# Development Guide

This is a guide for developers who would like to contribute to this project.

If you're interested in contributing to mycli, thank you. We'd love your help!
You'll always get credit for your work.

## GitHub Workflow

1. [Fork the repository](https://github.com/dbcli/mycli) on GitHub.

2. Clone your fork locally:
    ```bash
    $ git clone <url-for-your-fork>
    ```

3. Add the official repository (`upstream`) as a remote repository:
    ```bash
    $ git remote add upstream git@github.com:dbcli/mycli.git
    ```

4. Set up a [virtual environment](http://docs.python-guide.org/en/latest/dev/virtualenvs)
   for development:

    ```bash
    $ cd mycli
    $ pip install virtualenv
    $ virtualenv mycli_dev
    ```

    We've just created a virtual environment that we'll use to install all the dependencies
    and tools we need to work on mycli. Whenever you want to work on mycli, you
    need to activate the virtual environment:

    ```bash
    $ source mycli_dev/bin/activate
    ```

    When you're done working, you can deactivate the virtual environment:

    ```bash
    $ deactivate
    ```

5. Install the dependencies and development tools:

    ```bash
    $ pip install -r requirements-dev.txt
    $ pip install --editable .
    ```

6. Create a branch for your bugfix or feature based off the `main` branch:

    ```bash
    $ git checkout -b <name-of-bugfix-or-feature> main
    ```

7. While you work on your bugfix or feature, be sure to pull the latest changes from `upstream`. This ensures that your local codebase is up-to-date:

    ```bash
    $ git pull upstream main
    ```

8. When your work is ready for the mycli team to review it, push your branch to your fork:

    ```bash
    $ git push origin <name-of-bugfix-or-feature>
    ```

9. [Create a pull request](https://help.github.com/articles/creating-a-pull-request-from-a-fork/)
   on GitHub.


## Running the Tests

While you work on mycli, it's important to run the tests to make sure your code
hasn't broken any existing functionality. To run the tests, just type in:

```bash
$ ./setup.py test
```

Mycli supports Python 2.7 and 3.4+. You can test against multiple versions of
Python by running tox:

```bash
$ tox
```


### Test Database Credentials

The tests require a database connection to work. You can tell the tests which
credentials to use by setting the applicable environment variables:

```bash
$ export PYTEST_HOST=localhost
$ export PYTEST_USER=mycli
$ export PYTEST_PASSWORD=myclirocks
$ export PYTEST_PORT=3306
$ export PYTEST_CHARSET=utf8
```

The default values are `localhost`, `root`, no password, `3306`, and `utf8`.
You only need to set the values that differ from the defaults.

If you would like to run the tests as a user with only the necessary privileges,
create a `mycli` user and run the following grant statements.

```sql
GRANT ALL PRIVILEGES ON `mycli_%`.* TO 'mycli'@'localhost';
GRANT SELECT ON mysql.* TO 'mycli'@'localhost';
GRANT SELECT ON performance_schema.* TO 'mycli'@'localhost';
```

### CLI Tests

Some CLI tests expect the program `ex` to be a symbolic link to `vim`.

In some systems (e.g. Arch Linux) `ex` is a symbolic link to `vi`, which will
change the output and therefore make some tests fail.

You can check this by running:
```bash
$ readlink -f $(which ex)
```


## Coding Style

Mycli requires code submissions to adhere to
[PEP 8](https://www.python.org/dev/peps/pep-0008/).
It's easy to check the style of your code, just run:

```bash
$ ./setup.py lint
```

If you see any PEP 8 style issues, you can automatically fix them by running:

```bash
$ ./setup.py lint --fix
```

Be sure to commit and push any PEP 8 fixes.

## Releasing a new version of mycli

You have been made the maintainer of `mycli`? Congratulations! We have a release script to help you:

```sh
> python release.py --help
Usage: release.py [options]

Options:
  -h, --help           show this help message and exit
  -c, --confirm-steps  Confirm every step. If the step is not confirmed, it
                       will be skipped.
  -d, --dry-run        Print out, but not actually run any steps.
```

To release a new version of the package:

* Create and merge a PR to bump the version in the changelog ([example PR](https://github.com/dbcli/mycli/pull/1043)).
* Pull `main` and bump the version number inside `mycli/__init__.py`. Do not check in - the release script will do that.
* Make sure you have the dev requirements installed: `pip install -r requirements-dev.txt -U --upgrade-strategy only-if-needed`.
* Finally, run the release script: `python release.py`.