Add a mention of adding tests to CONTRIBUTING.md
@@ -83,7 +83,9 @@ Then you are good to go!
## Running tests
We have a lot of tests for various cases supported by repo2docker in the `tests/`
-subdirectory. These use [py.test](https://docs.pytest.org/).
+subdirectory. If you fix a bug or add new functionality consider adding a new
+test to prevent the bug from coming back. These use
+[py.test](https://docs.pytest.org/).
You can run all the tests with:
@@ -196,7 +198,8 @@ See the subsections below for more detailed instructions.
Once you've made the commit, please make a Pull Request to the `jupyter/repo2docker`
repository, with a description of what versions were bumped / what new packages were
-added and why.
+added and why. If you fix a bug or add new functionality consider adding a new
+test to prevent the bug from coming back/the feature breaking in the future.
## Creating a Release
