# Contributing to BOM Library

As a contributor, here are the guidelines we would like you to follow:

 - [Submission Guidelines](#submission-guidelines)
 - [Coding Rules](#coding-rules)
 - [Commit Message Guidelines](#commit-message-guidelines)

* For a **Major Feature**, first write a user story and outline your proposal so that it can be
discussed and prioritied by the product owner. This will also allow us to better coordinate our efforts, assess value for the business, prevent duplication of work,
and help you to craft the change so that it is successfully accepted into the project.
* **Small Features** can be crafted and directly [submitted as a Pull Request](#submitting-a-pull-request).

## Submission Guidelines

### Submitting an Issue

Before you submit an issue, please search the backlog and ask QA, maybe an issue for your problem already exists and the discussion might inform you of workarounds readily available.

We want to fix all the issues as soon as possible, but before fixing a bug we need to reproduce and confirm it. In order to reproduce bugs, we will systematically ask you to provide a minimal reproduction. Having a minimal reproducible scenario gives us a wealth of important information without going back & forth to you with additional questions.

A minimal reproduction allows us to quickly confirm a bug (or point out a coding problem) as well as confirm that we are fixing the right problem.

You can file new issues by reporting them to a QA person in the Ultima-Thule team.


### Submitting a Pull Request
Before you submit your Pull Request (PR) consider the following guidelines:

1. Be sure that there is a story ticket in jira describing the problem you're fixing, or documents the design for the feature you'd like to add.
  Discussing the design up front helps to ensure that we're ready to accept your work.
1. Clone the bom-tool repo.
1. Make your changes in a new git branch:

     ```shell
     git checkout -b fix/[TICKET NUMBER]_[DESCRIPTION] master
     ```

1. Create your patch, **including appropriate test cases**.
1. Follow our [Coding Rules](#coding-rules).
1. Run the full BOM Library test suite, as described in the [developer documentation][dev-doc],
  and ensure that all tests pass.
1. Rebase master and squash your commits:
    1. Make sure your local master branch is up to date.
    ```shell
    git checkout master && git pull && git checkout my-branch-name
    ```
    2. Rebase and squash
    ```shell
    git rebase master -i
    ```
1. Commit your changes using a descriptive commit message that follows our
  [commit message conventions](#commit-message-format).

     ```shell
     git commit -a
     ```
    Note: the optional commit `-a` command line option will automatically "add" and "rm" edited files.

1. Push your branch to BitBucket:

    ```shell
    git push origin my-fix-branch
    ```

1. In BitBucket, send a pull request to `bom-tool:master`.
* If we suggest changes then:
  * Make the required updates.
  * Re-run the BOM Library test suites to ensure tests are still passing.
  * Rebase your branch and force push to your BitBucket repository (this will update your Pull Request):

    ```shell
    git rebase master -i
    git push -f
    ```

That's it! Thank you for your contribution!

#### After your pull request is merged

After your pull request is merged, you can safely delete your branch and pull the changes
from the main (upstream) repository:

* Delete the remote branch on BitBucket either through the BitBucket web UI or your local shell as follows:

    ```shell
    git push origin --delete my-fix-branch
    ```

* Check out the master branch:

    ```shell
    git checkout master -f
    ```

* Delete the local branch:

    ```shell
    git branch -D my-fix-branch
    ```

* Update your master with the latest upstream version:

    ```shell
    git pull --ff upstream master
    ```

## Coding Rules
To ensure consistency throughout the source code, keep these rules in mind as you are working:

* All features or bug fixes **must be tested** by one or more specs (unit-tests).
* All public API methods **must be documented**. (Details TBC).
* We follow [Google's JavaScript Style Guide][js-style-guide], but wrap all code at
  **100 characters**. An automated formatter is available, see
  [DEVELOPER.md](docs/DEVELOPER.md#clang-format).

## Commit Message Guidelines

We have very precise rules over how our git commit messages can be formatted.  This leads to **more
readable messages** that are easy to follow when looking through the **project history**.  But also,
we use the git commit messages to **generate the BOM Library change log and versioning**.

### Commit Message Format
Each commit message consists of a **header**, a **body** and a **footer**.  The header has a special
format that includes a **type**, a **scope** and a **subject**:

```
<type>(<scope>): <subject>
<BLANK LINE>
<body>
<BLANK LINE>
<footer>
```

The **header** is mandatory and the **scope** of the header is optional.

Any line of the commit message cannot be longer 100 characters! This allows the message to be easier
to read on BitBucket as well as in various git tools.

The footer should contain a the ticket number if any.


```
docs(changelog): update changelog to beta.5
```
```
fix(release): need to depend on latest rxjs and zone.js

The version in our package.json gets copied to the one we publish, and users need the latest of these.
```

### Revert
If the commit reverts a previous commit, it should begin with `revert: `, followed by the header of the reverted commit. In the body it should say: `This reverts commit <hash>.`, where the hash is the SHA of the commit being reverted.

### Type
Must be one of the following:

* **build**: Changes that affect the build system or external dependencies (example scopes: scripts, cli, yarn)
* **ci**: Changes to our CI configuration files and scripts (example scopes: nginx, docker)
* **docs**: Documentation only changes
* **feat**: A new feature
* **fix**: A bug fix
* **perf**: A code change that improves performance
* **refactor**: A code change that neither fixes a bug nor adds a feature
* **style**: Changes that do not affect the meaning of the code (white-space, formatting, missing semi-colons, etc)
* **test**: Adding missing tests or correcting existing tests

### Scope
The scope should be the name of the npm package affected (as perceived by the person reading the changelog generated from commit messages.

The following is the list of supported scopes:

* **cart**
* **controls**
* **core**
* **feature-flag**
* **list**
* **logger**
* **maintenance**
* **management**
* **mapping**
* **shared**
* **view**
* **upgrade**

There are currently a few exceptions to the "use package name" rule:

* **packaging**: used for changes that change the npm package layout in all of our packages, e.g.
  public path changes, package.json changes done to all packages, d.ts file/format changes, changes
  to bundles, etc.
* **changelog**: used for updating the release notes in CHANGELOG.md
* none/empty string: useful for `style`, `test` and `refactor` changes that are done across all
  packages (e.g. `style: add missing semicolons`) and for docs changes that are not related to a
  specific package (e.g. `docs: fix typo in documentation`).

### Subject
The subject contains a succinct description of the change:

* use the imperative, present tense: "change" not "changed" nor "changes"
* don't capitalize the first letter
* no dot (.) at the end

### Body
Just as in the **subject**, use the imperative, present tense: "change" not "changed" nor "changes".
The body should include the motivation for the change and contrast this with previous behavior.

### Footer
The footer should contain any information about **Breaking Changes** and is also the place to
reference thw Jira ticket that this commit **Closes**.

**Breaking Changes** should start with the word `BREAKING CHANGE:` with a space or two newlines. The rest of the commit message is then used for this.