[Sugar-devel] Unit testing in sugar platform: using python mock

[Daniel Narvaez]

Hey Manuel!

Your example looks pretty cool and I think the fact that it's in python3
makes it a no brainer. I think we can just add a dep in sugar-build, no
need to build it.

This is what it's going to look like on the chroot branch.

diff --git a/build/root.json b/build/root.json
index 45967f6..e5d0fd5 100644
--- a/build/root.json
+++ b/build/root.json
@@ -71,7 +71,8 @@
             "telepathy-mission-control",
             "zip",
             "unzip",
-            "libwebkit2gtk"
+            "libwebkit2gtk",
+            "python-mock"
         ],
         "sugar-artwork": [
             "gnome-common",

We should probably wait to get the first patch using it before landing this.


On 10 July 2013 16:15, Miguel González <migonzalvar at activitycentral.com>wrote:

> TL;DR: Python mock library is very useful. I share with you an example.
> Could it be added on sugar-build?
>
>
> While I was working on bringing 3G database support to sugar platform, I
> needed to test persistent storage on GConf and locale environment variables.
>
> At the end I didn't include the test for this functionality in the pull
> request [1] but I would like to share with the list my approach.
>
> Sorry because it is a long message. I will appreciate to get some feedback
> about including mock library to sugar testing.
>
>
> - First of all, I had to install mock [2]. I don't know how to do it
> properly using osbuild. I do think it would be very useful for testing.
> BTW, this library is on Python 3.3 standard library as unittest.mock.
>
>
> - Then I imported patch function:
>
> ```
> from mock import patch
> ```
>
>
> - Next, I imported GConf keys an create a fake GConf client. It just a key
> data store with initializable values:
>
> ```
> from cpsection.modemconfiguration.model import (
>     GCONF_SP_COUNTRY, GCONF_SP_PROVIDER, GCONF_SP_PLAN
> )
>
> class FakeGConfClient(object):
>     store = {
>         GCONF_SP_COUNTRY: '',
>         GCONF_SP_PROVIDER: '',
>         GCONF_SP_PLAN: '',
>     }
>
>     def __init__(self, **kwargs):
>         self.store.update(kwargs)
>
>     def get_string(self, key):
>         return self.store[key]
>
>     def set_string(self, key, value):
>         self.store[key] = value
>         return
>
>     def get_int(self, key):
>         return self.store[key]
>
>     def set_int(self, key, value):
>         self.store[key] = value
>         return
> ```
>
> - The test suite has 3 parts.
>
> 1. On setUp() I patch GConf.Client.get_default to use my false client:
> 2. On test_guess_country() I patch locale.getdefaultlocale() to return an
> arbitrary value.
> 3. Finally I instantiate the main class and assert default country is the
> expected one
>
> ```
> class ServiceProvidersGuessCountry(unittest.TestCase):
>     def setUp(self):  # (1)
>         gconf_patcher = patch('gi.repository.GConf.Client.get_default')
>         gconf_mock = gconf_patcher.start()
>         gconf_mock.return_value = FakeGConfClient(GCONF_SP_COUNTRY=None)
>         self.addCleanup(gconf_patcher.stop)
>
>     def test_guess_country(self):
>         LOCALE = ('hi_IN', 'UTF-8')
>         default_country_code = LOCALE[0][3:5].lower()
>
>         with patch('locale.getdefaultlocale') as locale_mock:  # (2)
>             locale_mock.return_value = LOCALE
>
>             db = ServiceProvidersDatabase()
>             country = db.get_country()
>             self.assertEqual(country.code, default_country_code)  # (3)
> ```
>
> What do you think?
>
>
> [1] https://github.com/sugarlabs/sugar/pull/58
>
> [2] http://www.voidspace.org.uk/python/mock/
> --
> Miguel González
> Activity Central: http://www.activitycentral.com
>
> _______________________________________________
> Sugar-devel mailing list
> Sugar-devel at lists.sugarlabs.org
> http://lists.sugarlabs.org/listinfo/sugar-devel
>
>


-- 
Daniel Narvaez
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