> ## Please edit the corresponding file in [/packages/mermaid/src/docs/community/development.md](../../packages/mermaid/src/docs/community/development.md).
# Contributing to Mermaid
## Contents
- [Technical Requirements and Setup](#technical-requirements-and-setup)
- [npx](https://docs.npmjs.com/cli/v8/commands/npx) the packaged executor in npm. This is needed [to install pnpm.](#2-install-pnpm)
Follow [the setup steps below](#setup) to install them and verify they are working
### Setup
Follow these steps to set up the environment you need to work on code and/or documentation.
#### 1. Fork and clone the repository
In GitHub, you first _fork_ a repository when you are going to make changes and submit pull requests.
Then you _clone_ a copy to your local development machine (e.g. where you code) to make a copy with all the files to work with.
[Here is a GitHub document that gives an overview of the process.](https://docs.github.com/en/get-started/quickstart/fork-a-repo)
#### 2. Install pnpm
Once you have cloned the repository onto your development machine, change into the `mermaid` project folder so that you can install `pnpm`. You will need `npx` to install pnpm because volta doesn't support it yet.
Ex:
```bash
# Change into the mermaid directory (the top level director of the mermaid project repository)
cd mermaid
# npx is required for first install because volta does not support pnpm yet
npx pnpm install
```
#### 3. Verify Everything Is Working
Once you have installed pnpm, you can run the `test` script to verify that pnpm is working _and_ that the repository has been cloned correctly:
```bash
pnpm test
```
The `test` script and others are in the top-level `package.json` file.
Once the release happens we add a tag to the `release` branch and merge it with `master`. The live product and on-line documentation are what is in the `master` branch.
If your work is specific to a single diagram type, it is a good idea to put the diagram type at the start of the description. This will help us keep release notes organized: it will help us keep changes for a diagram type together.
**Ex: A new feature described in issue 2945 that adds a new arrow type called 'florbs' to state diagrams**
`feature/2945_state-diagram-new-arrow-florbs`
**Ex: A bug described in issue 1123 that causes random ugly red text in multiple diagram types**
`bug/1123_fix_random_ugly_red_text`
### 2. Write Tests
Tests ensure that each function, module, or part of code does what it says it will do. This is critically
important when other changes are made to ensure that existing code is not broken (no regression).
Just as important, the tests act as _specifications:_ they specify what the code does (or should do).
Whenever someone is new to a section of code, they should be able to read the tests to get a thorough understanding of what it does and why.
If you are fixing a bug, you should add tests to ensure that your code has actually fixed the bug, to specify/describe what the code is doing, and to ensure the bug doesn't happen again.
(If there had been a test for the situation, the bug never would have happened in the first place.)
You may need to change existing tests if they were inaccurate.
If you are adding a feature, you will definitely need to add tests. Depending on the size of your feature, you may need to add integration tests.
#### Unit Tests for Parsing
If you are adding or changing the text that describes a diagram (the _grammar_), you will need to add (or change) tests for the _parser._
#### Integration/End-to-End (e2e) tests
These test the rendering and visual appearance of the diagrams.
This ensures that the rendering of that feature in the e2e will be reviewed in the release process going forward. Less chance that it breaks!
To start working with the e2e tests:
1. Run `pnpm run dev` to start the dev server (or use the `pnpm dev` script)
2. Start **Cypress** by running `pnpm exec cypress open` in the **mermaid** folder (or use the `pnpm cypress:open` script).
The rendering tests are very straightforward to create. There is a function `imgSnapshotTest`, which takes a diagram in text form and the mermaid options, and it renders that diagram in Cypress.
When running in CI it will take a snapshot of the rendered diagram and compare it with the snapshot from last build and flag it for review if it differs.
