feat(testrunner): ability to repeat test suites (#681)

Now you can `fdescribe.repeat(10)` to repeat test suites.

Author: aslushnikov

utils/testrunner/TestRunner.js

@@ -322,20 +322,30 @@ class TestRunner extends EventEmitter {
       }
     }
 
+    const duplicateTest = (amount, mode, timeout) => {
+      return (name, callback) => {
+        for (let i = 0; i < amount; ++i)
+          this._addTest(name, callback, mode, timeout);
+      }
+    }
+
+    const duplicateSuite = (amount, mode) => {
+      return (name, callback, ...args) => {
+        for (let i = 0; i < amount; ++i)
+          this._addSuite(mode, name, callback, ...args);
+      }
+    }
+
     // bind methods so that they can be used as a DSL.
     this.describe = this._addSuite.bind(this, TestMode.Run);
     this.describe.skip = condition => condition ? this.xdescribe : this.describe;
+    this.describe.repeat = number => duplicateSuite(number, TestMode.Run);
     this.fdescribe = this._addSuite.bind(this, TestMode.Focus);
     this.fdescribe.skip = () => this.fdescribe; // no-op
+    this.fdescribe.repeat = number => duplicateSuite(number, TestMode.Focus);
     this.xdescribe = this._addSuite.bind(this, TestMode.Skip);
     this.xdescribe.skip = () => this.xdescribe; // no-op
-
-    const duplicateTest = (amount, mode, timeout) => {
-      return (name, callback) => {
-        for (let i = 0; i < amount; ++i)
-          this._addTest(name, callback, mode, timeout);
-      }
-    }
+    this.xdescribe.repeat = number => duplicateSuite(number, TestMode.Skip);
 
     this.it = (name, callback) => void this._addTest(name, callback, TestMode.Run, this._timeout);
     this.it.skip = condition => condition ? this.xit : this.it;