detects properties without contents as diff

[dionysius]

Test case:

package main

import (
	"bytes"
	"testing"

	"github.com/sters/yaml-diff/yamldiff"
	core "k8s.io/api/core/v1"
	"k8s.io/apimachinery/pkg/runtime"
	k8sJson "k8s.io/apimachinery/pkg/runtime/serializer/json"
)

var (
	k8sScheme         = runtime.NewScheme()
	k8sYamlSerializer = k8sJson.NewYAMLSerializer(k8sJson.DefaultMetaFactory, k8sScheme, k8sScheme)
)

var podYaml = `apiVersion: v1
kind: Pod
metadata:
  namespace: default
  name: nginx
spec:
  containers:
  - name: nginx
    image: nginx
`

func Test_PodYamlDiff(t *testing.T) {
	t.Parallel()

	yamlSource, err := yamldiff.Load(podYaml)
	if err != nil {
		t.Error(err)
	}

	buf := bytes.NewBuffer([]byte{})
	pod := &core.Pod{}

	_, _, err = k8sYamlSerializer.Decode([]byte(podYaml), nil, pod)
	if err != nil {
		t.Error(err)
	}

	err = k8sYamlSerializer.Encode(pod, buf)
	if err != nil {
		t.Error(err)
	}

	yamlParsed, err := yamldiff.Load(buf.String())
	if err != nil {
		t.Error(err)
	}

	diffs := yamldiff.Do(yamlSource, yamlParsed)
	if len(diffs) > 0 {
		for _, diff := range diffs {
			t.Log("diff detected\n" + diff.Dump())
		}

		t.Fail()
	}
}

Test result:

--- FAIL: Test_PodYamlDiff (0.01s)
    main_test.go:57: diff detected
          apiVersion: "v1"
          kind: "Pod"
          metadata:
            namespace: "default"
            name: "nginx"
            creationTimestamp: <nil>
          spec:
            containers:
              - 
                name: "nginx"
                image: "nginx"
        +       resources:
        + status:

It does not diff for creationTimestamp: <nil>, which seems to be a intentional, so this test case above should not throw a diff for empty properties either?

[sters]

@dionysius

The fact that the key is there doesn't change even if there is an empty field. It's diff as a YAML document.

But I know k8s and other tools will ignore empty values and perform as default. So maybe it's better to make an option such as --ignore-empty-fields.

[dionysius]

Yeah, the existence of a key may have a meaning and should be treated as such. ignore-empty-fields sounds like a good compromise.

Although since we defined now that additional keys trigger a diff, that should also happen on creationTimestamp

[sters]

@dionysius
Updated. https://github.com/sters/yaml-diff/releases/tag/v1.1.0

You can do:

diffs := yamldiff.Do(yamlSource, yamlParsed, yamldiff.EmptyAsNull())

and diff result is:

  apiVersion: "v1"
  kind: "Pod"
  metadata:
    namespace: "default"
    name: "nginx"
    creationTimestamp:
  spec:
    containers:
      -
        name: "nginx"
        image: "nginx"
        resources:
  status:

Also, I added Status field in diff struct. You can refer to this field to detect whether there is diff or not. So you can do:

diffs := yamldiff.Do(yamlSource, yamlParsed, yamldiff.EmptyAsNull())

fail := false
for _, diff := range diffs {
	if diff.Status() != yamldiff.DiffStatusSame {
		fail = true
		t.Log("diff detected\n" + diff.Dump())
	}
}

if fail {
	t.Fail()
}

[dionysius]

Thanks for everything. Will check and report!

[sters]

If you have more conversation, please reopen (or recreate) issue.