Merge pull request #1531 from arjunmahishi/fix-equal-values

assert: Fix EqualValues to handle overflow/underflow

Author: brackendawson

assert/assertions.go

@@ -165,17 +165,40 @@ func ObjectsAreEqualValues(expected, actual interface{}) bool {
 		return true
 	}
 
-	actualType := reflect.TypeOf(actual)
-	if actualType == nil {
+	expectedValue := reflect.ValueOf(expected)
+	actualValue := reflect.ValueOf(actual)
+	if !expectedValue.IsValid() || !actualValue.IsValid() {
 		return false
 	}
-	expectedValue := reflect.ValueOf(expected)
-	if expectedValue.IsValid() && expectedValue.Type().ConvertibleTo(actualType) {
+
+	expectedType := expectedValue.Type()
+	actualType := actualValue.Type()
+	if !expectedType.ConvertibleTo(actualType) {
+		return false
+	}
+
+	if !isNumericType(expectedType) || !isNumericType(actualType) {
 		// Attempt comparison after type conversion
-		return reflect.DeepEqual(expectedValue.Convert(actualType).Interface(), actual)
+		return reflect.DeepEqual(
+			expectedValue.Convert(actualType).Interface(), actual,
+		)
 	}
 
-	return false
+	// If BOTH values are numeric, there are chances of false positives due
+	// to overflow or underflow. So, we need to make sure to always convert
+	// the smaller type to a larger type before comparing.
+	if expectedType.Size() >= actualType.Size() {
+		return actualValue.Convert(expectedType).Interface() == expected
+	}
+
+	return expectedValue.Convert(actualType).Interface() == actual
+}
+
+// isNumericType returns true if the type is one of:
+// int, int8, int16, int32, int64, uint, uint8, uint16, uint32, uint64,
+// float32, float64, complex64, complex128
+func isNumericType(t reflect.Type) bool {
+	return t.Kind() >= reflect.Int && t.Kind() <= reflect.Complex128
 }
 
 /* CallerInfo is necessary because the assert functions use the testing object

assert/assertions_test.go

@@ -135,24 +135,42 @@ func TestObjectsAreEqual(t *testing.T) {
 
 		})
 	}
+}
 
-	// Cases where type differ but values are equal
-	if !ObjectsAreEqualValues(uint32(10), int32(10)) {
-		t.Error("ObjectsAreEqualValues should return true")
-	}
-	if ObjectsAreEqualValues(0, nil) {
-		t.Fail()
-	}
-	if ObjectsAreEqualValues(nil, 0) {
-		t.Fail()
-	}
+func TestObjectsAreEqualValues(t *testing.T) {
+	now := time.Now()
 
-	tm := time.Now()
-	tz := tm.In(time.Local)
-	if !ObjectsAreEqualValues(tm, tz) {
-		t.Error("ObjectsAreEqualValues should return true for time.Time objects with different time zones")
+	cases := []struct {
+		expected interface{}
+		actual   interface{}
+		result   bool
+	}{
+		{uint32(10), int32(10), true},
+		{0, nil, false},
+		{nil, 0, false},
+		{now, now.In(time.Local), true}, // should be time zone independent
+		{int(270), int8(14), false},     // should handle overflow/underflow
+		{int8(14), int(270), false},
+		{[]int{270, 270}, []int8{14, 14}, false},
+		{complex128(1e+100 + 1e+100i), complex64(complex(math.Inf(0), math.Inf(0))), false},
+		{complex64(complex(math.Inf(0), math.Inf(0))), complex128(1e+100 + 1e+100i), false},
+		{complex128(1e+100 + 1e+100i), 270, false},
+		{270, complex128(1e+100 + 1e+100i), false},
+		{complex128(1e+100 + 1e+100i), 3.14, false},
+		{3.14, complex128(1e+100 + 1e+100i), false},
+		{complex128(1e+10 + 1e+10i), complex64(1e+10 + 1e+10i), true},
+		{complex64(1e+10 + 1e+10i), complex128(1e+10 + 1e+10i), true},
 	}
 
+	for _, c := range cases {
+		t.Run(fmt.Sprintf("ObjectsAreEqualValues(%#v, %#v)", c.expected, c.actual), func(t *testing.T) {
+			res := ObjectsAreEqualValues(c.expected, c.actual)
+
+			if res != c.result {
+				t.Errorf("ObjectsAreEqualValues(%#v, %#v) should return %#v", c.expected, c.actual, c.result)
+			}
+		})
+	}
 }
 
 type Nested struct {