Gigasecond template (#2135)

* Add gigasecond test template and generate tests.

* Add datetime import.

* gigasecond: add test template

Adds the gigasecond test template. Addresses most of the concerns on the
defunct #2066 submitted by @simonbcodes, however the `strptime` fix
suggested by @cmccandless was brittle, as some of the incoming data had
time data.

We'd _maybe_ want to add a `dateutil` dependency if the canonical data
strays in any way from bog standard ISO 8601 dates, but hopefully if
that happens the `datetime.fromisoformat` calls here will blow up and
let us know.

Closes #1950

* gigasecond: generate with dateutil parse

Adds a dependency to the generator, but shifts the work off the student.
As an added benefit should parse a lot more than fromisoformat would.

Must be merged _after_ #2134.

* Update requirements-generator.txt

Woops!

Co-Authored-By: Corey McCandless <[email protected]>

Author: yawpitch

bin/generate_tests.py

@@ -37,6 +37,7 @@
 from textwrap import wrap
 
 from jinja2 import Environment, FileSystemLoader, TemplateNotFound, UndefinedError
+from dateutil.parser import parse
 
 VERSION = "0.2.1"
 
@@ -81,6 +82,26 @@ def wrap_overlong(string, width=70):
     return ["{0!r} \\".format(w) for w in wrap(string, width)]
 
 
+def parse_datetime(string, strip_module=False):
+    """
+    Parse a (hopefully ISO 8601) datestamp to a datetime object and
+    return its repr for use in a jinja2 template.
+
+    If used the template will need to import the datetime module.
+
+        import datetime
+
+    However if strip_module is True then the template will need to 
+    import the datetime _class_ instead.
+
+        from datetime import datetime
+    """
+    result = repr(parse(string))
+    if strip_module:
+        return result.replace("datetime.", "", 1)
+    return result
+
+
 def get_tested_properties(spec):
     """
     Get set of tested properties from spec. Include nested cases.
@@ -258,6 +279,7 @@ def generate(
     env.filters["camel_case"] = camel_case
     env.filters["wrap_overlong"] = wrap_overlong
     env.filters["regex_replace"] = regex_replace
+    env.filters["parse_datetime"] = parse_datetime
     env.tests["error_case"] = error_case
     result = True
     for exercise in sorted(glob(os.path.join("exercises", exercise_glob))):

exercises/gigasecond/.meta/template.j2

@@ -0,0 +1,15 @@
+{%- import "generator_macros.j2" as macros with context -%}
+from datetime import datetime
+{{ macros.header() }}
+
+class {{ exercise | camel_case }}Test(unittest.TestCase):
+    {% for supercase in cases -%}
+    {% for case in supercase["cases"] -%}
+    {% set input = case["input"]["moment"] | parse_datetime(strip_module=true) -%}
+    {% set expected = case["expected"] | parse_datetime(strip_module=true) -%}
+    def test_{{ case["description"] | to_snake }}(self):
+        self.assertEqual({{ case["property"] }}({{ input }}), {{ expected }})
+    {% endfor %}
+    {% endfor %}
+
+{{ macros.footer() }}

exercises/gigasecond/gigasecond_test.py

@@ -1,44 +1,37 @@
-import unittest
 from datetime import datetime
+import unittest
 
 from gigasecond import add
 
-
 # Tests adapted from `problem-specifications//canonical-data.json` @ v2.0.0
 
+
 class GigasecondTest(unittest.TestCase):
     def test_date_only_specification_of_time(self):
         self.assertEqual(
-            add(datetime(2011, 4, 25)),
-            datetime(2043, 1, 1, 1, 46, 40))
+            add(datetime(2011, 4, 25, 0, 0)), datetime(2043, 1, 1, 1, 46, 40)
+        )
 
-    def test_another_date_only_specification_of_time(self):
+    def test_second_test_for_date_only_specification_of_time(self):
         self.assertEqual(
-            add(datetime(1977, 6, 13)),
-            datetime(2009, 2, 19, 1, 46, 40))
+            add(datetime(1977, 6, 13, 0, 0)), datetime(2009, 2, 19, 1, 46, 40)
+        )
 
-    def test_one_more_date_only_specification_of_time(self):
+    def test_third_test_for_date_only_specification_of_time(self):
         self.assertEqual(
-            add(datetime(1959, 7, 19)),
-            datetime(1991, 3, 27, 1, 46, 40))
+            add(datetime(1959, 7, 19, 0, 0)), datetime(1991, 3, 27, 1, 46, 40)
+        )
 
     def test_full_time_specified(self):
         self.assertEqual(
-            add(datetime(2015, 1, 24, 22, 0, 0)),
-            datetime(2046, 10, 2, 23, 46, 40))
+            add(datetime(2015, 1, 24, 22, 0)), datetime(2046, 10, 2, 23, 46, 40)
+        )
 
     def test_full_time_with_day_roll_over(self):
         self.assertEqual(
-            add(datetime(2015, 1, 24, 23, 59, 59)),
-            datetime(2046, 10, 3, 1, 46, 39))
-
-    def test_yourself(self):
-        # customize this to test your birthday and find your gigasecond date:
-        your_birthday = datetime(1970, 1, 1)
-        your_gigasecond = datetime(2001, 9, 9, 1, 46, 40)
-
-        self.assertEqual(add(your_birthday), your_gigasecond)
+            add(datetime(2015, 1, 24, 23, 59, 59)), datetime(2046, 10, 3, 1, 46, 39)
+        )
 
 
-if __name__ == '__main__':
+if __name__ == "__main__":
     unittest.main()

requirements-generator.txt

@@ -1,3 +1,4 @@
 black==19.3b0
 flake8==3.7.8
 Jinja2==2.10.1
+python-dateutil==2.8.1