pruning: add 'Negate' option to KeepRegex and expose it in config

pruning/keep_regex_test.go

@@ -0,0 +1,32 @@
+package pruning
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestKeepRegexNegation(t *testing.T) {
+
+	noneg := MustKeepRegex("^zrepl_", false)
+	neg := MustKeepRegex("^zrepl_", true)
+
+	snaps := []Snapshot{
+		stubSnap{name: "zrepl_foobar"},
+		stubSnap{name: "zrepl"},
+		stubSnap{name: "barfoo"},
+	}
+
+	destroyNonNeg := snapshotList(noneg.KeepRule(snaps))
+	t.Logf("non-negated rule destroys: %#v", destroyNonNeg.NameList())
+	assert.True(t, destroyNonNeg.ContainsName("zrepl"))
+	assert.True(t, destroyNonNeg.ContainsName("barfoo"))
+	assert.False(t, destroyNonNeg.ContainsName("zrepl_foobar"))
+
+	destroyNeg := snapshotList(neg.KeepRule(snaps))
+	t.Logf("negated rule destroys: %#v", destroyNeg.NameList())
+	assert.False(t, destroyNeg.ContainsName("zrepl"))
+	assert.False(t, destroyNeg.ContainsName("barfoo"))
+	assert.True(t, destroyNeg.ContainsName("zrepl_foobar"))
+
+}