diff --git a/Makefile b/Makefile
index dd730e7bef..aa5970a694 100644
--- a/Makefile
+++ b/Makefile
@@ -268,6 +268,11 @@ tensorflow/install: /usr/local/lib/libtensorflow.so
 	rm -f libtensorflow-cpu-linux-x86_64-$(TENSORFLOW_C_VERSION).tar.gz
 	ldconfig
 
+.PHONY: gentest
+## gentest
+gentest:
+	$(call gen-test)
+
 .PHONY: test
 ## run tests
 test:
diff --git a/Makefile.d/functions.mk b/Makefile.d/functions.mk
index 0c818a79c1..d80b96c704 100644
--- a/Makefile.d/functions.mk
+++ b/Makefile.d/functions.mk
@@ -89,3 +89,27 @@ define telepresence
 	    ## will be available after telepresence 0.105 released
 	    ## --deployment-type "$(SWAP_DEPLOYMENT_TYPE)"
 endef
+
+define gen-test
+	find . -type d | \
+	grep "./cmd\|./hack\|./internal\|./pkg" | \
+	grep -v "./cmd/cli\| \
+			 ./hack/benchmark/internal/client/ngtd\| \
+			 ./hack/benchmark/internal/starter/agent\| \
+			 ./hack/benchmark/internal/starter/external\| \
+			 ./hack/benchmark/internal/starter/gateway\| \
+			 ./hack/license\| \
+			 ./hack/swagger\| \
+			 ./hack/tools"| \
+	while read dir; do \
+		files=`find $${dir} -type f -maxdepth 1 -name "*.go" -not -name '*_test.go' -not -name 'doc.go'`; \
+		for file in $${files}; do \
+			path='./assets/test/templates/common';     \
+			if [[ $${file} =~ .*options?\.go ]] ; then \
+				path='./assets/test/templates/option'; \
+			fi; \
+			echo start generate test code: $${file}; \
+			gotests -w -template_dir $${path} -all $${file}; \
+		done; \
+	done
+endef
diff --git a/assets/test/templates/common/call.tmpl b/assets/test/templates/common/call.tmpl
new file mode 100644
index 0000000000..92570b7e53
--- /dev/null
+++ b/assets/test/templates/common/call.tmpl
@@ -0,0 +1 @@
+{{define "call"}}{{with .Receiver}}{{if not .IsStruct}}test.{{end}}{{Receiver .}}.{{end}}{{.Name}}({{range $i, $el := .Parameters}}{{if $i}}, {{end}}{{if not .IsWriter}}test.args.{{end}}{{Param .}}{{if .Type.IsVariadic}}...{{end}}{{end}}){{end}}
diff --git a/assets/test/templates/common/fill.tmpl b/assets/test/templates/common/fill.tmpl
new file mode 100644
index 0000000000..25d82c4677
--- /dev/null
+++ b/assets/test/templates/common/fill.tmpl
@@ -0,0 +1,28 @@
+{{define "fill" }}
+        {{- range . }}
+                {{ Param . }}: {{ $typ := .Type.String -}}
+                {{- if eq $typ "int8" -}} 0,
+                {{- else if eq $typ "uint8" -}} 0,
+                {{- else if eq $typ "uint16" -}} 0,
+                {{- else if eq $typ "uint32" -}} 0,
+                {{- else if eq $typ "uint64" -}} 0,
+                {{- else if eq $typ "uint" -}} 0,
+                {{- else if eq $typ "uintptr" -}} 0,
+                {{- else if eq $typ "int8" -}} 0,
+                {{- else if eq $typ "int16" -}} 0,
+                {{- else if eq $typ "int32" -}} 0,
+                {{- else if eq $typ "int64" -}} 0,
+                {{- else if eq $typ "int" -}} 0,
+                {{- else if eq $typ "float32" -}} 0,
+                {{- else if eq $typ "float64" -}} 0,
+                {{- else if eq $typ "complex64" -}} 0+0i,
+                {{- else if eq $typ "complex128" -}} 0+0i,
+                {{- else if eq $typ "byte" -}} 0,
+                {{- else if eq $typ "rune" -}} 0,
+                {{- else if eq $typ "string" -}} "",
+                {{- else if eq $typ "bool" -}} false,
+                {{- else if .IsStruct -}} {{.Type.Value}}{},
+                {{- else -}} nil,
+                {{- end -}}
+        {{ end -}}
+{{ end }}
diff --git a/assets/test/templates/common/function.tmpl b/assets/test/templates/common/function.tmpl
