blob: 25b4bd05bd7d07402bfde7be43df50858184a600 (
plain) (
blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
|
// Copyright 2018, The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package cmpopts
import (
"github.com/google/go-cmp/cmp"
)
type xformFilter struct{ xform cmp.Option }
func (xf xformFilter) filter(p cmp.Path) bool {
for _, ps := range p {
if t, ok := ps.(cmp.Transform); ok && t.Option() == xf.xform {
return false
}
}
return true
}
// AcyclicTransformer returns a [cmp.Transformer] with a filter applied that ensures
// that the transformer cannot be recursively applied upon its own output.
//
// An example use case is a transformer that splits a string by lines:
//
// AcyclicTransformer("SplitLines", func(s string) []string{
// return strings.Split(s, "\n")
// })
//
// Had this been an unfiltered [cmp.Transformer] instead, this would result in an
// infinite cycle converting a string to []string to [][]string and so on.
func AcyclicTransformer(name string, xformFunc interface{}) cmp.Option {
xf := xformFilter{cmp.Transformer(name, xformFunc)}
return cmp.FilterPath(xf.filter, xf.xform)
}
|
