Add a test case for issue 4905

```
===== ACTUAL BEGIN ========================================
apiVersion: v1
data:
  config.yaml: "null"
kind: ConfigMap
metadata:
  name: issue4905
===== ACTUAL END ==========================================
   EXPECTED              ACTUAL
   --------              ------
   apiVersion: v1        apiVersion: v1
   data:                 data:
X    config.yaml: |-       config.yaml: "null"
X      item1: 1          kind: ConfigMap
X      item2: 2          metadata:
X  kind: ConfigMap         name: issue4905
X  metadata:
X    name: issue4905
    hasgett.go:22: Expected not equal to actual
--- FAIL: TestHelmChartInflationGeneratorIssue4905 (0.24s)
```

Signed-off-by: Kazuki Suda <kazuki.suda@gmail.com>

plugin/builtin/helmchartinflationgenerator/HelmChartInflationGenerator_test.go

@@ -9,7 +9,9 @@ import (
 	"path/filepath"
 	"testing"
 
+	"github.com/stretchr/testify/require"
 	kusttest_test "sigs.k8s.io/kustomize/api/testutils/kusttest"
+	"sigs.k8s.io/kustomize/kyaml/copyutil"
 )
 
 func TestHelmChartInflationGenerator(t *testing.T) {
@@ -579,3 +581,48 @@ valuesInline:
 `)
 	th.AssertActualEqualsExpected(rm, "")
 }
+
+func TestHelmChartInflationGeneratorIssue4905(t *testing.T) {
+	th := kusttest_test.MakeEnhancedHarnessWithTmpRoot(t).
+		PrepBuiltin("HelmChartInflationGenerator")
+	defer th.Reset()
+	if err := th.ErrIfNoHelm(); err != nil {
+		t.Skip("skipping: " + err.Error())
+	}
+
+	copyTestChartsIntoHarness(t, th)
+
+	rm := th.LoadAndRunGenerator(`
+apiVersion: builtin
+kind: HelmChartInflationGenerator
+metadata:
+  name: issue4905
+name: issue4905
+releaseName: issue4905
+chartHome: ./charts
+valuesInline:
+  config:
+    item1: 1
+    item2: 2
+`)
+
+	th.AssertActualEqualsExpected(rm, `
+apiVersion: v1
+data:
+  config.yaml: |-
+    item1: 1
+    item2: 2
+kind: ConfigMap
+metadata:
+  name: issue4905
+`)
+}
+
+func copyTestChartsIntoHarness(t *testing.T, th *kusttest_test.HarnessEnhanced) {
+	t.Helper()
+
+	thDir := filepath.Join(th.GetRoot(), "charts")
+	chartDir := "testdata/charts"
+
+	require.NoError(t, copyutil.CopyDir(th.GetFSys(), chartDir, thDir))
+}

plugin/builtin/helmchartinflationgenerator/go.mod

@@ -4,6 +4,7 @@ go 1.20
 
 require (
 	github.com/imdario/mergo v0.3.6
+	github.com/stretchr/testify v1.8.1
 	sigs.k8s.io/kustomize/api v0.14.0
 	sigs.k8s.io/kustomize/kyaml v0.14.3
 	sigs.k8s.io/yaml v1.3.0
@@ -25,7 +26,7 @@ require (
 	github.com/monochromegane/go-gitignore v0.0.0-20200626010858-205db1a8cc00 // indirect
 	github.com/pkg/errors v0.9.1 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
-	github.com/stretchr/testify v1.8.1 // indirect
+	github.com/sergi/go-diff v1.1.0 // indirect
 	github.com/xlab/treeprint v1.2.0 // indirect
 	go.starlark.net v0.0.0-20200306205701-8dd3e2ee1dd5 // indirect
 	golang.org/x/sys v0.8.0 // indirect

