apps

The Apps Package

The Apps Package contains most of our client-side JavaScript, particularly the source code for the Blockly based 20 hour curriculum, Hour of Code, and our Droplet-based levels (including App Lab). Information about Blockly can be found in the wiki.

Blockly is a web-based, graphical programming editor. Users can drag blocks together to build an application. No typing required. Credit goes to these awesome developers and a small army of translators.

• Quick Start
• Contributing

Quick Start

Installing Apps

cd apps

# Machine setup (OSX with Homebrew)
brew install node
npm install -g grunt-cli yarn@1.22.5

# Perform first full build
yarn
npm run build

# automatically rebuild every time you make changes to source files
yarn start

Seeing your development version of Apps in Dashboard

1. To make your changes show up in dashboard, do the following after the first time you build apps:

• Set use_my_apps: true to your locals.yml config file.
• Run rake package:apps:symlink to pick up the configuration change.
• If you are currently running dashboard, stop and restart dashboard-server.

1. If you find your changes are not showing up within dashboard, you may have accidentally reverted your symlink to point to the pre-built version of apps (e.g. when switching branches or stashing changes). To check your symlink, run:

> ls -l dashboard/public/blockly

and look for something like:

lrwxr-xr-x  1 laurel  501  12 Apr 27 13:00 dashboard/public/blockly -> apps/build/package

If the symlink is in place, then as you rebuild apps, your results should show up in Dashboard. If not, run through step 1 again.

Building during development

Full build

To run a full development build (minus localization):

npm run build

• npm run build builds a 'debug' version with more readable javascript
• npm run build -- --app=maze builds a 'debug' version of only the maze app
• npm run build:dist builds a minified version suitable for production
• npm run clean will clean the build directory

See also: Full build with blockly changes

Running tests

npm test

• If you see an error like ReferenceError: Blockly is not defined or notes about missing npm packages, double check that you've run npm run build beforehand.
• Right now, the tests require a full/production build to pass. Failures like Cannot set property 'imageDimensions_' of undefined in setup steps may indicate that you are testing against a debug build.
• These tests will also be run via Circle CI when you create a pull request

To run an individual test, use the --entry option with npm run test:entry to target a file:

npm run test:entry -- --entry=./test/unit/gridUtilsTest.js

This option also works on directories, in which case all files within that directory and any subdirectories will be run:

npm run test:entry -- --entry=./test/unit/applab/

It's also possible to run an individual test or subset of tests with:

npm run test:unit -- --grep='TutorialExplorer'

To run integration tests for a certain level type:

LEVEL_TYPE=applab npm run test:integration

You can also use the --grep flag with integration tests:

LEVEL_TYPE=applab npm run test:integration --grep=ec_data_blocks

Rerun Tests Automatically

To rerun tests automatically on every file change, set the environment variable WATCH=1:

WATCH=1 npm run test:unit

This will work on any of the test commands.

Debugging Tests

To debug tests, your best bet is to run them in Chrome. Keep in mind that there can be subtle differences between Chrome and PhantomJS, so after fixing your test in Chrome, make sure it still works in PhantomJS. To run the tests in Chrome, use the BROWSER environment variable in conjunction with WATCH:

BROWSER=Chrome WATCH=1 npm run test:unit

A new chrome browser window will open where the tests will be running. You can click on the Debug button to open a new tab where you can then open the developer console to see everything that is happening. If you don't see the new chrome browser window, it may have opened behind your other windows.

Coverage Reports

Coverage reports can be generated for any collection of tests by specifying the COVERAGE=1 environment variable. Results will be placed in the coverage folder. For example, to see what code gets executed by unit tests, run:

COVERAGE=1 npm run test:unit

Then you can open up the html report with (note that the exact file path may be different):

open coverage/PhantomJS\ 2.1.1\ \(Mac\ OS\ X\ 0.0.0\)/index.html

Writing Tests

You can add new test files as /test/unit/*Tests.js; see /test/unit/feedbackTests.js as an example of adding a mock Blockly instance. Note that each test file in /test/unit/** should include tests for exactly one file in src/** and the test file should have the same file name as the file it tests (with Tests appended to it): i.e. don't create new unit test files that test lots and lots of different stuff.

In the event you need certain code to only be available when tests are running, you can use the IN_UNIT_TEST global, which will be set to true only when tests are running. For example:

if (IN_UNIT_TEST) {
  console.log("this log line will only show up when tests are run");
}

These if statements will be removed from production source files at build time.

The test runner starts a server which can serve files in the apps directory to your test code. Only allowlisted files and directories are available. See the config.karma.options.files array in Gruntfile.js for the allowlist. When fetching files served by the test runner, prefix the file path with /base/. For example, to load the test/audio/assets/win.mp3 file in an <audio> tag inside your test, you could write:

document.write('<audio src="/base/test/audio/assets/win.mp3"/>');

UI Component Style Guide & Tests

We use Storybook to generate a UI component style guide that you can use to discover what components are available to reuse as you build new features. See more in the apps/.storybook README.

Full build with blockly changes

1. Check out a local copy of blockly
2. Follow the directions in Building with apps

Analyzing bundle sizes

Bloated javascript bundles getting you down? Run yarn build:analyze to generate an interactive treemap visualization of the contents of all of our bundles. This will automatically open the report in your browser, or you can find the generated html page in the apps build directory at code-dot-org/apps/build/package/js/report.html. This uses webpack-bundle-analyzer.

Localization

It's especially important to test your changes with localization when modifying layouts. We support right-to-left languages and have some special layout tweaks embedded in the CSS to support that.

Running a full localization build can take several minutes. Since localization re-builds javascript files for many languages, the default build target locale is en_us

Note: Using the live-reload server with localization builds is prone to the Error: EMFILE, too many open files problem. See the ulimit fix under the live-reload server heading.

Forwarding new strings on to CrowdIn

To get new strings localized using CrowdIn, we currently run a script in a private repository. Contact a code.org engineer to trigger an update.

Adding a new npm package

To add a new package using npm, e.g., lodash, run: npm i --save-dev lodash

• --save-dev adds the dependency to node's package.json, freezing the current version
• Because the build process is done in dev mode, include dependencies as devDependencies rather than production dependencies

Contributing

We'd love to have you join our group of contributors!

For notes on our pull process, where to find tasks to work on, etc., see the Contributing Guide.

Style Guide

• In general, we follow Google's javascript style guide.
• 80 character line length.
• 2 space indent.
• 4 space indent on long line breaks.
• yarn lint should report 0 warnings or errors.
• See our project style guide for more details, including CSS/SCSS styling.

Other Docs

• Apps Build System