'sass:map')` returns 'ns'
 *
 * Example: no namespace
 * `@use "sass:map" as *;`
 * `moduleNamespace(root, 'sass:map')` returns `null`
 *
 * Have a look at the tests for more examples.
 */
module.exports = function moduleNamespace(root, module) {
  let moduleNamespace = getDefaultNamespace(module);

  root.walkAtRules("use", rule => {
    const customNamespace = getCustomNamespace(module, rule);

    switch (customNamespace) {
      case null:
        return;
      case "*":
        moduleNamespace = null;
        return;
      default:
        moduleNamespace = customNamespace;
    }
  });

  return moduleNamespace;
};

function getDefaultNamespace(module) {
  return module.match(/([^/:]+)$/)[1].replace(/\.[^.]+$/, "");
}

function getCustomNamespace(module, rule) {
  const ruleParamsParts = rule.params.split(
    new RegExp(`["']${module}['"][ \n]*as`)
  );

  if (ruleParamsParts.length < 2) {
    return null;
  }

  const secondRuleParamsPart = ruleParamsParts[1].trim();

  return !secondRuleParamsPart.startsWith("*")
    ? secondRuleParamsPart.split(" ")[0]
    : "*";
}