new file mode 100644
index 0000000000..5f78b37d85
--- /dev/null
+++ b/assets/test/templates/common/function.tmpl
@@ -0,0 +1,154 @@
+{{define "function"}}
+{{- $f := . }}
+
+func {{ .TestName }}(t *testing.T) {
+    {{- if .TestParameters }}
+    type args struct {
+		{{- range .TestParameters }}
+				{{ Param . }} {{ .Type }}
+		{{- end}}
+    }
+    {{- end }}
+    {{- $hasFields := false -}}
+    {{- with .Receiver }}
+        {{- if .IsStruct }}
+            {{- if .Fields}}
+                type fields struct { {{ $hasFields = true }}
+                    {{- range .Fields }}
+                        {{ Field . }} {{ .Type }}
+                    {{- end }}
+                }
+            {{- end }}
+        {{- end }}
+    {{- end }}
+    type want struct {
+        {{- range .TestResults }}
+            {{ Want . }} {{ .Type }}
+        {{- end }}
+        {{- if .ReturnsError }}
+            err error
+        {{- end }}
+    }
+    type test struct {
+        name string
+        {{- if .TestParameters }}
+            args args
+        {{- end }}
+        {{- with .Receiver}}
+            {{- if and .IsStruct .Fields}}
+                fields fields
+            {{- else}}
+                {{Receiver .}} {{.Type}}
+            {{- end}}
+        {{- end}}
+        want want
+        checkFunc func(want,
+                    {{- range .TestResults }} {{ .Type }}, {{- end }}
+                    {{- if .ReturnsError }} error {{- end }} ) error
+        beforeFunc func({{- if .TestParameters }} args {{- end}})
+        afterFunc func({{- if .TestParameters }} args {{- end}})
+    }
+    defaultCheckFunc := func(w want,
+        {{- range .TestResults }} {{ Got . }} {{ .Type }}, {{- end }}
+        {{- if .ReturnsError }} err error {{- end }} ) error {
+
+        {{- if .ReturnsError }}
+            if !errors.Is(err, w.err) {
+                return errors.Errorf("got error = %v, want %v", err, w.err)
+            }
+        {{- end }}
+        {{- range .TestResults }} {{ $want := Want . }} {{ $got := Got . }}
+            if !reflect.DeepEqual({{ $got }}, w.{{ $want }}) {
+                return errors.Errorf("got = %v, want %v", {{ $got }}, w.{{ $want }})
+            }
+        {{- end }}
+        return nil
+    }
+    tests := []test{
+        // TODO test cases
+        /*
+        {
+            name: "test_case_1",
+            {{- if .TestParameters }}
+            args: args {
+                {{- template "fill" .TestParameters }}
+            },
+            {{- end }}
+            {{- if $hasFields }}
+            fields: fields {
+                {{- template "fill" .Receiver.Fields }}
+            },
+            {{- end }}
+            want: want{},
+            checkFunc: defaultCheckFunc,
+        },
+        */
+
+        // TODO test cases
+        /*
+        func() test {
+            return test {
+                name: "test_case_2",
+                {{- if .TestParameters }}
+                args: args {
+                    {{- template "fill" .TestParameters }}
+                },
+                {{- end }}
+                {{- if $hasFields }}
+                fields: fields {
+                    {{- template "fill" .Receiver.Fields }}
+                },
+                {{- end }}
+                want: want{},
+                checkFunc: defaultCheckFunc,
+            }
+        }(),
+        */
+    }
+
+    for {{- if (or .Subtests (not .IsNaked)) }} _, test := {{- end }} range tests {
+        {{- if .Subtests }}
