Revert strict decoding of Kustomization due to regression in anchor handling

api/internal/localizer/localizer_test.go

@@ -263,7 +263,7 @@ suffix: invalid`,
 
 	_, err := Run("/a", "", "", fSysTest)
 	require.EqualError(t, err,
-		`unable to localize target "/a": invalid Kustomization: error unmarshaling JSON: while decoding JSON: json: unknown field "suffix"`)
+		`unable to localize target "/a": invalid Kustomization: json: unknown field "suffix"`)
 
 	checkFSys(t, fSysExpected, fSysTest)
 }

api/krusty/configmaps_test.go

@@ -6,7 +6,6 @@ package krusty_test
 import (
 	"testing"
 
-	"github.com/stretchr/testify/assert"
 	kusttest_test "sigs.k8s.io/kustomize/api/testutils/kusttest"
 )
 
@@ -229,6 +228,9 @@ type: Opaque
 `)
 }
 
+// TODO: This should be an error instead. However, we can't strict unmarshal until we have a yaml
+// lib that support case-insensitive keys and anchors.
+// See https://github.com/kubernetes-sigs/kustomize/issues/5061
 func TestGeneratorRepeatsInKustomization(t *testing.T) {
 	th := kusttest_test.MakeHarness(t)
 	th.WriteK(".", `
@@ -261,13 +263,24 @@ krypton
 xenon
 radon
 `)
-	err := th.RunWithErr(".", th.MakeDefaultOptions())
-	if err == nil {
-		t.Fatalf("expected an error")
-	}
-	assert.Contains(t, err.Error(),
-		"invalid Kustomization: error converting YAML to JSON: yaml: unmarshal errors:\n"+
-			"  line 13: key \"literals\" already set in map\n  line 18: key \"files\" already set in map")
+	m := th.Run(".", th.MakeDefaultOptions())
+	th.AssertActualEqualsExpected(m, `
+apiVersion: v1
+data:
+  fruit: apple
+  nobles: |2
+
+    helium
+    neon
+    argon
+    krypton
+    xenon
+    radon
+  vegetable: broccoli
+kind: ConfigMap
+metadata:
+  name: blah-bob-db529cg5bk
+`)
 }
 
 func TestIssue3393(t *testing.T) {

api/types/kustomization.go

@@ -4,6 +4,8 @@
 package types
 
 import (
+	"bytes"
+	"encoding/json"
 	"fmt"
 
 	"sigs.k8s.io/kustomize/kyaml/errors"
@@ -313,8 +315,20 @@ func (k *Kustomization) EnforceFields() []string {
 
 // Unmarshal replace k with the content in YAML input y
 func (k *Kustomization) Unmarshal(y []byte) error {
-	if err := yaml.UnmarshalStrict(y, &k); err != nil {
+	// TODO: switch to strict decoding to catch duplicate keys.
+	// We can't do so until there is a yaml decoder that supports anchors AND case-insensitive keys.
+	// See https://github.com/kubernetes-sigs/kustomize/issues/5061
+	j, err := yaml.YAMLToJSON(y)
+	if err != nil {
 		return errors.WrapPrefixf(err, "invalid Kustomization")
 	}
+	dec := json.NewDecoder(bytes.NewReader(j))
+	dec.DisallowUnknownFields()
+	var nk Kustomization
+	err = dec.Decode(&nk)
+	if err != nil {
+		return errors.WrapPrefixf(err, "invalid Kustomization")
+	}
+	*k = nk
 	return nil
 }

api/types/kustomization_test.go

@@ -278,7 +278,7 @@ unknown: foo`)
 	if err == nil {
 		t.Fatalf("expect an error")
 	}
-	expect := "invalid Kustomization: error unmarshaling JSON: while decoding JSON: json: unknown field \"unknown\""
+	expect := "invalid Kustomization: json: unknown field \"unknown\""
 	if err.Error() != expect {
 		t.Fatalf("expect %v but got: %v", expect, err.Error())
 	}

kustomize/commands/internal/kustfile/kustomizationfile_test.go

@@ -382,7 +382,7 @@ foo:
 	}
 
 	_, err = mf.Read()
-	if err == nil || err.Error() != "invalid Kustomization: error unmarshaling JSON: while decoding JSON: json: unknown field \"foo\"" {
+	if err == nil || err.Error() != "invalid Kustomization: json: unknown field \"foo\"" {
 		t.Fatalf("Expect an unknown field error but got: %v", err)
 	}
 }