This repository provides a template for building browser-based research studies with the Rally platform and the WebScience library.

Before working with this template, we recommend familiarizing yourself with the following concepts.

• Implementing Research Studies as Browser Extensions
  • JavaScript - The scripting language commonly used for web applications, including browser extensions. Studies on Rally are implemented in JavaScript. If you haven't worked with JavaScript in awhile, we especially recommend catching up on modules, promises, and web workers, since those features are used in Rally, WebScience, and this template.
  • WebExtensions - An API for building browser extensions. Each study on Rally is a separate extension. If you haven't worked with WebExtensions in awhile, we recommend reviewing the structure of browser extensions, including manifests, background scripts which run in a background page, and content scripts which run on ordinary pages.
  • WebScience - A library for building browser-based research studies. WebScience provides production-quality functionality that is commonly required, difficult to implement correctly, and difficult to maintain.
  • Rally SDK - A library for integrating your study with the Rally platform. Rally SDK communicates with the Rally Web Platform, which manages user enrollment.
• Building and Testing Research Study Browser Extensions
  • ESLint - A linter for JavaScript. This template invokes ESLint with Node.js commands; you should not have to manually run ESLint or modify the ESLint configuration.
  • Node.js - A JavaScript runtime for web applications. This template uses Node.js in two primary ways. First, Node.js provides a convenient toolkit for managing JavaScript library dependencies (see npm and package.json). You can easily integrate Node.js packages from the npm public registry. Second, Node.js enables running build and test commands that are similar to makefile targets (see package scripts and npm run). You should not have to modify these Node.js commands. Note that this template does not use Node.js as a runtime for research studies.
  • Rollup - A module bundler for JavaScript. This template uses Rollup to merge module dependencies (either your own modules or npm modules) into a study extension and to remove unused code from dependencies. The template also enables using module depencies in content and worker scripts. You should not have to modify the Rollup configuration of the template.
  • web-ext - A toolkit for building and testing browser extensions. This template invokes web-ext with Node.js commands; you should not have to modify the web-ext configuration.

This template includes the following files.

• .eslintignore and .eslintrc - ESLint configuration. You should not have to modify these files.
• .gitignore - Git configuration. You should not not have to modify this file.
• CODE_OF_CONDUCT.md - The code of conduct for the study extension. You should update this file to reflect your code of conduct.
• LICENSE - The license for the study extension. You can use the provided license or your own license, so long as your license is compatible with Rally requirements and the licenses of dependencies.
• README.md - A README for the study extension. You should update this file to describe your study and its implementation.
• manifest.json - A WebExtensions manifest for the study. You should update the description, author, name, version, and homepage_url fields for your study. You can also update permissions as necessary for implementing your study. The Rally team will provide a value for the browser_specific_settings.gecko.id field.
• package.json - A Node.js package configuration for the study. You should update the name, version, description, repository, keywords, author, license, bugs, and homepage fields. You should not have to update the scripts field, which specifies a set of commands that function like makefile targets. You can add dependencies for your study implementation, either manually or with npm install. Note that you must use npm install to install dependencies and npm update to update dependencies.
• package-lock.json - A file automatically generated by Node.js package management that describes package dependencies. You should not have to manually edit this file.
• rollup.config.js - A Rollup configuration for the study. You should not have to modify this file.
• web-ext-config.js - A web-ext configuration for the study. This configuration will, on browser startup, automatically open both the Browser Console and Firefox Developer Tools for the background page. You should not have to modify this file.
• .circleci/ - CircleCI configuration.
  • config.yml - A basic CircleCI configuration for the study template. You can use this file as a starting point for your own tests, or you can safely remove the file.
• .github/ - GitHub configuration.
  • dependabot.yml - A GitHub dependency update configuration. You can use this file for managing dependency updates, or you can safely remove the file.
• src/ - The source for the study implementation. You should include all your study JavaScript files in this directory, and you can optionally include non-JavaScript assets. The build system will bundle JavaScript files to the /dist directory, as described below. The build system will also copy non-JavaScript assets (i.e., any files that do not end in .js) to the dist/ directory.
  • background.js - The main background script for the study. The build system will bundle this script and output to dist/background.js. Note that the WebExtensions manifest already specifies dist/background.js as a background script for the extension.
  • exampleContentScript.content.js - An example content script for the study. The build system automatically recognizes a *.content.js file as a content script, bundles it separately from the main background script, and outputs to the same relative path in dist/ that the file has in src/. The build system will output this content script file, for example, to dist/exampleContentScript.content.js. We provide this functionality so that study content scripts can include module dependencies.
  • exampleModule.js - An example module for the study. The build system will bundle this module into the main background script; there is no separate output in dist/. If you want to split your background script implementation into multiple files, we recommend using modules imported into background.js to benefit from performance optimizations in bundling, rather than using multiple background scripts specified in manifest.json.
  • exampleWorkerScript.worker.js - An example web worker script for the study. The build system treats *.worker.js files the same way as *.content.js files.
• tests/integration/ - A basic Selenium integration test for the study template. You can use these files as a starting point for your own tests, or you can safely remove the files.

