From b1b7eca0eb9b2fe3024de5b0561f8133458d5fba Mon Sep 17 00:00:00 2001
From: Aleksandr Rybolovlev <sacha.rybolovlev@hashicorp.com>
Date: Thu, 4 Jan 2024 09:40:00 +0100
Subject: [PATCH] Update slice.DeepEqual and its unit test

---
 internal/slice/slice.go      | 27 +++++++------
 internal/slice/slice_test.go | 77 ++++++++++++++++++++++++------------
 2 files changed, 68 insertions(+), 36 deletions(-)

diff --git a/internal/slice/slice.go b/internal/slice/slice.go
index d0007838..c8efe4f4 100644
--- a/internal/slice/slice.go
+++ b/internal/slice/slice.go
@@ -26,25 +26,30 @@ func DeepEqual[A any](a, b []A) bool {
 	}
 
 	if a == nil || b == nil {
-		return true
+		return cmp.Equal(a, b)
 	}
 
 	if reflect.TypeOf(a) != reflect.TypeOf(b) {
 		return false
 	}
 
-	for _, va := range a {
-		found := false
-		for _, vb := range b {
-			if cmp.Equal(va, vb) {
-				found = true
-				break
-			}
-		}
-		if !found {
+	ma := make(map[any]int)
+	mb := make(map[any]int)
+
+	for i := 0; i < len(a); i++ {
+		ma[a[i]]++
+		mb[b[i]]++
+	}
+
+	for va := range ma {
+		if _, ok := mb[va]; !ok {
 			return false
 		}
+		mb[va]--
+		if mb[va] == 0 {
+			delete(mb, va)
+		}
 	}
 
-	return true
+	return len(mb) == 0
 }
diff --git a/internal/slice/slice_test.go b/internal/slice/slice_test.go
index bf72d8fd..4d3521f9 100644
--- a/internal/slice/slice_test.go
+++ b/internal/slice/slice_test.go
@@ -26,44 +26,71 @@ func TestRemoveFromSlice(t *testing.T) {
 }
 
 func TestDeepEqual(t *testing.T) {
-	input := []map[string][]any{
+	cases := []struct {
+		A        []any
+		B        []any
+		Expected bool
+	}{
 		{
-			"A": {},
-			"B": {},
+			A:        []any{},
+			B:        []any{},
+			Expected: true,
 		},
 		{
-			"A": nil,
-			"B": nil,
+			A:        nil,
+			B:        nil,
+			Expected: true,
 		},
 		{
-			"A": {},
-			"B": nil,
+			A:        []any{1, 2, 3},
+			B:        []any{1, 2, 3},
+			Expected: true,
 		},
 		{
-			"A": {1, 2, 3},
-			"B": {1, 2, 3},
+			A:        []any{1, 2, 3},
+			B:        []any{3, 1, 2},
+			Expected: true,
 		},
 		{
-			"A": {"a", "b", "c"},
-			"B": {"b", "c"},
+			A:        []any{},
+			B:        nil,
+			Expected: false,
 		},
 		{
-			"A": {1, 2},
-			"B": {"b", "c"},
+			A:        nil,
+			B:        []any{1, 2, 3},
+			Expected: false,
+		},
+		{
+			A:        []any{1, 1, 1, 2, 3},
+			B:        []any{1, 1, 2, 2, 3},
+			Expected: false,
+		},
+		{
+			A:        []any{"a", "b", "c"},
+			B:        []any{"b", "c"},
+			Expected: false,
+		},
+		{
+			A:        []any{1, 2},
+			B:        []any{"b", "c"},
+			Expected: false,
+		},
+		{
+			A:        []any{1, 1},
+			B:        []any{1, 5},
+			Expected: false,
+		},
+		{
+			A:        []any{1, 5},
+			B:        []any{1, 1},
+			Expected: false,
 		},
 	}
-	want := []bool{
-		true,
-		true,
-		true,
-		true,
-		false,
-		false,
-	}
-	for i, s := range input {
-		r := DeepEqual(s["A"], s["B"])
-		if r != want[i] {
-			t.Errorf("The wanted result [%t] does not match with the produced [%v] at [%d]", want[i], r, i)
+	for i, s := range cases {
+		r := DeepEqual(s.A, s.B)
+		if r != s.Expected {
+			t.Errorf("The wanted result [%t] does not match with the produced [%v] at [%d]", s.Expected, r, i)
 		}
 	}
 }