Rework hook error tests to actually assert

test/integration/helpers.js

@@ -1,5 +1,6 @@
 var spawn = require('child_process').spawn;
 var path  = require('path');
+var fs = require('fs');
 
 module.exports = {
   /**
@@ -35,6 +36,47 @@ module.exports = {
     });
   },
 
+  /**
+   * Invokes the mocha binary on the code of the body of the function.
+   * Accepts an array of additional command line args to pass. The callback is
+   * invoked with a summary of the run, in addition to its output. The summary
+   * includes the number of passing, pending, and failing tests, as well as the
+   * exit code. Useful for testing different reporters.
+   *
+   * Example response:
+   * {
+   *   pending: 0,
+   *   passing: 0,
+   *   failing: 1,
+   *   code:    1,
+   *   output:  '...'
+   * }
+   *
+   * @param {function} fixture
+   * @param {array}    args
+   * @param {function} fn
+   */
+  runMochaFunction: function(fixture, args, fn) {
+    var path = resolveFixturePath(fixture.name + '.js' || 'tempfile.js');
+    args = args || [];
+
+    var fixtureContent = 'var fn = ' + fixture.toString() + '; fn()';
+    fs.writeFileSync(path, fixtureContent, 'utf8');
+
+    function cleanup() {
+      fs.unlink(path);
+      fn.apply(this, arguments);
+    }
+
+    invokeMocha(args.concat(['-C', path]), function(err, res) {
+      if (err) {
+        return cleanup(err);
+      }
+
+      cleanup(null, getSummary(res));
+    });
+  },
+
   /**
    * Invokes the mocha binary for the given fixture using the JSON reporter,
    * returning the parsed output, as well as exit code.