How to use the fava.serialisation.serialise function in fava

def test_serialise_posting(amount_cost_price, amount_string):
    pos = Posting("Assets", *amount_cost_price, None, None)
    json = {"account": "Assets", "amount": amount_string}
    assert loads(dumps(serialise(pos))) == json
    assert deserialise_posting(json) == pos

{"account": "Assets:ETrade:Cash", "amount": "100 USD"},
            {"account": "Assets:ETrade:GLD", "amount": ""},
        ],
    }

    with app.test_request_context():
        serialised = loads(dumps(serialise(txn)))
        assert serialised == json_txn

        txn = txn._replace(payee="")
        json_txn["payee"] = ""
        serialised = loads(dumps(serialise(txn)))
        assert serialised == json_txn

        txn = txn._replace(payee=None)
        serialised = loads(dumps(serialise(txn)))
        assert serialised == json_txn

def test_serialise(app):
    assert serialise(None) is None
    txn = Transaction(
        {},
        datetime.date(2017, 12, 12),
        "*",
        "Test3",
        "asdfasd",
        frozenset(["tag"]),
        frozenset(["link"]),
        [],
    )
    create_simple_posting(txn, "Assets:ETrade:Cash", "100", "USD")
    create_simple_posting(txn, "Assets:ETrade:GLD", None, None)

    json_txn = {
        "date": "2017-12-12",
        "flag": "*",

None,
        None,
    )

    json = {
        "date": "2019-09-17",
        "amount": {"currency": "CHF", "number": "0.1234567891011121314151617"},
        "diff_amount": None,
        "meta": {},
        "tolerance": None,
        "account": "Assets:ETrade:Cash",
        "type": "Balance",
    }

    with app.test_request_context():
        serialised = loads(dumps(serialise(bal)))

    assert serialised == json

json_txn = {
        "date": "2017-12-12",
        "flag": "*",
        "meta": {},
        "narration": "asdfasd #tag ^link",
        "payee": "Test3",
        "type": "Transaction",
        "postings": [
            {"account": "Assets:ETrade:Cash", "amount": "100 USD"},
            {"account": "Assets:ETrade:GLD", "amount": ""},
        ],
    }

    with app.test_request_context():
        serialised = loads(dumps(serialise(txn)))
        assert serialised == json_txn

        txn = txn._replace(payee="")
        json_txn["payee"] = ""
        serialised = loads(dumps(serialise(txn)))
        assert serialised == json_txn

        txn = txn._replace(payee=None)
        serialised = loads(dumps(serialise(txn)))
        assert serialised == json_txn

@BABEL.localeselector
def get_locale():
    """Get locale.

    Returns:
        The locale that should be used for Babel. If not given as an option to
        Fava, guess from browser.
    """
    if g.ledger.fava_options["language"]:
        return g.ledger.fava_options["language"]
    return request.accept_languages.best_match(["en"] + LANGUAGES)


for _, function in inspect.getmembers(template_filters, inspect.isfunction):
    app.add_template_filter(function)
app.add_template_filter(serialise)


@app.url_defaults
def _inject_filters(endpoint, values):
    if "bfile" not in values and app.url_map.is_endpoint_expecting(
        endpoint, "bfile"
    ):
        values["bfile"] = g.beancount_file_slug
    if endpoint in ["static", "index"]:
        return
    if "interval" not in values:
        values["interval"] = request.args.get("interval")
    if "conversion" not in values:
        values["conversion"] = request.args.get("conversion")
    for filter_name in ["account", "filter", "time"]:
        if filter_name not in values:

def extract():
    """Extract entries using the ingest framework."""
    entries = g.ledger.ingest.extract(
        request.args.get("filename"), request.args.get("importer")
    )
    return list(map(serialise, entries))

def payee_transaction():
    """Last transaction for the given payee."""
    entry = g.ledger.attributes.payee_transaction(request.args.get("payee"))
    return serialise(entry)