2020-11-04: 'make check' does not catch entries with no body about glosario HOT 1 OPEN

- slug:           # nothing here


- slug: an_entry

- slug: entry
    unknown_key:

- slug: entry

-                  # missing the slug key

- slug: another_entry

def checkEntry(entry):
    ''' 
    Check structure of individual entries, returning a language-to-set
    dictionary of terms references in the body.
    '''
    keys = set(entry.keys())

** ENTRY_REQUIRED_KEYS is {'slug'} (won't be missing for an entry without a body) **
    missing = [k for k in ENTRY_REQUIRED_KEYS if k not in keys]               
    if missing:
        print(f'Missing required keys for entry {entry}: {missing}')
    slug = entry['slug']
    unknown_keys = keys - ENTRY_KEYS
    if unknown_keys:
        print(f'Unknown keys in {slug}: {unknown_keys}')
    result = {}
    crossrefs = set(entry['ref']) if ('ref' in entry) else set()

** if the entry is empty, it doesn't have any language keys, so it is silently dropped here **
    for lang in ENTRY_LANGUAGE_KEYS:
        if lang in entry:
            label = f'{slug}/{lang}'
            result[lang] = checkLanguageDef(label, crossrefs, entry[lang])
    return result