Protocol Synchronization: Copies the "Single Source of Truth" constants (shared/constants.js) and the domain blacklist (shared/blacklist.js) from the root /shared directory into the extension/shared/ directory.
Content Script Injection: Injects protocol constants directly into content.js using marker-based replacement. This is necessary because content.js executes synchronously and cannot use ES module imports.
Artifact Generation: Compiles the extension into browser-specific bundles for Chrome and Firefox, located in the dist/ directory.

Usage

From the repository root, run:

node scripts/build-extension.js

Why this script exists

KoalaSync uses Vanilla JS in the extension to maintain zero runtime dependencies and maximum privacy. Since we don't use a bundler (like Webpack or Vite) inside the extension, this script serves as our lightweight "pre-build" step to ensure that the protocol constants remain synchronized between the extension and the relay server.

Content Injection Markers

The build script uses marker comments in content.js to locate and replace constant blocks:

Marker Pair	Injected Value	Source
`SHARED_EVENTS_INJECT_START` / `END`	The full `EVENTS` object	`shared/constants.js`
`SHARED_HEARTBEAT_INJECT_START` / `END`	`HEARTBEAT_INTERVAL` value	`shared/constants.js`

⚠️ Do NOT remove or modify these marker comments in content.js. They are required for the build script to function. If the markers are missing, the build will fail with a clear error message.