testing/quick: generate more map and slice states

This change adds support in testing/quick to generate maps and slices
in additional states:

  (1.) nil maps

  (2.) nil slices

  (3.) empty slice occupancy: `len(s) == 0 && s != nil`

  (4.) partial slice occupancy: `len(s) < cap(s) && s != nil`

  (5.) full slice occupancy: `len(s) == cap(s) && s != nil`

Prior to this, only #5 was ever generated, thereby not sufficiently
exercising all of the fuzzable code path outcomes.

This change depends on https://go-review.googlesource.com/#/c/17499/.

Change-Id: I9343c475cefbd72ffc5237281826465c25872206
Reviewed-on: https://go-review.googlesource.com/16470
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

1 files changed, 0 insertions, 17 deletions

diff --git a/src/testing/quick/quick_test.go b/src/testing/quick/quick_test.go
index fe443592f8..018ece2a52 100644
--- a/src/testing/quick/quick_test.go
+++ b/src/testing/quick/quick_test.go
@@ -290,20 +290,3 @@ func TestMutuallyRecursive(t *testing.T) {
 	f := func(a A) bool { return true }
 	Check(f, nil)
 }
-
-// Some serialization formats (e.g. encoding/pem) cannot distinguish
-// between a nil and an empty map or slice, so avoid generating the
-// zero value for these.
-func TestNonZeroSliceAndMap(t *testing.T) {
-	type Q struct {
-		M map[int]int
-		S []int
-	}
-	f := func(q Q) bool {
-		return q.M != nil && q.S != nil
-	}
-	err := Check(f, nil)
-	if err != nil {
-		t.Fatal(err)
-	}
-}