plugin/builtin/helmchartinflationgenerator/go.sum

@@ -29,6 +29,7 @@ github.com/imdario/mergo v0.3.6 h1:xTNEAn+kxVO7dTZGu0CegyqKZmoWFI0rF8UxjlB2d28=
 github.com/imdario/mergo v0.3.6/go.mod h1:2EnlNZ0deacrJVfApfmtdGgDfMuh/nq6Ok1EcJh5FfA=
 github.com/josharian/intern v1.0.0 h1:vlS4z54oSdjm0bgjRigI+G1HpF+tI+9rE5LLzOg8HmY=
 github.com/josharian/intern v1.0.0/go.mod h1:5DoeVV0s6jJacbCEi61lwdGj/aVlrQvzHFFd8Hwg//Y=
+github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=
 github.com/kr/pretty v0.2.1/go.mod h1:ipq/a2n7PKx3OHsz4KJII5eveXtPO4qwEXGdVfWzfnI=
 github.com/kr/pretty v0.3.0 h1:WgNl7dwNpEZ6jJ9k1snq4pZsg7DOEN8hP9Xw0Tsjwk0=
 github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
@@ -45,10 +46,12 @@ github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZb
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/rogpeppe/go-internal v1.10.0 h1:TMyTOH3F/DB16zRVcYyreMH6GnZZrwQVAoYjRBZyWFQ=
 github.com/sergi/go-diff v1.1.0 h1:we8PVUC3FE2uYfodKH/nBHMSetSfHDR6scGdBi+erh0=
+github.com/sergi/go-diff v1.1.0/go.mod h1:STckp+ISIX8hZLjrqAeVduY0gWCT9IjLuqbuNXdaHfM=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/objx v0.4.0/go.mod h1:YvHI0jy2hoMjB+UWwv71VJQ9isScKT/TqJzVSSt89Yw=
 github.com/stretchr/objx v0.5.0 h1:1zr/of2m5FGMsad5YfcqgdqdWrIhu+EBEJRhR1U7z/c=
 github.com/stretchr/objx v0.5.0/go.mod h1:Yh+to48EsGEfYuaHDzXPcE3xhTkx73EhmCGUpEOglKo=
+github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
 github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 github.com/stretchr/testify v1.8.0/go.mod h1:yNjHg4UonilssWZ8iaSj1OCr/vHnekPRkoO+kdMU+MU=
@@ -67,10 +70,13 @@ google.golang.org/protobuf v1.26.0/go.mod h1:9q0QmTI4eRPtz6boOQmLYwt+qCgq0jsYwAQ
 google.golang.org/protobuf v1.30.0 h1:kPPoIgf3TsEvrm0PFe15JQ+570QVxYzEvvHqChK+cng=
 google.golang.org/protobuf v1.30.0/go.mod h1:HV8QOd/L58Z+nl8r43ehVNZIU/HEI6OcFqwMG9pJV4I=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c h1:Hei/4ADfdWqJk1ZMxUNpqntNwaWcugrBjAiHlqqRiVk=
 gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c/go.mod h1:JHkPIbrfpd72SG/EVd6muEfDQjcINNoR0C8j2r3qZ4Q=
 gopkg.in/evanphx/json-patch.v5 v5.6.0 h1:BMT6KIwBD9CaU91PJCZIe46bDmBWa9ynTQgJIOpfQBk=
 gopkg.in/evanphx/json-patch.v5 v5.6.0/go.mod h1:/kvTRh1TVm5wuM6OkHxqXtE/1nUZZpihg29RtuIyfvk=
+gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
+gopkg.in/yaml.v2 v2.2.4/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 gopkg.in/yaml.v2 v2.4.0 h1:D8xgwECY7CYvx+Y2n4sBz93Jn9JRvxdiyyo8CTfuKaY=
 gopkg.in/yaml.v2 v2.4.0/go.mod h1:RDklbk79AGWmwhnvt/jBztapEOGDOx6ZbXqjP6csGnQ=
 gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

