move HasConflicts to shareable location

pkg/util/strategicpatch/patch.go

@@ -827,3 +827,44 @@ func sliceElementType(slices ...[]interface{}) (reflect.Type, error) {
 
 	return prevType, nil
 }
+
+// HasConflicts returns true if the left and right JSON interface objects overlap with
+// different values in any key.  The code will panic if an unrecognized type is passed
+// (anything not returned by a JSON decode).  All keys are required to be strings.
+// Since patches of the same Type have congruent keys, this is valid for multiple patch
+// types.
+func HasConflicts(left, right interface{}) (bool, error) {
+	switch typedLeft := left.(type) {
+	case map[string]interface{}:
+		switch typedRight := right.(type) {
+		case map[string]interface{}:
+			for key, leftValue := range typedLeft {
+				rightValue, ok := typedRight[key]
+				if !ok {
+					return false, nil
+				}
+				return HasConflicts(leftValue, rightValue)
+			}
+			return false, nil
+		default:
+			return true, nil
+		}
+	case []interface{}:
+		switch typedRight := right.(type) {
+		case []interface{}:
+			if len(typedLeft) != len(typedRight) {
+				return true, nil
+			}
+			for i := range typedLeft {
+				return HasConflicts(typedLeft[i], typedRight[i])
+			}
+			return false, nil
+		default:
+			return true, nil
+		}
+	case string, float64, bool, int, int64, nil:
+		return !reflect.DeepEqual(left, right), nil
+	default:
+		return true, fmt.Errorf("unknown type: %v", reflect.TypeOf(left))
+	}
+}

pkg/util/strategicpatch/patch_test.go

@@ -764,3 +764,66 @@ func jsonToYAML(j []byte) ([]byte, error) {
 
 	return y, nil
 }
+
+func TestHasConflicts(t *testing.T) {
+	testCases := []struct {
+		A   interface{}
+		B   interface{}
+		Ret bool
+	}{
+		{A: "hello", B: "hello", Ret: false}, // 0
+		{A: "hello", B: "hell", Ret: true},
+		{A: "hello", B: nil, Ret: true},
+		{A: "hello", B: 1, Ret: true},
+		{A: "hello", B: float64(1.0), Ret: true},
+		{A: "hello", B: false, Ret: true},
+		{A: 1, B: 1, Ret: false},
+		{A: false, B: false, Ret: false},
+		{A: float64(3), B: float64(3), Ret: false},
+
+		{A: "hello", B: []interface{}{}, Ret: true}, // 6
+		{A: []interface{}{1}, B: []interface{}{}, Ret: true},
+		{A: []interface{}{}, B: []interface{}{}, Ret: false},
+		{A: []interface{}{1}, B: []interface{}{1}, Ret: false},
+		{A: map[string]interface{}{}, B: []interface{}{1}, Ret: true},
+
+		{A: map[string]interface{}{}, B: map[string]interface{}{"a": 1}, Ret: false}, // 11
+		{A: map[string]interface{}{"a": 1}, B: map[string]interface{}{"a": 1}, Ret: false},
+		{A: map[string]interface{}{"a": 1}, B: map[string]interface{}{"a": 2}, Ret: true},
+		{A: map[string]interface{}{"a": 1}, B: map[string]interface{}{"b": 2}, Ret: false},
+
+		{ // 15
+			A:   map[string]interface{}{"a": []interface{}{1}},
+			B:   map[string]interface{}{"a": []interface{}{1}},
+			Ret: false,
+		},
+		{
+			A:   map[string]interface{}{"a": []interface{}{1}},
+			B:   map[string]interface{}{"a": []interface{}{}},
+			Ret: true,
+		},
+		{
+			A:   map[string]interface{}{"a": []interface{}{1}},
+			B:   map[string]interface{}{"a": 1},
+			Ret: true,
+		},
+	}
+
+	for i, testCase := range testCases {
+		out, err := HasConflicts(testCase.A, testCase.B)
+		if err != nil {
+			t.Errorf("%d: unexpected error: %v", i, err)
+		}
+		if out != testCase.Ret {
+			t.Errorf("%d: expected %t got %t", i, testCase.Ret, out)
+			continue
+		}
+		out, err = HasConflicts(testCase.B, testCase.A)
+		if err != nil {
+			t.Errorf("%d: unexpected error: %v", i, err)
+		}
+		if out != testCase.Ret {
+			t.Errorf("%d: expected reversed %t got %t", i, testCase.Ret, out)
+		}
+	}
+}