From 5315a37c08c77510d2b039408e89746bb1b421f9 Mon Sep 17 00:00:00 2001
From: Josh Bleecher Snyder <josharian@gmail.com>
Date: Thu, 28 Jan 2021 14:23:22 -0800
Subject: [PATCH] add IPSet.Equal

Signed-off-by: Josh Bleecher Snyder <josharian@gmail.com>
---
 ipset.go      | 15 +++++++++++++++
 ipset_test.go | 32 ++++++++++++++++++++++++++++++++
 2 files changed, 47 insertions(+)

diff --git a/ipset.go b/ipset.go
index a98caaa..f6cf7f4 100644
--- a/ipset.go
+++ b/ipset.go
@@ -309,3 +309,18 @@ func (s *IPSet) ContainsFunc() (contains func(IP) bool) {
 		return rv[i].contains(ip)
 	}
 }
+
+// Equal reports whether s contains exactly the same IPs as t.
+func (s *IPSet) Equal(t *IPSet) bool {
+	sr := s.Ranges()
+	tr := t.Ranges()
+	if len(sr) != len(tr) {
+		return false
+	}
+	for i := range sr {
+		if sr[i] != tr[i] {
+			return false
+		}
+	}
+	return true
+}
diff --git a/ipset_test.go b/ipset_test.go
index 092b25f..b88ffdc 100644
--- a/ipset_test.go
+++ b/ipset_test.go
@@ -701,3 +701,35 @@ func TestIPSetRangesStress(t *testing.T) {
 		}
 	}
 }
+
+func TestIPSetEqual(t *testing.T) {
+	a := new(IPSet)
+	b := new(IPSet)
+
+	assertEqual := func(want bool) {
+		t.Helper()
+		if got := a.Equal(b); got != want {
+			t.Errorf("%v.Equal(%v) = %v want %v", a, b, got, want)
+		}
+	}
+
+	a.Add(MustParseIP("1.1.1.0"))
+	a.Add(MustParseIP("1.1.1.1"))
+	a.Add(MustParseIP("1.1.1.2"))
+	b.AddPrefix(MustParseIPPrefix("1.1.1.0/31"))
+	b.Add(MustParseIP("1.1.1.2"))
+	assertEqual(true)
+
+	a.RemoveSet(a)
+	assertEqual(false)
+	b.RemoveSet(b)
+	assertEqual(true)
+
+	a.Add(MustParseIP("1.1.1.0"))
+	a.Add(MustParseIP("1.1.1.1"))
+	a.Add(MustParseIP("1.1.1.2"))
+
+	b.AddPrefix(MustParseIPPrefix("1.1.1.0/30"))
+	b.Remove(MustParseIP("1.1.1.3"))
+	assertEqual(true)
+}