CONTRIBUTING.md

Contributing to Orca

Note that this section targets contributors. If you're interested in using Orca see the installation instructions.

Dev Installation

Prerequisites

• git
• Node.js. We recommend using Node.js v8.x, but all versions starting from v6 should work. Upgrading and managing node versions can be easily done using nvm or its Windows alternatives.
• npm v5.x and up (which ships by default with Node.js v8.x) to ensure that the package-lock.json file is used and updated correctly.

Clone the plotly.js repo

git clone https://github.com/plotly/orca.git
cd orca

Install Node.js dependencies

npm install

Install poppler

We haven't found a Node.js library that converts PDF files to EPS, so we use poppler. Orca also support EMF exports when inkscape is found in the environment. So to run the tests, you'll need to:

On Debian-flavored Linux:

apt-get poppler-utils inkscape

On OS X:

brew install poppler inkscape

On Windows:

Can anyone help us out?

Running tests

npm test

# or more granularly:

# just the standard linter
npm run test:lint

# just the unit tests (TAP tests using Node.js only)
npm run test:unit

# just the integration tests (using spectron)
npm run test:integration

To check test coverage:

npm run coverage

Packaging

We use electron-builder to pack up the orca executable. To do so locally, run:

npm run pack

the new executable will appear in the release/ directory.

Releases

At the moment, we manually upload the OS X, Windows, and Linux executables (built on Travis, AppVeyor and CircleCI respectively) on the Github release. It would be nice to automate this process somehow.

Checklist

• Make sure tests are passing off master on CircleCI
• Run git checkout master && git pull
• Update and commit the CHANGELOG.md according to the keepachangelog specs. Pro tip: use the GitHub compare URLs https://github.com/plotly/orca/compare/v<X.Y.Z>...master replacing <X.Y.Z> with the most recent orca version.
• Run npm version {patch | minor | major}, which automatically
  • bumps the version in the orca package.json
  • git commit, with message 'X.Y.Z'
  • git tag -a, adding a tag 'vX.Y.Z'
• Review version commit by e.g. git show HEAD
• Run git push && git push --tags
• Go to the release section and make a new release with title vX.Y.Z same as the git tag, then:
  • Copy the CHANGELOG items in the description field and add some extra info if you feel like it.
  • Grab the Linux build from CircleCI electron-pack-and-release job artifacts under the latest master build -> Artifacts -> release.zip
  • Grab the Windows build from AppVeyor under Latest Build -> Artifacts -> release.zip
  • Grab the Mac build automatically pushed to Amazon S3 from Travis. N.B. Select the latest build (largest number note: the folders are not necessarily sequential) -> release.zip
• Run npm publish
• Publish conda packages:
  • Download the following artifacts as above:
    • conda-linux-64.zip (CircleCI)
    • conda-win-64.zip (AppVeyor)
    • conda-osx-64.zip (Travis)
  • Unzip each artifact
    • conda-linux-64.zip becomes linux-64/plotly-orca-*.tar.bz2
    • conda-win-64.zip becomes win-64/plotly-orca-*.tar.bz2
    • conda-osx-64.zip becomes osx-64/plotly-orca-*.tar.bz2
  • From a conda environment with the anaconda-client package installed run anaconda login
  • Enter the credentials for the plotly anaconda channel
  • For each of the three plotly-orca-*.tar.bz2 files listed above, run anaconda upload /path/to/XX-64/plotly-orca-*.tar.bz2
  • Run anaconda logout
• 🍻

Overview

Writing testable code for Electron Apps

Electron creates an executable environment. That is, require('electron') does not do the same when executed as node index.js and electron index.js.

So, to write good unit tests, it becomes important to split logic that only runs in Electron from other things that can be run in Node.js. That's why in src/app/*, only the index.js files require Electron modules. The other modules are pure Node.js and are tested in test/unit/ using TAP. The Electron logic is itself tested using Spectron which is much slower and brittle.

Anatomy of an Orca component

Along with a name field, each component has a ping, an inject, a parse, a render and a convert method:

• ping (required, renderer process): method that send healthy signal from the renderer to main process
• inject (optional, main process): returns a string or an array of strings which is injected in the head of the app's HTML index file (e.g <script src="plotly.js"></script>)
• parse (required, main process): takes in a request body and coerces its options
• render (required, renderer process): takes options and returns image data
• convert (required, main process): converts image data to output head and body

Component modules are just plain objects, listing methods. Components aren't instantiated, their methods shouldn't depend on any this. We chose to not turn components into classes as this practice would be difficult to implement correctly in the main and renderer process at once.

Nomenclature for IPC callbacks

Orca is a heavy user of Electron's IPC (inter-process-communication) which in turn is callback heavy. To help us stay out of callback hell, we use the following terms to designates callbacks:

• At the end of the data-parse callback, we call the component module parse method as parse(body, componentOpts, sendToRenderer) where sendToRenderer is a callback.
• sendToRenderer transfers info from the main to the renderer process as sendToRenderer(errorCode, parseInfo).
• In the renderer process we then call the component module render method as render(info, componentOpts, sendToMain) where sendToMain is a callback.
• sendToMain transfers info from the renderer back to main process as sendToMain(errorCode, result)
• Back in the main process, the component module convert method is then called as convert(fullInfo, componentOpts, reply) when reply is (you guessed it) a callback.
• reply is then called as reply(errorCode, convertInfo).

What happened to nw.js?

Older Plotly devs might remember our old nw.js image server, but yeah Electron is way better than nw.js and a lot more people are using it. Using it for this project was a no-brainier.

Devs more experienced with nw.js should note: Electron apps juggle between a Node.js process (called the main process) and browser scripts (call the renderer process). Compared to nw.js, creating Electron apps requires a little more boiler plate, but Electron makes it much easier to know what globals you have available.

Code style