chore: tidy up pkgs (#636)

for readability and towards potentially making helmfile usable as a go library

pkg/tmpl/file_renderer_test.go

@@ -0,0 +1,67 @@
+package tmpl
+
+import (
+	"fmt"
+	"github.com/roboll/helmfile/pkg/environment"
+	"reflect"
+	"testing"
+)
+
+var emptyEnvTmplData = map[string]interface{}{
+	"Environment": environment.EmptyEnvironment,
+	"Namespace":   "",
+}
+
+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 := NewFileRenderer(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)
+	}, "", emptyEnvTmplData)
+	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 := NewFileRenderer(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)
+	}, "", emptyEnvTmplData)
+	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)
+	}
+}