3. Development

This section only needs to be read by developers of the nocaselist project, including people who want to make a fix or want to test the project.

3.1. Repository

The repository for the nocaselist project is on GitHub:

https://github.com/pywbem/nocaselist

3.2. Setting up the development environment

If you have write access to the Git repo of this project, clone it using its SSH link, and switch to its working directory:
```
$ git clone git@github.com:pywbem/nocaselist.git
$ cd nocaselist
```
If you do not have write access, create a fork on GitHub and clone the fork in the way shown above.
It is recommended that you set up a virtual Python environment. Have the virtual Python environment active for all remaining steps.
Install the project for development. This will install Python packages into the active Python environment, and OS-level packages:
```
$ make develop
```
This project uses Make to do things in the currently active Python environment. The command:
```
$ make
```
displays a list of valid Make targets and a short description of what each target does.

3.3. Building the documentation

The ReadTheDocs (RTD) site is used to publish the documentation for the project package at https://nocaselist.readthedocs.io/

This page is automatically updated whenever the Git repo for this package changes the branch from which this documentation is built.

In order to build the documentation locally from the Git work directory, execute:

$ make builddoc

The top-level document to open with a web browser will be build_doc/html/docs/index.html.

3.4. Testing

All of the following make commands run the tests in the currently active Python environment.

The package files that are tested are those in the nocaselist directory in the main repository directory.

The test case files and any utility functions they use are always used from the tests directory in the main repository directory.

The tests directory has the following subdirectory structure:

tests
 +-- unittest            Unit tests
 +-- installtest         Installation tests

There are the following types of tests:

Unit tests

These tests can be run standalone, and the tests validate their results automatically.

They are run by executing:
```
$ make test
```
Test execution can be modified by a number of environment variables, as documented in the make help (execute make help).
Installation tests

These tests can be run standalone, and the tests validate their results automatically.

They are run by executing:
```
$ make installtest
```

To run the unit tests in all supported Python environments, the Tox tool can be used. It creates the necessary virtual Python environments and executes make test (i.e. the unit tests) in each of them.

For running Tox, it does not matter which Python environment is currently active, as long as the Python tox package is installed in it:

$ tox                              # Run tests on all supported Python versions
$ tox -e py38                      # Run tests on Python 3.8

3.5. Contributing

Third party contributions to this project are welcome!

In order to contribute, create a Git pull request, considering this:

Test is required.
Each commit should only contain one “logical” change.
A “logical” change should be put into one commit, and not split over multiple commits.
Large new features should be split into stages.
The commit message should not only summarize what you have done, but explain why the change is useful.

What comprises a “logical” change is subject to sound judgement. Sometimes, it makes sense to produce a set of commits for a feature (even if not large). For example, a first commit may introduce a (presumably) compatible API change without exploitation of that feature. With only this commit applied, it should be demonstrable that everything is still working as before. The next commit may be the exploitation of the feature in other components.

For further discussion of good and bad practices regarding commits, see:

Further rules:

The following long-lived branches exist and should be used as targets for pull requests:
- master - for everything (fixes, new functions)
We use topic branches for everything!
- Based upon the intended long-lived branch, if no dependencies
- Based upon an earlier topic branch, in case of dependencies
- It is valid to rebase topic branches and force-push them.
We use pull requests to review the branches.
- Use the long-lived branch master as a merge target.
- Review happens as comments on the pull requests.
- At least one approval is required for merging.
GitHub meanwhile offers different ways to merge pull requests. We merge pull requests by rebasing the commit from the pull request.

3.6. Releasing a version to PyPI

This section describes how to release a version of nocaselist to PyPI.

It covers all variants of versions that can be released:

Releasing a new major version (Mnew.0.0) based on the master branch
Releasing a new minor version (M.Nnew.0) based on the master branch
Releasing a new update version (M.N.Unew) based on the master branch

The description assumes that the pywbem/nocaselist Github repo is cloned locally and its upstream repo is assumed to have the Git remote name origin.

Any commands in the following steps are executed in the main directory of your local clone of the pywbem/nocaselist Git repo.

