Allow to retry failed test from test context for mochajs#1773

lib/context.js

@@ -76,6 +76,21 @@ Context.prototype.skip = function() {
   return this;
 };
 
+/**
+ * Allow a number of retires on failed tests
+ *
+ * @api private
+ * @param {number} n
+ * @return {Context} self
+ */
+Context.prototype.retries = function(n) {
+  if (!arguments.length) {
+    return this.runnable().retries();
+  }
+  this.runnable().retries(n);
+  return this;
+};
+
 /**
  * Inspect the context void of `._runnable`.
  *

lib/interfaces/bdd.js

@@ -106,5 +106,12 @@ module.exports = function(suite) {
     context.xit = context.xspecify = context.it.skip = function(title) {
       context.it(title);
     };
+
+    /**
+     * Number of attempts to retry.
+     */
+    context.it.retries = function(n) {
+      context.retries(n);
+    };
   });
 };

lib/interfaces/common.js

@@ -70,6 +70,15 @@ module.exports = function(suites, context) {
        */
       skip: function(title) {
         context.test(title);
+      },
+
+      /**
+       * Number of retry attempts
+       *
+       * @param {string} n
+       */
+      retries: function(n) {
+        context.retries(n);
       }
     }
   };

lib/interfaces/qunit.js

@@ -89,5 +89,6 @@ module.exports = function(suite) {
     };
 
     context.test.skip = common.test.skip;
+    context.test.retries = common.test.retries;
   });
 };

lib/interfaces/tdd.js

@@ -101,5 +101,6 @@ module.exports = function(suite) {
     };
 
     context.test.skip = common.test.skip;
+    context.test.retries = common.test.retries;
   });
 };

lib/runnable.js

@@ -52,6 +52,7 @@ function Runnable(title, fn) {
   this._enableTimeouts = true;
   this.timedOut = false;
   this._trace = new Error('done() called multiple times');
+  this._retries = -1;
 }
 
 /**
@@ -128,6 +129,20 @@ Runnable.prototype.skip = function() {
   throw new Pending();
 };
 
+/**
+ * Set number of retires.
+ *
+ * @api private
+ */
+Runnable.prototype.retries = function(n) {
+  if (!arguments.length) {
+    return this._retries;
+  }
+  if (this._retries === -1){
+    this._retries = n;
+  }
+};
+
 /**
  * Return the full title generated by recursively concatenating the parent's
  * full title.
@@ -230,6 +245,10 @@ Runnable.prototype.run = function(fn) {
 
   // finished
   function done(err) {
+    if (err&&self._retries) {
+      self._retries--;
+      return self.run(fn);
+    }
     var ms = self.timeout();
     if (self.timedOut) {
       return;

test/runnable.js

@@ -89,6 +89,14 @@ describe('Runnable(title, fn)', function(){
     })
   })
 
+  describe('#retries(n)', function(){
+    it('should set the number of retries', function(){
+      var run = new Runnable;
+      run.retries(1);
+      run.retries().should.equal(1);
+    })
+  })
+
   describe('.run(fn)', function(){
     describe('when .pending', function(){
       it('should not invoke the callback', function(done){
@@ -101,6 +109,21 @@ describe('Runnable(title, fn)', function(){
       })
     })
 
+    describe('when ._retries', function(){
+      it('should retry until out of retries', function(done){
+        var test = new Runnable('foo', function(){
+          throw new Error('should invoke the callback');
+        });
+
+        test.retries(2);
+        test.run(function(err){
+          test.retries().should.equal(0);
+          err.message.should.equal('should invoke the callback');
+          done();
+        })
+      })
+    })
+
     describe('when sync', function(){
       describe('without error', function(){
         it('should invoke the callback', function(done){