+            t.Run(test.name, func(tt *testing.T) {
+                if test.beforeFunc != nil {
+                    test.beforeFunc({{- if .TestParameters }} test.args {{- end }})
+                }
+                if test.afterFunc != nil {
+                    defer test.afterFunc({{- if .TestParameters }} test.args {{- end }})
+                }
+                if test.checkFunc == nil {
+                    test.checkFunc = defaultCheckFunc
+                }
+
+                {{- with .Receiver }}
+                    {{- if .IsStruct }}
+                        {{ Receiver . }} := {{- if .Type.IsStar }}&{{- end }}{{ .Type.Value }} {
+                        {{- range .Fields }}
+                            {{ Field . }}: test.fields.{{ Field . }},
+                        {{- end }}
+                        }
+                    {{- end }}
+                {{- end }}
+
+                {{- range .Parameters }}
+                    {{- if .IsWriter }}
+                        {{ Param . }} := &bytes.Buffer{}
+                    {{- end }}
+                {{- end }}
+
+                {{ $len := len .Results }}
+                {{- if or (ge $len 1) (.OnlyReturnsOneValue) (.OnlyReturnsError) }}
+                    {{ template "results" $f }} := {{ template "call" $f }}
+                    if err := test.checkFunc(test.want, {{ template "results" $f }} ); err != nil {
+                        tt.Errorf("error = %v", err)
+                    }
+                {{ else }}
+                    {{ template "call" $f }}
+                    if err := test.checkFunc(test.want); err != nil {
+                        tt.Errorf("error = %v", err)
+                    }
+                {{- end }}
+            })
+        {{- end }}
+    }
+}
+{{- end }}
diff --git a/assets/test/templates/common/header.tmpl b/assets/test/templates/common/header.tmpl
new file mode 100644
index 0000000000..245569df7e
--- /dev/null
+++ b/assets/test/templates/common/header.tmpl
@@ -0,0 +1,10 @@
+{{define "header"}}
+{{range .Comments}}{{.}}
+{{end -}}
+package {{.Package}}
+
+import (
+{{range .Imports}}{{.Name}} {{.Path}}
+{{end}}
+)
+{{end}}
diff --git a/assets/test/templates/common/inline.tmpl b/assets/test/templates/common/inline.tmpl
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/assets/test/templates/common/inputs.tmpl b/assets/test/templates/common/inputs.tmpl
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/assets/test/templates/common/message.tmpl b/assets/test/templates/common/message.tmpl
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/assets/test/templates/common/results.tmpl b/assets/test/templates/common/results.tmpl
new file mode 100644
index 0000000000..8b94e3d558
--- /dev/null
+++ b/assets/test/templates/common/results.tmpl
@@ -0,0 +1,2 @@
+{{define "results"}}{{- if .OnlyReturnsError }}err{{ else }}{{range $i, $el := .Results}}{{if $i}}, {{end}}{{Got .}}{{end}}{{if .ReturnsError}}, err{{end}}
+{{- end }}{{end}}
diff --git a/assets/test/templates/option/call.tmpl b/assets/test/templates/option/call.tmpl
new file mode 120000
index 0000000000..9ebd7e2d8a
--- /dev/null
+++ b/assets/test/templates/option/call.tmpl
@@ -0,0 +1 @@
+../common/call.tmpl
\ No newline at end of file
diff --git a/assets/test/templates/option/fill.tmpl b/assets/test/templates/option/fill.tmpl
new file mode 120000
index 0000000000..873307f910
--- /dev/null
+++ b/assets/test/templates/option/fill.tmpl
@@ -0,0 +1 @@
+../common/fill.tmpl
\ No newline at end of file