Prerequisites: current versions of Firefox and Node.js. You might find it helpful to install Node.js with a package manager, such as Scoop on Windows, Homebrew on macOS, or apt-get on Ubuntu Linux.

1. Either fork this repository or create a new repository from this template.
2. Update the WebExtensions manifest (manifest.json) for your study. You should update the description, author, name, version, and homepage_url fields. The Rally team will provide a value for the browser_specific_settings.gecko.id field.
3. Update the Node.js package configuration (package.json) for your study. You should update the name, version, description, repository, keywords, author, license, bugs, and homepage fields.
4. In the forked repository, run npm install to install Node.js package dependencies. A new node_modules/ directory will be automatically populated with these dependencies.
5. Run npm run dev. The build system will build your study extension, launch Firefox with the study extension installed, and automatically open both the Browser Console and Firefox Developer Tools for the background page.
6. Commit your study extension to a repository! You now have a clean and functional starting point for implementing your study. If this template is updated in future, you can also easily merge those updates into your study.

This template comes with a set of predefined Node.js commands, which function similar to makefile targets. These commands should help you with study implementation, debugging, testing, and deployment. You run each command with npm run <command>.

• build - Builds the study extension, by bundling JavaScript implementation in src/ and copying non-JavaScript files. Output is in the dist/ directory.
• dev - Bundles the study extension (like build), but in developer mode, launch Firefox with the study extension installed, automatically rebuild the study if a file changes, and automatically reload the study in Firefox if the study is rebuilt. In developer mode, Rally SDK does not contact the website or the Firebase backend. Developer mode also provides a source map for bundled JavaScript, so you can use the Debugger as if the JavaScript were not bundled. You should typically use developer mode when implementing and testing your study.
• dev:emulator - Like dev, but run in emulator mode, which connects to a local Firebase emulator. See the Rally Web Platform docs for information on running a local Firebase emulator.
• lint: Run linting on the study extension.
• package: Build the study extension (build), then package the built study into an archive for distribution. Output is in the web-ext-artifacts/ directory.
• test:integration: Packages the study extension (package), then runs the provided integration test.

• Debugging the Background Script - Navigate to the browser debugging page (about:debugging), click This Firefox, then click Inspect on the study extension. The page that opens is Firefox Developer Tools for the background page, including a Web Console, JavaScript Debugger, and Network Monitor. Background script console output will also appear on the Browser Console. The template's web-ext configuration will automatically open both Firefox Developer Tools for the background page and the Browser Console on browser startup.
• Debugging a Content Script - On a page where the content script is running, open Firefox Developer Tools. The Web Console will include output from the content script, and you can select the content script in the JavaScript Debugger. Content script console output will also appear on the Browser Console.