Adding option to suppress empty output files

Signed-off-by: Dave Henderson <dhenderson@gmail.com>

1 files changed, 57 insertions, 0 deletions

diff --git a/template_test.go b/template_test.go
index 190fb35f..fb71ecea 100644
--- a/template_test.go
+++ b/template_test.go
@@ -295,3 +295,60 @@ func TestProcessTemplates(t *testing.T) {
 		fs.Remove("out")
 	}
 }
+
+func TestAllWhitespace(t *testing.T) {
+	testdata := []struct {
+		in       []byte
+		expected bool
+	}{
+		{[]byte(" "), true},
+		{[]byte("foo"), false},
+		{[]byte("   \t\n\n\v\r\n"), true},
+		{[]byte("   foo   "), false},
+	}
+
+	for _, d := range testdata {
+		assert.Equal(t, d.expected, allWhitespace(d.in))
+	}
+}
+
+func TestEmptySkipper(t *testing.T) {
+	testdata := []struct {
+		in    []byte
+		empty bool
+	}{
+		{[]byte(" "), true},
+		{[]byte("foo"), false},
+		{[]byte("   \t\n\n\v\r\n"), true},
+		{[]byte("   foo   "), false},
+	}
+
+	for _, d := range testdata {
+		w := &bufferCloser{&bytes.Buffer{}}
+		opened := false
+		f := newEmptySkipper(func() (io.WriteCloser, error) {
+			t.Logf("I got called %#v", w)
+			opened = true
+			return w, nil
+		})
+		n, err := f.Write(d.in)
+		assert.NoError(t, err)
+		assert.Equal(t, len(d.in), n)
+		if d.empty {
+			assert.Nil(t, f.w)
+			assert.False(t, opened)
+		} else {
+			assert.NotNil(t, f.w)
+			assert.True(t, opened)
+			assert.EqualValues(t, d.in, w.Bytes())
+		}
+	}
+}
+
+type bufferCloser struct {
+	*bytes.Buffer
+}
+
+func (b *bufferCloser) Close() error {
+	return nil
+}