helm-controller/internal/cmp/simple_unstructured.go

110 lines
2.7 KiB
Go

/*
Copyright 2023 The Flux authors
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
package cmp
import (
"fmt"
"reflect"
"strings"
"github.com/google/go-cmp/cmp"
)
// SimpleUnstructuredReporter is a simple reporter for Unstructured objects
// that only records differences detected during comparison, in a diff-like
// format.
type SimpleUnstructuredReporter struct {
path cmp.Path
diffs []string
}
// Report writes a diff entry if rs is not equal. In the format of:
//
// .spec.replicas
// -3
// +1
//
// .spec.template.spec.containers.[0].command.[6]
// ---deleted=true
//
// .spec.template.spec.containers.[0].env.[?->1]
// +map[name:ADDED]
func (r *SimpleUnstructuredReporter) Report(rs cmp.Result) {
if !rs.Equal() {
vx, vy := r.path.Last().Values()
isNonEmptyX := isValidAndNonEmpty(vx)
isNonEmptyY := isValidAndNonEmpty(vy)
if !isNonEmptyX && !isNonEmptyY {
// Skip empty values.
return
}
var sb strings.Builder
writePathString(r.path, &sb)
sb.WriteString("\n")
if isNonEmptyX {
sb.WriteString(fmt.Sprintf("-%v", vx))
sb.WriteString("\n")
}
if isNonEmptyY {
sb.WriteString(fmt.Sprintf("+%v", vy))
sb.WriteString("\n")
}
r.diffs = append(r.diffs, sb.String())
}
}
// String returns the diff entries joined together with newline, trimmed from
// spaces.
func (r *SimpleUnstructuredReporter) String() string {
return strings.TrimSpace(strings.Join(r.diffs, "\n"))
}
func (r *SimpleUnstructuredReporter) PushStep(ps cmp.PathStep) {
r.path = append(r.path, ps)
}
func (r *SimpleUnstructuredReporter) PopStep() {
r.path = r.path[:len(r.path)-1]
}
// https://github.com/istio/istio/blob/2caf81c64a2213dde39174a0a36cae530dc52b69/operator/pkg/compare/compare.go#L79
func isValidAndNonEmpty(v reflect.Value) bool {
if !v.IsValid() {
return false
}
switch v.Kind() {
case reflect.Interface:
return isValidAndNonEmpty(v.Elem())
case reflect.Array, reflect.Chan, reflect.Map, reflect.Slice, reflect.String:
return v.Len() > 0
}
return true
}
func writePathString(path cmp.Path, sb *strings.Builder) {
for _, st := range path {
switch t := st.(type) {
case cmp.MapIndex:
sb.WriteString(fmt.Sprintf(".%v", t.Key()))
case cmp.SliceIndex:
sb.WriteString(fmt.Sprintf("%v", t.String()))
}
}
}