diff --git a/assets/test/templates/option/function.tmpl b/assets/test/templates/option/function.tmpl
new file mode 100644
index 0000000000..67a60d9647
--- /dev/null
+++ b/assets/test/templates/option/function.tmpl
@@ -0,0 +1,156 @@
+{{define "function"}}
+{{- $f := . }}
+
+func {{ .TestName }}(t *testing.T) {
+    type T = interface{}
+    {{- if .TestParameters }}
+    type args struct {
+        {{- range .TestParameters }}
+            {{ Param . }} {{ .Type }}
+        {{- end}}
+    }
+    {{- end }}
+    {{- $hasFields := false -}}
+    {{- with .Receiver }}
+        {{- if .IsStruct }}
+            {{- if .Fields}}
+                type fields struct { {{ $hasFields = true }}
+                    {{- range .Fields }}
+                        {{ Field . }} {{ .Type }}
+                    {{- end }}
+                }
+            {{- end }}
+        {{- end }}
+    {{- end }}
+    type want struct {
+        obj *T
+        // Uncomment this line if the option returns an error, otherwise delete it
+        // err error
+    }
+    type test struct {
+        name string
+        {{- if .TestParameters }}
+            args args
+        {{- end }}
+        {{- with .Receiver}}
+            {{- if and .IsStruct .Fields}}
+                fields fields
+            {{- else}}
+                {{Receiver .}} {{.Type}}
+            {{- end}}
+        {{- end}}
+        want want
+        // Use the first line if the option returns an error. otherwise use the second line
+        // checkFunc  func(want, *T, error) error
+        // checkFunc  func(want, *T) error
+        beforeFunc func({{- if .TestParameters }} args {{- end}})
+        afterFunc func({{- if .TestParameters }} args {{- end}})
+    }
+
+    // Uncomment this block if the option returns an error, otherwise delete it
+    /*
+    defaultCheckFunc := func(w want, obj *T, err error) error {
+        if !errors.Is(err, w.err) {
+            return errors.Errorf("got error = %v, want %v", err, w.err)
+        }
+        if !reflect.DeepEqual(obj, w.obj) {
+            return errors.Errorf("got = %v, want %v", obj, w.obj)
+        }
+        return nil
+    }
+    */
+
+    // Uncomment this block if the option do not returns an error, otherwise delete it
+    /*
+    defaultCheckFunc := func(w want, obj *T) error {
+        if !reflect.DeepEqual(obj, w.obj) {
+            return fmt.Errorf("got = %v, want %v", obj, w.c)
+        }
+        return nil
+    }
+    */
+
+    tests := []test{
+        // TODO test cases
+        /*
+        {
+            name: "test_case_1",
+            {{- if .TestParameters }}
+            args: args {
+                {{- template "fill" .TestParameters }}
+            },
+            {{- end }}
+            {{- if $hasFields }}
+            fields: fields {
+                {{- template "fill" .Receiver.Fields }}
+            },
+            {{- end }}
+            want: want {
+                obj: new(T),
+            },
+        },
+        */
+
+        // TODO test cases
+        /*
+        func() test {
+            return test {
+                name: "test_case_2",
+                {{- if .TestParameters }}
+                args: args {
+                    {{- template "fill" .TestParameters }}
+                },
+                {{- end }}
+                {{- if $hasFields }}
+                fields: fields {
+                    {{- template "fill" .Receiver.Fields }}
+                },
+                {{- end }}
+                want: want {
+                    obj: new(T),
+                },
+            }
+        }(),
