1  module.exports = { selectorMatchesAnyScope, matcherForSelector };
 2  
 3  const { isSubset } = require('underscore-plus');
 4  
 5  // Private: Parse a selector into parts.
 6  //          If already parsed, returns the selector unmodified.
 7  //
 8  // * `selector` a {String|Array<String>} specifying what to match
 9  // Returns selector parts, an {Array<String>}.
10  function parse(selector) {
11    return typeof selector === 'string'
12      ? selector.replace(/^\./, '').split('.')
13      : selector;
14  }
15  
16  const always = scope => true;
17  
18  // Essential: Return a matcher function for a selector.
19  //
20  // * selector, a {String} selector
21  // Returns {(scope: String) -> Boolean}, a matcher function returning
22  // true iff the scope matches the selector.
23  function matcherForSelector(selector) {
24    const parts = parse(selector);
25    if (typeof parts === 'function') return parts;
26    return selector ? scope => isSubset(parts, parse(scope)) : always;
27  }
28  
29  // Essential: Return true iff the selector matches any provided scope.
30  //
31  // * {String} selector
32  // * {Array<String>} scopes
33  // Returns {Boolean} true if any scope matches the selector.
34  function selectorMatchesAnyScope(selector, scopes) {
35    return !selector || scopes.some(matcherForSelector(selector));
36  }