1  var assert = require('assert');
 2  
 3  var mustCallChecks = [];
 4  
 5  function runCallChecks() {
 6    var failed_count = 0;
 7    for (var i=0 ; i< mustCallChecks.length; ++i) {
 8      var context = mustCallChecks[i];
 9      if (context.actual === context.expected) {
10        continue;
11      }
12  
13      failed_count++;
14      console.log('Mismatched %s function calls. Expected %d, actual %d.',
15                  context.name,
16                  context.expected,
17                  context.actual);
18      console.log(context.stack.split('\n').slice(2).join('\n'));
19    }
20  
21    assert(failed_count === 0);
22  }
23  
24  after(runCallChecks);
25  
26  exports.mustCall = function(fn, expected) {
27    if (typeof expected !== 'number') expected = 1;
28  
29    var context = {
30      expected: expected,
31      actual: 0,
32      stack: (new Error).stack,
33      name: fn.name || '<anonymous>'
34    };
35  
36    mustCallChecks.push(context);
37  
38    return function() {
39      context.actual++;
40      return fn.apply(this, arguments);
41    };
42  };