Function reformatExecErrorMsg

pkg/engine/engine.go:452–495

reformatExecErrorMsg takes an error message for template rendering and formats it into a formatted multi-line error string

(filename string, err error)

// reformatExecErrorMsg takes an error message for template rendering and formats it into a formatted
// multi-line error string
func reformatExecErrorMsg(filename string, err error) error {
	// This function parses the error message produced by text/template package.
	// If it can parse out details from that error message such as the line number, template it failed on,
	// and error description, then it will construct a new error that displays these details in a structured way.
	// If there are issues with parsing the error message, the err passed into the function should return instead.
	var execError template.ExecError
	if !errors.As(err, &execError) {
		return err
	}

	tokens := strings.SplitN(err.Error(), ": ", 3)
	if len(tokens) != 3 {
		// This might happen if a non-templating error occurs
		return fmt.Errorf("execution error in (%s): %w", filename, err)
	}

	// The first token is "template"
	// The second token is either "filename:lineno" or "filename:lineNo:columnNo"
	location := tokens[1]

	parts := warnRegex.FindStringSubmatch(tokens[2])
	if len(parts) >= 2 {
		return fmt.Errorf("execution error at (%s): %s", location, parts[1])
	}
	current := err
	var fileLocations []TraceableError
	for current != nil {
		if tr, ok := parseTemplateExecErrorString(current.Error()); ok {
			if len(fileLocations) == 0 || fileLocations[len(fileLocations)-1] != tr {
				fileLocations = append(fileLocations, tr)
			}
		} else {
			return err
		}
		current = errors.Unwrap(current)
	}

	var finalErrorString strings.Builder
	for _, fileLocation := range fileLocations {
		_, _ = fmt.Fprintf(&finalErrorString, "%s", fileLocation.String())
	}

	return errors.New(strings.TrimSpace(finalErrorString.String()))
}

func sortTemplates(tpls map[string]renderable) []string {
	keys := make([]string, len(tpls))