take advantage of click's type validation/coercion

(saves us having to write the stuff ourselves). Also adds a small
click plugin to do datetime parsing.

Sample output:

```
[leohemsted:~/dev/api]$ flask command create_provider_rates --help
Usage: flask command create_provider_rates [OPTIONS]

  Backfill rates for a given provider

Options:
  -p, --provider_name [mmg|firetext|ses]
                                  [required]
  -c, --cost FLOAT                Cost (pence) per message including decimals
                                  [required]
  -d, --valid_from DATE           [required]
  --help                          Show this message and exit.
[leohemsted:~/dev/api]$ flask command create_provider_rates -p ses -c 1.234 -d invalid
Usage: flask command create_provider_rates [OPTIONS]

Error: Invalid value for "-d" / "--valid_from": Could not parse datetime string "invalid" formatted as %Y-%m-%dT%H:%M:%S
```

app/commands.py

@@ -6,6 +6,7 @@ import functools
 import flask
 from flask import current_app
 import click
+from click_datetime import Datetime as click_dt
 
 from app import db
 from app.dao.monthly_billing_dao import (
@@ -49,17 +50,14 @@ class notify_command:
 
 
 @notify_command()
-@click.option('-p', '--provider_name', required=True, help='Provider name', type=click.Choice(PROVIDERS))
+@click.option('-p', '--provider_name', required=True, type=click.Choice(PROVIDERS))
 @click.option('-c', '--cost', required=True, help='Cost (pence) per message including decimals', type=float)
-@click.option('-d', '--valid_from', required=True, help="Date (%Y-%m-%dT%H:%M:%S) valid from")
+@click.option('-d', '--valid_from', required=True, type=click_dt(format='%Y-%m-%dT%H:%M:%S'))
 def create_provider_rates(provider_name, cost, valid_from):
     """
     Backfill rates for a given provider
     """
     cost = Decimal(cost)
-
-    valid_from = datetime.strptime('%Y-%m-%dT%H:%M:%S', valid_from)
-
     dao_create_provider_rates(provider_name, valid_from, cost)
 
 
@@ -194,7 +192,7 @@ def link_inbound_numbers_to_service():
 
 
 @notify_command()
-@click.option('-y', '--year', required=True, help="Use for integer value for year, e.g. 2017", type=int)
+@click.option('-y', '--year', required=True, help="e.g. 2017", type=int)
 def populate_monthly_billing(year):
     """
     Populate monthly billing table for all services for a given year.
@@ -228,14 +226,12 @@ def populate_monthly_billing(year):
 
 
 @notify_command()
-@click.option('-s', '--start_date', required=True, help="Date (%Y-%m-%d) start date inclusive")
+@click.option('-s', '--start_date', required=True, help="start date inclusive", type=click_dt(format='%Y-%m-%d'))
-@click.option('-e', '--end_date', required=True, help="Date (%Y-%m-%d) end date inclusive")
+@click.option('-e', '--end_date', required=True, help="end date inclusive", type=click_dt(format='%Y-%m-%d'))
 def backfill_processing_time(start_date, end_date):
     """
     Send historical performance platform stats.
     """
-    start_date = datetime.strptime(start_date, '%Y-%m-%d')
-    end_date = datetime.strptime(end_date, '%Y-%m-%d')
 
     delta = end_date - start_date
 

requirements.txt

@@ -7,6 +7,7 @@ Flask-Marshmallow==0.8.0
 Flask-Migrate==2.1.1
 Flask-SQLAlchemy==2.3.2
 Flask==0.12.2
+click-datetime==0.2
 gunicorn==19.7.1
 iso8601==0.1.12
 jsonschema==2.6.0

tests/app/test_commands.py

@@ -8,7 +8,7 @@ def test_backfill_processing_time_works_for_correct_dates(mocker, notify_api):
 
     # backfill_processing_time is a click.Command object - if you try invoking the callback on its own, it
     # throws a `RuntimeError: There is no active click context.` - so get at the original function using __wrapped__
-    backfill_processing_time.callback.__wrapped__('2017-08-01', '2017-08-03')
+    backfill_processing_time.callback.__wrapped__(datetime(2017, 8, 1), datetime(2017, 8, 3))
 
     assert send_mock.call_count == 3
     send_mock.assert_any_call(datetime(2017, 7, 31, 23, 0), datetime(2017, 8, 1, 23, 0))