panic when passing context AND nil in a table Entry

[nunnatsa]

On DescribeTable when adding a context parameter, and a pointer parameter, if the parameter is nil, the test exit with panic.

This example reproduces the issue (note: this is the simplest reproduction I found. This is why the context is not in use; but this is happening also if the context is in use).

func f(num *int) string {
	if num == nil {
		return ""
	}
	return strconv.Itoa(*num)
}

var _ = Describe("some text", func() {
	DescribeTable("table with ctx", func(ctx context.Context, num *int, s string) {
		Expect(f(num)).To(Equal(s))
	},
		Entry("nil", nil, ""),
		Entry("4", &four, "4"),
		Entry("5", &five, "5"),
		Entry("-6", &six, "-6"),
	)
})

When running the test, it fails for building the tree:

Assertion or Panic detected during tree construction
DescribeTable("table with ctx", func(ctx context.Context, num *int, s string) {
/home/nunnatsa/GIT/ginkgo-test/tests/ttt_test.go:31
  Ginkgo detected a panic while constructing the spec tree.
  You may be trying to make an assertion in the body of a container node
  (i.e. Describe, Context, or When).

  Please ensure all assertions are inside leaf nodes such as BeforeEach,
  It, etc.

  Here's the content of the panic that was caught:
  runtime error: invalid memory address or nil pointer dereference

  Learn more at: http://onsi.github.io/ginkgo/#no-assertions-in-container-nodes

Notes:

• This is not happening if num is not a pointer.
• This is not happening if there is no context parameter.

Additional info:

The cause is the nil parameter in the first Entry.

The panic is from here:

ginkgo/table_dsl.go

Line 275 in fcf1fd7

} else if internalBodyType.In(0).Implements(contextType) && (len(entry.parameters) == 0 || !reflect.TypeOf(entry.parameters[0]).Implements(contextType)) {

entry.parameters[0] is nil, so reflect.TypeOf(entry.parameters[0]) is also nil, and then reflect.TypeOf(entry.parameters[0]).Implements(contextType)) panics.

[onsi]

hey @nunnatsa thanks for reporting this. i have a fix on master now and will cut a release soon