There are various test programs under this directory.
The sub-directories contain tests about:

    api/                functions of 'idn/api.h' module.
    asclower/           IDN_ASCLOWER action.
    auto/               automatically generated source files.
    bidicheck/          IDN_BIDICHECK action.
    checkname/          idn_res_checkname() function.
    combcheck/          IDN_COMBCHECK action.
    command/            idnconv2, idncmp and idncheck commands.
    common/             (common test programs; no test case here.)
    comparenames/       idn_res_comparenames() and idn_res_comparenames2()
                        functions.
    ctxjcheck/          IDN_CTXJCHECK action.
    ctxocheck/          IDN_CTXOCHECK and IDN_CTXOLITECHECK actions.
    decodename/         idn_res_decodename() function.
    delimitermap/       'delimitermap' map procedure.
    encodename/         idn_res_encodename() function.
    hyphcheck/          IDN_HYPHCHECK action.
    idnconv/            IDN_IDNCONV action.
    language/           decision of the current language and reading
                        'idnlang.conf' file.
    languagelocal/      'language-local' map procedure and reading map files.
    lencheck/           IDN_LENCHECK action.
    libidnkitlite/      'libidnkitlite' library.
    loadconf/           idn_res_loadfile() function and reading 'idn2.conf'
                        and '.idn2rc' files.
    localcheck/         IDN_LOCALCHECK action and reading local check files.
    localconv/          IDN_LOCALCONV action.
    localencoding/      decision of the local encoding and reading
                        'idnalias.conf' file.
    lowercase/          'lowercase' map procedure.
    map/                IDN_MAP action.
    misc/               tests not performed in other directories.
    nfc/                'nfc' map procedure.
    nfccheck/           IDN_NFCCHECK action.
    nfkc/               'nfkc' map procedure.
    normalization/      normalization tests provided as a part of Unicode
                        Character Database (UCD).
    overflow/           error code 'idn_buffer_overflow'.
    prefcheck/          IDN_PREFCHECK action.
    prohcheck/          IDN_PROHCHECK action.
    result/             idn_result_tostring() function.
    rtcheck/            IDN_RTCHECK action.
    rtconv/             IDN_RTONV action.
    tldlocal/           'tld-local' map procedure and reading map files.
    tr46check/          'tr46-check' and 'tr46-check-deviation' map procedures.
    tr46map/            'tr46-map' and 'tr46-map-deviation' map procedures.
    unascheck/          IDN_UNASCHECK action.
    undoiferr/		IDN_UNDOIFERR special action.
    unicodeconv/        IDN_UNICODECONV action.
    utf8/               validation of UTF-8 string.
    version/            idn_version_getstring(), idn_version_idna(),
			idn_version_unicode() and idn_version_libidn()
			functions.
    width/              'width' map procedure.
