patch 7.4.944
Problem:    Writing tests for Vim script is hard.
Solution:   Add assertEqual(), assertFalse() and assertTrue() functions.  Add
            the v:errors variable.  Add the runtest script. Add a first new
            style test script.
diff --git a/src/testdir/test_assert.vim b/src/testdir/test_assert.vim
new file mode 100644
index 0000000..61c77c5
--- /dev/null
+++ b/src/testdir/test_assert.vim
@@ -0,0 +1,19 @@
+" Test that the methods used for testing work.
+
+func Test_assertFalse()
+  call assertFalse(0)
+endfunc
+
+func Test_assertTrue()
+  call assertTrue(1)
+  call assertTrue(123)
+endfunc
+
+func Test_assertEqual()
+  let s = 'foo'
+  call assertEqual('foo', s)
+  let n = 4
+  call assertEqual(4, n)
+  let l = [1, 2, 3]
+  call assertEqual([1, 2, 3], l)
+endfunc