Fix generic equality with nil

generics/compare.go

@@ -7,6 +7,9 @@ import (
 
 // Equal returns a bool indicating whether a == b after conversion.
 func Equal(a, b interface{}) bool {
+	if a == nil || b == nil {
+		return a == b
+	}
 	return genericCompare(reflect.ValueOf(a), reflect.ValueOf(b)) == 0
 }
 
@@ -71,7 +74,6 @@ func genericCompare(a, b reflect.Value) int {
 		return genericSameTypeCompare(a.Interface(), b.Interface())
 	}
 	ak, bk := a.Kind(), b.Kind()
-	// _ = ak.Convert
 	switch a.Kind() {
 	case reflect.Bool:
 		if b.Kind() == reflect.Bool {

generics/generics_test.go

@@ -7,7 +7,23 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
-var comparisonTests = []struct {
+var eqTests = []struct {
+	a, b     interface{}
+	expected bool
+}{
+	{0, 1, false},
+	{1, 1, true},
+	{1.0, 1.0, true},
+	{"a", "b", false},
+	{"a", "a", true},
+	{nil, nil, true},
+	{nil, 1, false},
+	{1, nil, false},
+	{false, false, true},
+	{false, true, false},
+}
+
+var lessTests = []struct {
 	a, b     interface{}
 	expected bool
 }{
@@ -25,8 +41,17 @@ var comparisonTests = []struct {
 	{false, true, true},
 }
 
+func TestEqual(t *testing.T) {
+	for i, test := range eqTests {
+		t.Run(fmt.Sprint(i), func(t *testing.T) {
+			value := Equal(test.a, test.b)
+			require.Equalf(t, test.expected, value, "%v < %v", test.a, test.b)
+		})
+	}
+}
+
 func TestLess(t *testing.T) {
-	for i, test := range comparisonTests {
+	for i, test := range lessTests {
 		t.Run(fmt.Sprint(i), func(t *testing.T) {
 			value := Less(test.a, test.b)
 			require.Equalf(t, test.expected, value, "%v < %v", test.a, test.b)