From 546473622f41daa1ac45144506b51e66140444b8 Mon Sep 17 00:00:00 2001
From: Alejandro Henkel <henkel@itesm.mx>
Date: Sun, 26 Feb 2017 00:47:10 -0600
Subject: [PATCH] Fix: Validate series/parallel arguments aren't empty or
 invalid (fixes #72) (#75)

---
 lib/helpers/normalizeArgs.js |  5 +++-
 test/parallel.js             | 45 ++++++++++++++++++++++++++++++++++++
 test/series.js               | 45 ++++++++++++++++++++++++++++++++++++
 3 files changed, 94 insertions(+), 1 deletion(-)

diff --git a/lib/helpers/normalizeArgs.js b/lib/helpers/normalizeArgs.js
index 6e5daa5..297601f 100644
--- a/lib/helpers/normalizeArgs.js
+++ b/lib/helpers/normalizeArgs.js
@@ -16,7 +16,10 @@ function normalizeArgs(registry, args) {
     return fn;
   }
 
-  return map(flatten(args), getFunction);
+  var flattenArgs = flatten(args);
+  assert(flattenArgs.length, 'One or more tasks should be combined using series or parallel');
+
+  return map(flattenArgs, getFunction);
 }
 
 module.exports = normalizeArgs;
diff --git a/test/parallel.js b/test/parallel.js
index 90ed186..c07edd7 100644
--- a/test/parallel.js
+++ b/test/parallel.js
@@ -34,6 +34,51 @@ describe('parallel', function() {
     done();
   });
 
+  it('should throw on non-valid tasks combined with valid tasks', function(done) {
+    function fail() {
+      taker.parallel('test1', 'test2', 'test3', {});
+    }
+
+    expect(fail).toThrow(/Task never defined:/);
+    done();
+  });
+
+  it('should throw on tasks array with both valid and non-valid tasks', function(done) {
+    function fail() {
+      taker.parallel(['test1', 'test2', 'test3', {}]);
+    }
+
+    expect(fail).toThrow(/Task never defined:/);
+    done();
+  });
+
+  it('should throw on non-valid task', function(done) {
+    function fail() {
+      taker.parallel({});
+    }
+
+    expect(fail).toThrow(/Task never defined:/);
+    done();
+  });
+
+  it('should throw when no tasks specified', function(done) {
+    function fail() {
+      taker.parallel();
+    }
+
+    expect(fail).toThrow(/One or more tasks should be combined using series or parallel/);
+    done();
+  });
+
+  it('should throw on empty array of registered tasks', function(done) {
+    function fail() {
+      taker.parallel([]);
+    }
+
+    expect(fail).toThrow(/One or more tasks should be combined using series or parallel/);
+    done();
+  });
+
   it('should take only one array of registered tasks', function(done) {
     taker.parallel(['test1', 'test2', 'test3'])(function(err, results) {
       expect(results).toEqual([1, 2, 3]);
diff --git a/test/series.js b/test/series.js
index 8fdf083..bb071ba 100644
--- a/test/series.js
+++ b/test/series.js
@@ -34,6 +34,51 @@ describe('series', function() {
     done();
   });
 
+  it('should throw on non-valid tasks combined with valid tasks', function(done) {
+    function fail() {
+      taker.series('test1', 'test2', 'test3', {});
+    }
+
+    expect(fail).toThrow(/Task never defined:/);
+    done();
+  });
+
+  it('should throw on tasks array with both valid and non-valid tasks', function(done) {
+    function fail() {
+      taker.series(['test1', 'test2', 'test3', {}]);
+    }
+
+    expect(fail).toThrow(/Task never defined:/);
+    done();
+  });
+
+  it('should throw on non-valid task', function(done) {
+    function fail() {
+      taker.series({});
+    }
+
+    expect(fail).toThrow(/Task never defined:/);
+    done();
+  });
+
+  it('should throw when no tasks specified', function(done) {
+    function fail() {
+      taker.series();
+    }
+
+    expect(fail).toThrow(/One or more tasks should be combined using series or parallel/);
+    done();
+  });
+
+  it('should throw on empty array of registered tasks', function(done) {
+    function fail() {
+      taker.series([]);
+    }
+
+    expect(fail).toThrow(/One or more tasks should be combined using series or parallel/);
+    done();
+  });
+
   it('should take only one array of registered tasks', function(done) {
     taker.series(['test1', 'test2', 'test3'])(function(err, results) {
       expect(results).toEqual([1, 2, 3]);