How to handle developer translations?

I our projects we have a developer translations, that are translation written by the developer, that are late replaces by real translations made by professional translators. The translators use a demo system and periodically push new and updated translations into our repository.

But in our system test we depend on the translation and we do not want our system test to break because the translators have pushed a new wording. That is why we let our automated system test run with the developer translations.

But how should such a language tag look like for a devloper language? Tags like “de-DE” or “en-US” are used for the real translations and if we use some non exisiting tags like “de-DEV” some tools may break, because that is not a valid language Tag. For example in Java the method Local::forLanguageTag and Locale::toLanguageTag will not works with such tags. See:

package de.nilsrudolph.blog;

import org.junit.jupiter.api.Test;

import java.util.Locale;

import static org.junit.jupiter.api.Assertions.assertEquals;

public class LanguageTag {

    @Test
    public void testValidLanguageTag() {
        String validTag = "de-DE";
        assertEquals(Locale.forLanguageTag(validTag).toLanguageTag(), validTag);
    }

    @Test //This one will fail
    public void testInvalidLanguageTag() {
        String invalidTag = "de-DEV";
        assertEquals(Locale.forLanguageTag(invalidTag).toLanguageTag(), invalidTag);
    }
}

Out solution is to use a private extension. A private extension begins with the string “-x”. So that a tag for a developer language may look like “de-DE-x-dev” or “en-US-x-dev”

These tags then will work:

package de.nilsrudolph.blog;

import org.junit.jupiter.api.Test;

import java.util.Locale;

import static org.junit.jupiter.api.Assertions.assertEquals;

public class LanguageTag {

    @Test
    public void testValidLanguageTagWithPrivateExtension() {
        String validTag = "de-DE-x-dev";
        assertEquals(Locale.forLanguageTag(validTag).toLanguageTag(), validTag);
    }
}