historical: Add main code for historical subcommand.

oxrlib/commands/historical.py

@@ -0,0 +1,25 @@
+import oxrlib.rate
+
+def format_one_rate(rate, from_amt, from_curr, to_curr):
+    return "{:g} {} = {:g} {}".format(
+        from_amt, from_curr, rate.convert(from_amt, from_curr, to_curr), to_curr)
+
+def format_rate_pair(rate, from_curr, to_curr):
+    yield format_one_rate(rate, 1, from_curr, to_curr)
+    yield format_one_rate(rate, 1, to_curr, from_curr)
+
+def run(config, stdout, stderr):
+    loaders = config.get_loaders()
+    with loaders.historical(config.args.date, config.args.base) as rate_json:
+        rate = oxrlib.rate.Rate.from_json_file(rate_json)
+    if not config.args.from_currency:
+        for from_curr in sorted(rate.rates):
+            print(*format_rate_pair(rate, from_curr, config.args.to_currency),
+                  sep='\n', file=stdout)
+    elif config.args.amount is None:
+        print(*format_rate_pair(rate, config.args.from_currency, config.args.to_currency),
+              sep='\n', file=stdout)
+    else:
+        print(format_one_rate(rate, config.args.amount,
+                              config.args.from_currency, config.args.to_currency),
+              file=stdout)

tests/test_historical.py

@@ -0,0 +1,92 @@
+import argparse
+import decimal
+import io
+import json
+
+import pytest
+
+from . import any_date, relpath
+
+import oxrlib.commands.historical as oxrhist
+
+class FakeResponder:
+    def __init__(self, response_path):
+        self.response_path = response_path
+
+    def _respond(self, *args, **kwargs):
+        return open(self.response_path)
+
+    def __getattr__(self, name):
+        return self._respond
+
+
+class FakeConfig:
+    def __init__(self, responder, argvars=None):
+        self.responder = responder
+        self.args = argparse.Namespace()
+        if argvars is not None:
+            for key in argvars:
+                setattr(self.args, key, argvars[key])
+
+    def get_loaders(self):
+        return self.responder
+
+
+output = pytest.fixture(lambda: io.StringIO())
+
+@pytest.fixture
+def historical1_responder():
+    return FakeResponder(relpath('historical1.json').as_posix())
+
+def build_config(
+        responder,
+        date=None,
+        amount=None,
+        from_currency=None,
+        to_currency=None,
+        base='USD',
+):
+    return FakeConfig(responder, {
+        'date': any_date() if date is None else date,
+        'base': base,
+        'amount': None if amount is None else decimal.Decimal(amount),
+        'from_currency': from_currency,
+        'to_currency': base if to_currency is None else to_currency,
+    })
+
+def lines_from_run(config, output):
+    oxrhist.run(config, output, output)
+    output.seek(0)
+    return iter(output)
+
+def test_rate_list(historical1_responder, output):
+    config = build_config(historical1_responder)
+    lines = lines_from_run(config, output)
+    assert next(lines).startswith('1 AED = 0.27229')
+    assert next(lines) == '1 USD = 3.67246 AED\n'
+    assert next(lines).startswith('1 ALL = 0.0069189')
+    assert next(lines) == '1 USD = 144.529793 ALL\n'
+    assert next(lines).startswith('1 ANG = 0.55865')
+    assert next(lines) == '1 USD = 1.79 ANG\n'
+
+def test_one_rate(historical1_responder, output):
+    config = build_config(historical1_responder, from_currency='ANG')
+    lines = lines_from_run(config, output)
+    assert next(lines).startswith('1 ANG = 0.55865')
+    assert next(lines) == '1 USD = 1.79 ANG\n'
+    assert next(lines, None) is None
+
+def test_conversion(historical1_responder, output):
+    config = build_config(historical1_responder, amount=10, from_currency='AED')
+    lines = lines_from_run(config, output)
+    # FIXME: Assertion probably changes after we deal with precision right.
+    assert next(lines).startswith('10 AED = 2.72297')
+    assert next(lines, None) is None
+
+def test_back_conversion(historical1_responder, output):
+    config = build_config(historical1_responder,
+                          amount=2, from_currency='USD', to_currency='ALL')
+    lines = lines_from_run(config, output)
+    # FIXME: Assertion probably changes after we deal with precision right.
+    assert next(lines) == '2 USD = 289.059586 ALL\n'
+    assert next(lines, None) is None