Function tplFun

pkg/engine/helm/engine.go:156–201

As does 'tpl', so that nested calls to 'tpl' see the templates defined by their enclosing contexts.

(parent *template.Template, includedNames map[string]int, strict bool)

// As does 'tpl', so that nested calls to 'tpl' see the templates
// defined by their enclosing contexts.
func tplFun(parent *template.Template, includedNames map[string]int, strict bool) func(string, any) (string, error) {
	return func(tpl string, vals any) (string, error) {
		tmpl, err := parent.Clone()
		if err != nil {
			return "", errors.Wrapf(err, "cannot clone template")
		}

		// Re-inject the missingkey option, see text/template issue https://github.com/golang/go/issues/43022
		// We have to go by strict from our engine configuration, as the option fields are private in Template.
		//nolint:godox // upstream Helm tracks a Go stdlib workaround; comment is intentional.
		// TODO: Remove workaround (and the strict parameter) once we build only with golang versions with a fix.
		if strict {
			tmpl.Option("missingkey=error")
		} else {
			tmpl.Option("missingkey=zero")
		}

		// Re-inject 'include' so that it can close over our clone of tmpl;
		// this lets any 'define's inside tpl be 'include'd.
		tmpl.Funcs(template.FuncMap{
			helmFuncInclude: includeFun(tmpl, includedNames),
			helmFuncTpl:     tplFun(tmpl, includedNames, strict),
		})

		// We need a .New template, as template text which is just blanks
		// or comments after parsing out defines just addes new named
		// template definitions without changing the main template.
		// https://pkg.go.dev/text/template#Template.Parse
		// Use the parent's name for lack of a better way to identify the tpl
		// text string. (Maybe we could use a hash appended to the name?)
		tmpl, err = tmpl.New(parent.Name()).Parse(tpl)
		if err != nil {
			return "", errors.Wrapf(err, "cannot parse template %q", tpl)
		}

		var buf strings.Builder

		err = tmpl.Execute(&buf, vals)
		if err != nil {
			return "", errors.Wrapf(err, "error during tpl function execution for %q", tpl)
		}

		// See comment in renderWithReferences explaining the <no value> hack.
		return strings.ReplaceAll(buf.String(), "<no value>", ""), nil
	}
}

// initFunMap creates the Engine's FuncMap and adds context-specific functions.
func (e Engine) initFunMap(tmpl *template.Template) {