fix: Keep backward-compatibility broken after introduction of values file template (#257)

Fixes #249

valuesfile/valuesfile.go

@@ -0,0 +1,39 @@
+package valuesfile
+
+import (
+	"fmt"
+	"github.com/roboll/helmfile/tmpl"
+	"strings"
+)
+
+type renderer struct {
+	readFile         func(string) ([]byte, error)
+	tmplFileRenderer tmpl.FileRenderer
+}
+
+func NewRenderer(readFile func(filename string) ([]byte, error)) *renderer {
+	return &renderer{
+		readFile:         readFile,
+		tmplFileRenderer: tmpl.NewFileRenderer(readFile),
+	}
+}
+
+func (r *renderer) RenderToBytes(path string) ([]byte, error) {
+	var yamlBytes []byte
+	splits := strings.Split(path, ".")
+	if len(splits) > 0 && splits[len(splits)-1] == "gotmpl" {
+		yamlBuf, err := r.tmplFileRenderer.RenderTemplateFileToBuffer(path)
+		if err != nil {
+
+			return nil, fmt.Errorf("failed to render [%s], because of %v", path, err)
+		}
+		yamlBytes = yamlBuf.Bytes()
+	} else {
+		var err error
+		yamlBytes, err = r.readFile(path)
+		if err != nil {
+			return nil, fmt.Errorf("failed to load [%s]: %v", path, err)
+		}
+	}
+	return yamlBytes, nil
+}

valuesfile/valuesfile_test.go

@@ -0,0 +1,61 @@
+package valuesfile
+
+import (
+	"fmt"
+	"reflect"
+	"testing"
+)
+
+func TestRenderToBytes_Gotmpl(t *testing.T) {
+	valuesYamlTmplContent := `foo:
+  bar: '{{ readFile "data.txt" }}'
+`
+	dataFileContent := "FOO_BAR"
+	expected := `foo:
+  bar: 'FOO_BAR'
+`
+	dataFile := "data.txt"
+	valuesTmplFile := "values.yaml.gotmpl"
+	r := NewRenderer(func(filename string) ([]byte, error) {
+		switch filename {
+		case valuesTmplFile:
+			return []byte(valuesYamlTmplContent), nil
+		case dataFile:
+			return []byte(dataFileContent), nil
+		}
+		return nil, fmt.Errorf("unexpected filename: expected=%v or %v, actual=%s", dataFile, valuesTmplFile, filename)
+	})
+	buf, err := r.RenderToBytes(valuesTmplFile)
+	if err != nil {
+		t.Errorf("unexpected error: %v", err)
+	}
+	actual := string(buf)
+	if !reflect.DeepEqual(actual, expected) {
+		t.Errorf("unexpected result: expected=%v, actual=%v", expected, actual)
+	}
+}
+
+func TestRenderToBytes_Yaml(t *testing.T) {
+	valuesYamlContent := `foo:
+  bar: '{{ readFile "data.txt" }}'
+`
+	expected := `foo:
+  bar: '{{ readFile "data.txt" }}'
+`
+	valuesFile := "values.yaml"
+	r := NewRenderer(func(filename string) ([]byte, error) {
+		switch filename {
+		case valuesFile:
+			return []byte(valuesYamlContent), nil
+		}
+		return nil, fmt.Errorf("unexpected filename: expected=%v, actual=%s", valuesFile, filename)
+	})
+	buf, err := r.RenderToBytes(valuesFile)
+	if err != nil {
+		t.Errorf("unexpected error: %v", err)
+	}
+	actual := string(buf)
+	if !reflect.DeepEqual(actual, expected) {
+		t.Errorf("unexpected result: expected=%v, actual=%v", expected, actual)
+	}
+}