From b14ae8cbb163f362300a6d05b51902fb2f629a80 Mon Sep 17 00:00:00 2001
From: Oliver Sanders <oliver.sanders@metoffice.gov.uk>
Date: Wed, 27 May 2020 12:37:18 +0100
Subject: [PATCH] tests: test option_parsers.Options

---
 cylc/flow/tests/option_parsers.py | 40 +++++++++++++++++++++++++++++++
 1 file changed, 40 insertions(+)
 create mode 100644 cylc/flow/tests/option_parsers.py

diff --git a/cylc/flow/tests/option_parsers.py b/cylc/flow/tests/option_parsers.py
new file mode 100644
index 00000000000..767a8cf739c
--- /dev/null
+++ b/cylc/flow/tests/option_parsers.py
@@ -0,0 +1,40 @@
+import optparse
+
+import pytest
+
+from cylc.flow.option_parsers import Options
+
+
+@pytest.fixture
+def simple_parser():
+    """Simple option parser."""
+    parser = optparse.OptionParser()
+    parser.add_option('-a', action='store')
+    parser.add_option('-b', action='store_true')
+    parser.add_option('-c', default='C')
+    return parser
+
+
+def test_options(simple_parser):
+    """It is a substitute for an optparse options object."""
+    options = Options(parser=simple_parser)
+    opts = options(a=1, b=True)
+
+    # we can access options as attributes
+    assert opts.a == 1
+    assert opts.b is True
+
+    # defaults are automatically substituted
+    assert opts.c == 'C'
+
+    # get-like syntax should work
+    assert opts.get('d', 42) == 42
+
+    # invalid keys result in KeyErrors
+    with pytest.raises(KeyError):
+        opts.d
+    with pytest.raises(KeyError):
+        opts(d=1)
+
+    # just for fun we can still use dict syntax
+    assert opts['a'] == 1