This is what a rendering test looks like:
```js
it('should render forks and joins', () => {
imgSnapshotTest(
`
stateDiagram
state fork_state <<fork>>
[*] --> fork_state
fork_state --> State2
fork_state --> State3
state join_state <<join>>
State2 --> join_state
State3 --> join_state
join_state --> State4
State4 --> [*]
`,
{ logLevel: 0 }
);
cy.get('svg');
});
```
**_\[TODO - running the tests against what is expected in development. ]_**
**_\[TODO - how to generate new screenshots]_**
....
### 3. Update Documentation
If the users have no way to know that things have changed, then you haven't really _fixed_ anything for the users; you've just added to making Mermaid feel broken.
Likewise, if users don't know that there is a new feature that you've implemented, it will forever remain unknown and unused.
The documentation has to be updated to users know that things have changed and added!
We know it can sometimes be hard to code _and_ write user documentation.
Create another issue specifically for the documentation.\
You will need to help with the PR, but definitely ask for help if you feel stuck.
When it feels hard to write stuff out, explaining it to someone and having that person ask you clarifying questions can often be 80% of the work!]
When in doubt, write up and submit what you can. It can be clarified and refined later. (With documentation, something is better than nothing!)
### 4. Submit your pull request
**\[TODO - PR titles should start with (fix | feat | ....)]**
We make all changes via Pull Requests (PRs). As we have many Pull Requests from developers new to Mermaid, \
we have put in place a process wherein _knsv, Knut Sveidqvist_ is the primary reviewer of changes and merging pull requests. The process is as follows:
- Large changes are reviewed by knsv or other developer asked to review by knsv
- Smaller, low-risk changes like dependencies, documentation, etc. can be reviewed and merged by active collaborators
**Reminder: Pull Requests should be submitted to the develop branch.**
If you want to propose changes to how the documentation is _organized_, such as adding a new section or re-arranging or renaming a section, you must update the **sidebar navigation.**
The sidebar navigation is defined in [the vitepress configuration file config.ts](../.vitepress/config.ts).
The contents of <https://mermaid-js.github.io/mermaid/> are based on the docs from the `master` branch. Updates committed to the `master` branch are reflected in the [Mermaid Docs](https://mermaid-js.github.io/mermaid/) once released.
We encourage contributions to the documentation at [packages/mermaid/src/docs in the _develop_ branch](https://github.com/mermaid-js/mermaid/tree/develop/packages/mermaid/src/docs). We publish documentation to GitHub Pages with [Docsify](https://www.youtube.com/watch?v=TV88lp7egMw&t=3s)
**_\[TODO - how to preview the documents on a local machine? how to run VitePress?]_**
If you want to preview the whole documentation site on your machine, you need to install `docsify-cli`:
Markdown is used to format the text, for more information about Markdown [see the GitHub Markdown help page](https://help.github.com/en/github/writing-on-github/basic-writing-and-formatting-syntax).
If you find an open issue or discussion thread that is similar to your question but isn't answered,
you can let us know that you are also interested in it. **_\[TODO: describe upvoting]_**
This helps the team know the relative interest in something and helps them set priorities and assignments.
Feel free to add to the discussion on the issue or topic.
If you can't find anything that already addresses your question or suggestion, _open a new issue:_
Log in to [GitHub.com](https://www.github.com), open or append to an issue [using the GitHub issue tracker of the mermaid-js repository](https://github.com/mermaid-js/mermaid/issues?q=is%3Aissue+is%3Aopen+label%3A%22Area%3A+Documentation%22).
### How to Contribute a Suggestion
## Last Words
Don't get daunted if it is hard in the beginning. We have a great community with only encouraging words. So, if you get stuck, ask for help and hints in the Slack forum. If you want to show off something good, show it off there.
[Join our Slack community if you want closer contact!](https://join.slack.com/t/mermaid-talk/shared_invite/enQtNzc4NDIyNzk4OTAyLWVhYjQxOTI2OTg4YmE1ZmJkY2Y4MTU3ODliYmIwOTY3NDJlYjA0YjIyZTdkMDMyZTUwOGI0NjEzYmEwODcwOTE)