Set shell variables for the version that is being released and the branch it is based on:
- MNU - Full version M.N.U that is being released
- MN - Major and minor version M.N of that full version
- BRANCH - Name of the branch the version that is being released is based on
When releasing a new major version (e.g. 1.0.0) based on the master branch:
```
MNU=1.0.0
MN=1.0
BRANCH=master
```
When releasing a new minor version (e.g. 0.9.0) based on the master branch:
```
MNU=0.9.0
MN=0.9
BRANCH=master
```
When releasing a new update version (e.g. 0.8.1) based on the master branch:
```
MNU=0.8.1
MN=0.8
BRANCH=master
```

Create a topic branch for the version that is being released:

git checkout ${BRANCH}
git pull
git checkout -b release_${MNU}

Edit the change log:
```
vi docs/changes.rst
```
and make the following changes in the section of the version that is being released:
- Finalize the version.
- Change the release date to today’s date.
- Make sure that all changes are described.
- Make sure the items shown in the change log are relevant for and understandable by users.
- In the “Known issues” list item, remove the link to the issue tracker and add text for any known issues you want users to know about.
- Remove all empty list items.
Update the authors:
```
make authors
```

Commit your changes and push the topic branch to the remote repo:

git commit -asm "Release ${MNU}"
git push --set-upstream origin release_${MNU}

On GitHub, create a Pull Request for branch release_M.N.U. This will trigger the CI runs.

When creating Pull Requests, GitHub by default targets the master branch.
On GitHub, close milestone M.N.U.
On GitHub, once the checks for the Pull Request for branch start_M.N.U have succeeded, merge the Pull Request (no review is needed). This automatically deletes the branch on GitHub.

Add a new tag for the version that is being released and push it to the remote repo. Clean up the local repo:

git checkout ${BRANCH}
git pull
git branch -D release_${MNU}
git branch -D -r origin/release_${MNU}
git tag -f ${MNU}
git push -f --tags

On GitHub, edit the new tag M.N.U, and create a release description on it. This will cause it to appear in the Release tab.

You can see the tags in GitHub via Code -> Releases -> Tags.
Upload the package to PyPI:
```
make upload
```
This will show the package version and will ask for confirmation.

Attention! This only works once for each version. You cannot release the same version twice to PyPI.

Verify that the released version arrived on PyPI at https://pypi.python.org/pypi/nocaselist/

3.7. Starting a new version

This section shows the steps for starting development of a new version of the nocaselist project in its Git repo.

This section covers all variants of new versions:

Starting a new major version (Mnew.0.0) based on the master branch
Starting a new minor version (M.Nnew.0) based on the master branch
Starting a new update version (M.N.Unew) based on the master branch

The description assumes that the pywbem/nocaselist Github repo is cloned locally and its upstream repo is assumed to have the Git remote name origin.

Any commands in the following steps are executed in the main directory of your local clone of the pywbem/nocaselist Git repo.

Set shell variables for the version that is being started and the branch it is based on:
- MNU - Full version M.N.U that is being started
- MN - Major and minor version M.N of that full version
- BRANCH - Name of the branch the version that is being started is based on
When starting a new major version (e.g. 1.0.0) based on the master branch:
```
MNU=1.0.0
MN=1.0
BRANCH=master
```
When starting a new minor version (e.g. 0.9.0) based on the master branch:
```
MNU=0.9.0
MN=0.9
BRANCH=master
```
When starting a new minor version (e.g. 0.8.1) based on the master branch:
```
MNU=0.8.1
MN=0.8
BRANCH=master
```

Create a topic branch for the version that is being started:

git checkout ${BRANCH}
git pull
git checkout -b start_${MNU}

Edit the change log:

vi docs/changes.rst

and insert the following section before the top-most section:

nocaselist M.N.U.dev1
---------------------

Released: not yet

**Incompatible changes:**

**Deprecations:**

**Bug fixes:**

**Enhancements:**

**Cleanup:**

**Known issues:**

* See `list of open issues`_.

.. _`list of open issues`: https://github.com/pywbem/nocaselist/issues

Commit your changes and push them to the remote repo:

git commit -asm "Start ${MNU}"
git push --set-upstream origin start_${MNU}

On GitHub, create a Pull Request for branch start_M.N.U.

When creating Pull Requests, GitHub by default targets the master branch.
On GitHub, create a milestone for the new version M.N.U.

You can create a milestone in GitHub via Issues -> Milestones -> New Milestone.
On GitHub, go through all open issues and pull requests that still have milestones for previous releases set, and either set them to the new milestone, or to have no milestone.
On GitHub, once the checks for the Pull Request for branch start_M.N.U have succeeded, merge the Pull Request (no review is needed). This automatically deletes the branch on GitHub.
Add release start tag and clean up the local repo:

Note: An initial tag is necessary because the automatic version calculation done by setuptools-scm uses the most recent tag in the commit history and increases the least significant part of the version by one, without providing any controls to change that behavior.
```
git checkout ${BRANCH}
git pull
git branch -D start_${MNU}
git branch -D -r origin/start_${MNU}
git tag -f ${MNU}a0
git push -f --tags
```