+        */
+    }
+
+    for {{- if (or .Subtests (not .IsNaked)) }} _, test := {{- end }} range tests {
+        {{- if .Subtests }}
+            t.Run(test.name, func(tt *testing.T) {
+                if test.beforeFunc != nil {
+                    test.beforeFunc({{- if .TestParameters }} test.args {{- end }})
+                }
+                if test.afterFunc != nil {
+                    defer test.afterFunc({{- if .TestParameters }} test.args {{- end }})
+                }
+
+                // Uncomment this block if the option returns an error, otherwise delete it
+                /*
+                if test.checkFunc == nil {
+                    test.checkFunc = defaultCheckFunc
+                }
+
+                got := {{ template "call" $f }}
+                obj := new(T)
+                if err := test.checkFunc(test.want, obj, got(obj)); err != nil {
+                    tt.Errorf("error = %v", err)
+                }
+                */
+
+                // Uncomment this block if the option returns an error, otherwise delete it
+                /*
+                if test.checkFunc == nil {
+                    test.checkFunc = defaultCheckFunc
+                }
+                got := {{ template "call" $f }}
+                obj := new(T)
+                got(obj)
+                if err := test.checkFunc(tt.want, obj); err != nil {
+                    tt.Errorf("error = %v", err)
+                }
+                */
+            })
+        {{- end }}
+    }
+}
+{{- end }}
diff --git a/assets/test/templates/option/header.tmpl b/assets/test/templates/option/header.tmpl
new file mode 120000
index 0000000000..1b01327e84
--- /dev/null
+++ b/assets/test/templates/option/header.tmpl
@@ -0,0 +1 @@
+../common/header.tmpl
\ No newline at end of file
diff --git a/assets/test/templates/option/inline.tmpl b/assets/test/templates/option/inline.tmpl
new file mode 120000
index 0000000000..20800f829f
--- /dev/null
+++ b/assets/test/templates/option/inline.tmpl
@@ -0,0 +1 @@
+../common/inline.tmpl
\ No newline at end of file
diff --git a/assets/test/templates/option/inputs.tmpl b/assets/test/templates/option/inputs.tmpl
new file mode 120000
index 0000000000..2e62eb5e25
--- /dev/null
+++ b/assets/test/templates/option/inputs.tmpl
@@ -0,0 +1 @@
+../common/inputs.tmpl
\ No newline at end of file
diff --git a/assets/test/templates/option/message.tmpl b/assets/test/templates/option/message.tmpl
new file mode 120000
index 0000000000..8fabb08f36
--- /dev/null
+++ b/assets/test/templates/option/message.tmpl
@@ -0,0 +1 @@
+../common/message.tmpl
\ No newline at end of file
diff --git a/assets/test/templates/option/results.tmpl b/assets/test/templates/option/results.tmpl
new file mode 120000
index 0000000000..c8010be6e9
--- /dev/null
+++ b/assets/test/templates/option/results.tmpl
@@ -0,0 +1 @@
+../common/results.tmpl
\ No newline at end of file
diff --git a/go.mod b/go.mod
index 74c999f944..a0be38ef1b 100755
--- a/go.mod
+++ b/go.mod
@@ -51,7 +51,7 @@ require (
 	go.opencensus.io v0.22.3
 	go.uber.org/automaxprocs v1.3.0
 	golang.org/x/sys v0.0.0-20191128015809-6d18c012aee9
-	golang.org/x/tools v0.0.0-20200421144719-26dd2a56eb2c // indirect
+	golang.org/x/tools v0.0.0-20200423205358-59e73619c742 // indirect
 	gonum.org/v1/hdf5 v0.0.0-20191105085658-fe04b73f3b53
 	gonum.org/v1/plot v0.7.0
 	google.golang.org/genproto v0.0.0-20200420144010-e5e8543f8aeb
diff --git a/go.sum b/go.sum
index 39cb45a8fa..16e2cf909e 100644
--- a/go.sum
+++ b/go.sum
