| 119 | } |
| 120 | |
| 121 | func TestSub(t *testing.T) { |
| 122 | x := errors.New("x") |
| 123 | y := errors.New("y") |
| 124 | cases := []struct{ new, old, want error }{ |
| 125 | {nil, nil, nil}, |
| 126 | {x, nil, nil}, |
| 127 | {nil, Wrap(y), nil}, |
| 128 | {Wrap(x), nil, nil}, |
| 129 | {nil, y, nil}, |
| 130 | {x, y, errors.New("y: x")}, |
| 131 | {Wrap(x), y, errors.New("y: x")}, |
| 132 | {x, Wrap(y), errors.New("y: x")}, |
| 133 | {Wrap(x, "z"), Wrap(y), errors.New("y: z: x")}, |
| 134 | } |
| 135 | |
| 136 | for _, test := range cases { |
| 137 | got := Sub(test.new, test.old) |
| 138 | if !(got == nil && test.want == nil || got.Error() == test.want.Error()) { |
| 139 | t.Errorf("Sub(%#v, %#v) = %v, want %v", test.new, test.old, got, test.want) |
| 140 | } |
| 141 | } |
| 142 | } |