add cloudinit.Generate test

pkg/cloudinit/generator.go

@@ -2,7 +2,6 @@ package cloudinit
 
 import (
 	"bytes"
-	"fmt"
 	"text/template"
 
 	"github.com/goccy/go-yaml"
@@ -26,17 +25,18 @@ func Generate(c Config, vars map[string]string) (string, error) {
 		return "", err
 	}
 
-	temp, err := template.New("cloud-config").Parse(buff.String())
+	temp, err := template.New("cloud-config").Parse(`#cloud-config
+package_update: true
+
+` + buff.String())
 	if err != nil {
 		return "", err
 	}
 
-	if err := temp.Execute(buff, vars); err != nil {
+	output := &bytes.Buffer{}
+	if err := temp.Execute(output, vars); err != nil {
 		return "", err
 	}
 
-	return fmt.Sprintf(`#cloud-config
-package_update: true
-
-%s`, buff.String()), nil
+	return output.String(), nil
 }

pkg/cloudinit/generator_test.go

@@ -0,0 +1,52 @@
+package cloudinit_test
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+
+	"github.com/ryota-sakamoto/kubernetes-on-multipass/pkg/cloudinit"
+)
+
+func TestGenerate(t *testing.T) {
+	result, err := cloudinit.Generate(cloudinit.Config{
+		Packages: []string{
+			"git",
+			"vim",
+		},
+		WriteFiles: []cloudinit.WriteFile{
+			{
+				Content: `file {{ .Content }}`,
+				Path:    "/opt/ok",
+			},
+			{
+				Content:     `echo ok`,
+				Path:        "/use/bin/ok",
+				Permissions: "0755",
+			},
+		},
+		RunCmds: []string{
+			"/use/bin/ok",
+		},
+	}, map[string]string{
+		"Content": "content",
+	})
+	assert.NoError(t, err)
+
+	expectedResult := `#cloud-config
+package_update: true
+
+packages:
+- git
+- vim
+write_files:
+- path: /opt/ok
+  content: file content
+- path: /use/bin/ok
+  content: echo ok
+  permissions: "0755"
+runcmd:
+- /use/bin/ok
+`
+	assert.Equal(t, expectedResult, result)
+}