@@ -595,6 +595,8 @@ golang.org/x/tools v0.0.0-20200421042724-cfa8b22178d2 h1:fVXd7Kf16vo/CTZCrBFb6Be
 golang.org/x/tools v0.0.0-20200421042724-cfa8b22178d2/go.mod h1:EkVYQZoAsY45+roYkvgYkIh4xh/qjgUK9TdY2XT94GE=
 golang.org/x/tools v0.0.0-20200421144719-26dd2a56eb2c h1:DS5GY1XpuL4qXOy43NhcD9dUmBHezAABwfQ105ojI08=
 golang.org/x/tools v0.0.0-20200421144719-26dd2a56eb2c/go.mod h1:EkVYQZoAsY45+roYkvgYkIh4xh/qjgUK9TdY2XT94GE=
+golang.org/x/tools v0.0.0-20200423205358-59e73619c742 h1:9OGWpORUXvk8AsaBJlpzzDx7Srv/rSK6rvjcsJq4rJo=
+golang.org/x/tools v0.0.0-20200423205358-59e73619c742/go.mod h1:EkVYQZoAsY45+roYkvgYkIh4xh/qjgUK9TdY2XT94GE=
 golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543 h1:E7g+9GITq07hpfrRu66IVDexMakfv52eLZ2CXBWiKr4=
diff --git a/hack/license/gen/main.go b/hack/license/gen/main.go
index cf24f669d6..f0f0cda937 100644
--- a/hack/license/gen/main.go
+++ b/hack/license/gen/main.go
@@ -114,6 +114,7 @@ func dirwalk(dir string) []string {
 			".sum",
 			".svg",
 			".tpl",
+			".tmpl",
 			".txt",
 			".whitesource",
 			"LICENSE",
diff --git a/k8s/agent/statefulset.yaml b/k8s/agent/statefulset.yaml
index db67d8e094..c866d02380 100644
--- a/k8s/agent/statefulset.yaml
+++ b/k8s/agent/statefulset.yaml
@@ -55,10 +55,10 @@ spec:
             - podAffinityTerm:
                 labelSelector:
                   matchExpressions:
-                  - key: app
-                    operator: In
-                    values:
-                    - vald-agent-ngt
+                    - key: app
+                      operator: In
+                      values:
+                        - vald-agent-ngt
                 topologyKey: kubernetes.io/hostname
               weight: 100
           requiredDuringSchedulingIgnoredDuringExecution: []
diff --git a/k8s/discoverer/deployment.yaml b/k8s/discoverer/deployment.yaml
index 3f9826e160..d267b5696a 100644
--- a/k8s/discoverer/deployment.yaml
+++ b/k8s/discoverer/deployment.yaml
@@ -54,10 +54,10 @@ spec:
             - podAffinityTerm:
                 labelSelector:
                   matchExpressions:
-                  - key: app
-                    operator: In
-                    values:
-                    - vald-discoverer
+                    - key: app
+                      operator: In
+                      values:
+                        - vald-discoverer
                 topologyKey: kubernetes.io/hostname
               weight: 100
           requiredDuringSchedulingIgnoredDuringExecution: []
diff --git a/k8s/gateway/vald/deployment.yaml b/k8s/gateway/vald/deployment.yaml
index e70ed08a0d..8ffb98482a 100644
--- a/k8s/gateway/vald/deployment.yaml
+++ b/k8s/gateway/vald/deployment.yaml
@@ -98,10 +98,10 @@ spec:
             - podAffinityTerm:
                 labelSelector:
                   matchExpressions:
-                  - key: app
-                    operator: In
-                    values:
-                    - vald-gateway
+                    - key: app
+                      operator: In
+                      values:
+                        - vald-gateway
                 topologyKey: kubernetes.io/hostname
               weight: 100
           requiredDuringSchedulingIgnoredDuringExecution: []
diff --git a/k8s/operator/helm/valdrelease.yaml b/k8s/operator/helm/valdrelease.yaml
index 61901c60b3..79efc89b8f 100644
--- a/k8s/operator/helm/valdrelease.yaml
+++ b/k8s/operator/helm/valdrelease.yaml
@@ -20,5 +20,4 @@ metadata:
   name: vald-cluster
   namespace: default
 # the values of Helm chart for Vald can be placed under the `spec` field.
-spec:
-  {}
+spec: {}