plugin/builtin/helmchartinflationgenerator/testdata/charts/issue4905/Chart.yaml

@@ -0,0 +1,24 @@
+apiVersion: v2
+name: issue4905
+description: A Helm chart for Kubernetes
+
+# A chart can be either an 'application' or a 'library' chart.
+#
+# Application charts are a collection of templates that can be packaged into versioned archives
+# to be deployed.
+#
+# Library charts provide useful utilities or functions for the chart developer. They're included as
+# a dependency of application charts to inject those utilities and functions into the rendering
+# pipeline. Library charts do not define any templates and therefore cannot be deployed.
+type: application
+
+# This is the chart version. This version number should be incremented each time you make changes
+# to the chart and its templates, including the app version.
+# Versions are expected to follow Semantic Versioning (https://semver.org/)
+version: 0.1.0
+
+# This is the version number of the application being deployed. This version number should be
+# incremented each time you make changes to the application. Versions are not expected to
+# follow Semantic Versioning. They should reflect the version the application is using.
+# It is recommended to use it with quotes.
+appVersion: "1.16.0"

plugin/builtin/helmchartinflationgenerator/testdata/charts/issue4905/templates/_helpers.tpl

@@ -0,0 +1,62 @@
+{{/*
+Expand the name of the chart.
+*/}}
+{{- define "issue4905.name" -}}
+{{- default .Chart.Name .Values.nameOverride | trunc 63 | trimSuffix "-" }}
+{{- end }}
+
+{{/*
+Create a default fully qualified app name.
+We truncate at 63 chars because some Kubernetes name fields are limited to this (by the DNS naming spec).
+If release name contains chart name it will be used as a full name.
+*/}}
+{{- define "issue4905.fullname" -}}
+{{- if .Values.fullnameOverride }}
+{{- .Values.fullnameOverride | trunc 63 | trimSuffix "-" }}
+{{- else }}
+{{- $name := default .Chart.Name .Values.nameOverride }}
+{{- if contains $name .Release.Name }}
+{{- .Release.Name | trunc 63 | trimSuffix "-" }}
+{{- else }}
+{{- printf "%s-%s" .Release.Name $name | trunc 63 | trimSuffix "-" }}
+{{- end }}
+{{- end }}
+{{- end }}
+
+{{/*
+Create chart name and version as used by the chart label.
+*/}}
+{{- define "issue4905.chart" -}}
+{{- printf "%s-%s" .Chart.Name .Chart.Version | replace "+" "_" | trunc 63 | trimSuffix "-" }}
+{{- end }}
+
+{{/*
+Common labels
+*/}}
+{{- define "issue4905.labels" -}}
+helm.sh/chart: {{ include "issue4905.chart" . }}
+{{ include "issue4905.selectorLabels" . }}
+{{- if .Chart.AppVersion }}
+app.kubernetes.io/version: {{ .Chart.AppVersion | quote }}
+{{- end }}
+app.kubernetes.io/managed-by: {{ .Release.Service }}
+{{- end }}
+
+{{/*
+Selector labels
+*/}}
+{{- define "issue4905.selectorLabels" -}}
+app.kubernetes.io/name: {{ include "issue4905.name" . }}
+app.kubernetes.io/instance: {{ .Release.Name }}
+{{- end }}
+
+{{/*
+Create the name of the service account to use
+*/}}
+{{- define "issue4905.serviceAccountName" -}}
+{{- if .Values.serviceAccount.create }}
+{{- default (include "issue4905.fullname" .) .Values.serviceAccount.name }}
+{{- else }}
+{{- default "default" .Values.serviceAccount.name }}
+{{- end }}
+{{- end }}

plugin/builtin/helmchartinflationgenerator/testdata/charts/issue4905/templates/configmap.yaml

@@ -0,0 +1,7 @@
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: {{ include "issue4905.fullname" . }}
+data:
+  config.yaml: |-
+    {{- .Values.config | toYaml | nindent 4 }}

plugin/builtin/helmchartinflationgenerator/testdata/charts/issue4905/values.yaml

@@ -0,0 +1 @@
+config: # null