image: avoid sharing test images between tests and benchmarks

CL 136796 introduced benchmarks and refactored tests to use a
common list of test images. The tests now fail when run with
count > 2 since they rely on a fresh image each run.

Fix this by changing the list of test images to a list of test
image generator functions.

Change-Id: I5884c6bccba5e29bf84ee546fa501bc258379f42
Reviewed-on: https://go-review.googlesource.com/137295
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

diff --git a/src/image/image_test.go b/src/image/image_test.go
index 6f49752a25fb4d44a8fd2f8dc76e7ae33dcf039e..dfd8eb35a804db7b858f47ac3c088e302e9d5869 100644 (file)
--- a/src/image/image_test.go
+++ b/src/image/image_test.go
@@ -24,25 +24,27 @@ func cmp(cm color.Model, c0, c1 color.Color) bool {
 
 var testImages = []struct {
        name  string
-       image image
+       image func() image
 }{
-       {"rgba", NewRGBA(Rect(0, 0, 10, 10))},
-       {"rgba64", NewRGBA64(Rect(0, 0, 10, 10))},
-       {"nrgba", NewNRGBA(Rect(0, 0, 10, 10))},
-       {"nrgba64", NewNRGBA64(Rect(0, 0, 10, 10))},
-       {"alpha", NewAlpha(Rect(0, 0, 10, 10))},
-       {"alpha16", NewAlpha16(Rect(0, 0, 10, 10))},
-       {"gray", NewGray(Rect(0, 0, 10, 10))},
-       {"gray16", NewGray16(Rect(0, 0, 10, 10))},
-       {"paletted", NewPaletted(Rect(0, 0, 10, 10), color.Palette{
-               Transparent,
-               Opaque,
-       })},
+       {"rgba", func() image { return NewRGBA(Rect(0, 0, 10, 10)) }},
+       {"rgba64", func() image { return NewRGBA64(Rect(0, 0, 10, 10)) }},
+       {"nrgba", func() image { return NewNRGBA(Rect(0, 0, 10, 10)) }},
+       {"nrgba64", func() image { return NewNRGBA64(Rect(0, 0, 10, 10)) }},
+       {"alpha", func() image { return NewAlpha(Rect(0, 0, 10, 10)) }},
+       {"alpha16", func() image { return NewAlpha16(Rect(0, 0, 10, 10)) }},
+       {"gray", func() image { return NewGray(Rect(0, 0, 10, 10)) }},
+       {"gray16", func() image { return NewGray16(Rect(0, 0, 10, 10)) }},
+       {"paletted", func() image {
+               return NewPaletted(Rect(0, 0, 10, 10), color.Palette{
+                       Transparent,
+                       Opaque,
+               })
+       }},
 }
 
 func TestImage(t *testing.T) {
        for _, tc := range testImages {
-               m := tc.image
+               m := tc.image()
                if !Rect(0, 0, 10, 10).Eq(m.Bounds()) {
                        t.Errorf("%T: want bounds %v, got %v", m, Rect(0, 0, 10, 10), m.Bounds())
                        continue
@@ -120,9 +122,11 @@ func Test16BitsPerColorChannel(t *testing.T) {
 func BenchmarkAt(b *testing.B) {
        for _, tc := range testImages {
                b.Run(tc.name, func(b *testing.B) {
+                       m := tc.image()
                        b.ReportAllocs()
+                       b.ResetTimer()
                        for i := 0; i < b.N; i++ {
-                               tc.image.At(4, 5)
+                               m.At(4, 5)
                        }
                })
        }
@@ -132,9 +136,11 @@ func BenchmarkSet(b *testing.B) {
        c := color.Gray{0xff}
        for _, tc := range testImages {
                b.Run(tc.name, func(b *testing.B) {
+                       m := tc.image()
                        b.ReportAllocs()
+                       b.ResetTimer()
                        for i := 0; i < b.N; i++ {
-                               tc.image.Set(4, 5, c)
+                               m.Set(4, 5, c)
                        }
                })
        }